PHARM Flashcards
Which of the following agents most commonly causes a maculopapular rash in patients with infectious mononucleosis?
A. Ampicillin B. Cephalexin C. Doxycycline D. Erythromycin E. Sulfamethoxazole
A. AMPICILLIN:
Urticarial rash, not caused by a true penicillin allergy, occasionally occurs in patients taking ampicillin. However, this reaction is much more frequent in patients with infectious mononucleosis, which is a condition caused by the Epstein-Barr virus. This reaction can occur in 80% to 100% of mononucleosis patients taking ampicillin. It is most common with AMPICILLIN & AMOXICILLIN. This reaction is also seen in patients with lymphatic leukemia and those taking allopurinol. The maculopapular rash typically appears 7 to 10 days after the start of therapy and remains for several days after the medication is discontinued. The other medications, when taken by patients with infectious mononucleosis, do not produce a maculopapular rash.
- Cephalexin: first-generation cephalosporin commonly used in the treatment of skin and skin structure infections. Cephalexin, a beta-lactam antibiotic, like ampicillin, is also associated with the development of a maculopapular rash in patients with mononucleosis.
- Doxycycline: is a tetracycline antibiotic commonly used in the treatment of acne and various sexually transmitted diseases. It may also cause the development of maculopapular rash.
- Erythromycin: is a macrolide antibiotic commonly used in the treatment of upper respiratory infections and skin and skin structure infections. The incidence of maculopapular rash is rare with macrolides.
- Sulfamethoxazole: is a “sulfa” antibiotic commonly used to treat urinary tract infections. It may also cause the development of maculopapular rash.
Which of the following has prolonged action due to a renal effect?
A. Augmentin B. Sulfamethoxazole and trimethoprim C. Ampicillin and sulbactam D. Penicillin and probenecid E. Amoxicillin and clavulanate
D. PENICILLIN & PROBENECID:
Probenecid inhibits renal tubular secretion of the penicillin-type drugs, prolonging their time in the bloodstream.
- Sulfamethoxazole and trimethoprim: inhibit folic acid synthesis in bacteria and are used together to treat PCP pneumonia.
- Augmentin is amoxicillin with clavulanic acid: a beta-lactamase inhibitor.
- Ampicillin (antibiotic) can be paired with sulbactam (beta-lactamase inhibitor) for a product similar to Augmentin.
Which of the following medications has been associated with gingival hyperplasia, ataxia, and hirsutism?
A. Nifedipine B. Benazepril C. Carbamazepine D. Phenytoin E. Prochlorperazine
D. PHENYTOIN:
Gingival hyperplasia is a condition in which there is an enlargement of the gingiva due to the proliferation of fibrous connective tissue. Ataxia is associated with an inability to coordinate the skeletal muscles when performing voluntary movements. Hirsutism is a condition associated with increased hair growth. Phenytoin is a medication used in the treatment of tonic-clonic, psychomotor, and nonepileptic seizures. All of these side effects have been documented in patients taking phenytoin (choice D).
Nifedipine (CCB): treats angina & HTN; GINGIVAL HYPERPLASIA and ATAXIA but not hirsutism.
Benazepril (ACE inhib): commonly used to treat hypertension and has been associated with ATAXIA in a small number of patients.
Carbamazepine (antiepileptic): treats grand mal and psychomotor seizures; it has been associated with ATAXIA but not with gingival hyperplasia or hirsutism.
Prochlorperazine (antiemetic): treats nausea and vomiting; only ATAXIA is associated with this medication.
After an overdose of an over-the-counter (OTC) medication, a patient has marked gastrointestinal distress and tinnitus, and is lethargic and confused, with elevated body temperature. The most likely cause of these signs and symptoms is a toxic dose of
A. acetaminophen. B. acetylsalicylic acid. C. diphenhydramine. D. pseudoephedrine. E. naproxen.
B. ACETYLSALICYLIC ACID(Aspirin):
The patient has mentioned marked tinnitus, which is a classic sign for aspirin poisoning. At high salicylate blood levels, the combination of effects leading to respiratory depression (respiratory acidosis) and metabolic acidosis results in the observed pH and electrolyte changes, the anion gap, and hyperthermia.
- Acetaminophen poisoning: the patient may be asymptomatic or report anorexia, nausea or vomiting, and malaise.
- Diphenhydramine overdose: causes seizures, tachycardia, urinary retention, respiratory depression, tinnitus, nausea, vomiting, confusion, flushed skin, and inability to walk.
- Pseudoephedrine overdose: typically results in neurologic and cardiovascular anomalies, such as convulsions, changes in breathing and heart rate, and hallucinations.
- Naproxen overdose: will cause agitation, blurred vision, coma, dizziness, drowsiness, headache, wheezing, tinnitus, confusion, heartburn, nausea, and vomiting.
But note that tinnitus is a classical sign of salicylate overdose!!
Which of the following would NOT be considered a sign or symptom of withdrawal from an opiate?
A. Bradypnea B. Diarrhea C. Piloerection D. Rhinorrhea E. Sweating
A. BRADYPNEA:
The most common signs and symptoms of withdrawal are often opposite to the acute effects of the drug’s abuse. Bradypnea (choice A) would not be expected in a withdrawal situation because bradypnea and respiratory depression are seen with abuse of opiates. In fact, opiate withdrawal signs and symptoms include a mild to moderate increase in the respiratory rate. Common signs and symptoms of withdrawal include diarrhea (choice B), piloerection (choice C), rhinorrhea (choice D), and sweating (choice E).
For the treatment of urinary tract infections, a patient is prescribed sulfamethoxazole/trimethoprim. This agent is believed to exert its antibacterial effect by which of the following mechanisms?
A. Competitive inhibition of para-amino-benzoic acid B. Inhibition of bacterial cell-wall synthesis C. Inhibition of DNA-gyrase D. Irreversible binding to the 30s subunit of bacterial ribosomes E. Irreversible binding to the 50s subunit of bacterial ribosomes
A. COMPETITIVE INHIBITION OF PARA-AMINO-BENZOIC ACID:
Sulfonamide antibiotics, such as sulfamethoxazole/trimethoprim, exert their antibacterial effect through the competitive inhibition of para-amino-benzoic acid (PABA), thereby inhibiting folic acid biosynthesis, which is required for bacterial growth. This agent is commonly used for the treatment of urinary tract infections.
- Penicillins: exert their antibacterial effect through the inhibition of BACTERIAL CELL WALL SYNTHESIS. These agents bind to one or more of the penicillin-binding proteins located on the cell walls of susceptible organisms. This action results in the inhibition of the third and final stage of bacterial cell-wall synthesis.
- Quinolone: antibiotics inhibit DNA-gyrase, which is an enzyme necessary for bacterial DNA REPLICATION & REPAIR.
- Aminoglycosides: such as gentamicin, irreversibly bind to the 30s subunit of bacterial ribosomes, which inhibits BACTERIAL PROTEIN SYNTHESIS.
- Lincosamides: such as clindamycin, irreversibly bind to the 50s subunit of bacterial ribosomes, which suppresses BACTERIAL PROTEIN SYNTHESIS.
- Macrolides: such as erythromycin, reversibly bind to the 50s subunit of bacterial ribosomes, which suppresses BACTERIAL PROTEIN SYNTHESIS.
Interaction of aspirin with which of the following drugs can cause increased bleeding?
A. Triazolam B. Barbiturates C. Ibuprofen D. Coumadin
D. COUMADIN:
Aspirin is a nonsteroidal anti-inflammatory drug (NSAID). These medications are usually prescribed for relief of fever, pain, and inflammation. An important feature of aspirin is its ability to inhibit platelet aggregation. Daily low dose of aspirin prolongs the bleeding time. The combination of aspirin with warfarin (Coumadin) leads to a 1.5 to 2-fold increase in bleeding episodes compared with warfarin (Coumadin) therapy alone. A dose adjustment based on the prothrombin time or International Normalized Ratio (INR) is necessary.
Triazolam, barbiturates, and pentobarbital are safe to take along with aspirin.
Frequent administration of Ibuprofen with aspirin may decrease the effectiveness of aspirin (in preventing heart attacks or strokes). In addition, combining these medications may increase the risk of developing gastrointestinal ulcers and bleeding. A dose adjustment or more frequent monitoring is required when prescribing both the medications together.
An increase in the cytosolic concentration of norepinephrine in sympathetic nerve endings leads to
A. activation of dopa decarboxylase. B. increased release of norepinephrine. C. inhibition of tyrosine hydroxylase. D. stimulation of MAO.
C. INHIBITION OF TYROSINE KINASE:
Tyrosine hydroxylase, the rate-limiting step in the synthesis of NE in sympathetic nerve endings, is subject to feedback inhibition by NE (choice C). In some sympathetic nerve endings (e.g., in the heart), tyrosine hydroxylase is also inhibited via NE activation of prejunctional alpha2 receptors. Tyrosine hydroxylase (TyrH) catalyzes the hydroxylation of tyrosine to L-DOPA. Aromatic amino acid decarboxylase (choice A) catalyzes the cytosolic conversion of L-DOPA to dopamine, Dopamine-β -hydroxylase hydroxylates dopamine to norepinephrine, which is methylated to epinephrine (choice B) by phenylethanolamine N-methyltransferase. Inhibition of TyrH leads to impaired synthesis of dopamine as well as epinephrine and norepinephrine. An increase in the cytosolic concentration of norepinephrine in sympathetic nerve endings does not stimulate MAO (choice D). Monoamine oxidases inhibitors increase the free cytosolic concentrations of norepinephrine, serotonin, and dopamine in neuronal cells and in synaptic vesicles.
All of the following are single-dose regimens for antibiotic prophylaxis of endocarditis during dental procedures in adults EXCEPT one. Which one is this EXCEPTION?
A. Clindamycin (600 mg) B. Amoxicillin (2 grams) C. Azithromycin (500 mg) D. Cephalexin (500 mg) E. Clarithromycin (500 mg)
D. Cephalexin(500mg): Should be 2g.
Oral, as well as IV or IM medications, are to be given 30 minutes to 1 hour before a dental procedure. With respect to dental procedures, all of the listed single-dose regimens for antibiotic prophylaxis of endocarditis (choices A, B, C, and E) are accurate except for cephalexin (500 mg) (choice D). For this medication, the quantity should be 2 grams.
Amoxicillin, Cephalexin: (2 grams)
Azithromycin, Clarithromycin: (500 mg)
Clindamycin: (600mg)
Which antibiotic is never used to treat anaerobes?
A. Metronidazole B. Streptomycin C. Chloramphenicol D. Azithromycin E. Vancomycin
B. STREPTOMYCIN:
Streptomycin enters bacterial cells through an oxygen-dependent process. Therefore, it cannot be used in anaerobic infections. Streptomycin is an inhibitor of the 30S subunit of the bacterial ribosome and is in the aminoglycoside family of antibiotics with neomycin, gentamicin, and amikacin. It is sometimes used as an antimycobacterial. It is administered intravenously or intramuscularly. It is sometimes used in combination with beta-lactam-type antibiotics.
- Metronidazole: works by stopping the growth of bacteria and some parasites.
- Chloramphenicol and azithromycin: treat bacterial infections, most commonly conjunctivitis.
- Vancomycin: is linked to the treatment of Clostridium difficile.
A patient using NSAIDs for chronic pain develops a bleeding ulcer and suffers considerable pain and blood loss. Which one of the following is most likely to occur if the patient stands up quickly?
A. Bradycardia B. Bronchospasm C. Miosis D. Salivation E. Sweating
E. SWEATING:
Blood loss from any cause will elicit increased sympathetic outflow, as does pain. In a patient who is hypotensive because of blood loss, the act of standing up could possibly increase signs and symptoms of sympathetic stimulation, including tachycardia, bronchiolar dilation, mydriasis, dry mouth, and sweating.
A 12.5 kg child presents to your office with fever and mandibular buccal swelling. An exam reveals an abscessed tooth #T. You prescribe amoxicillin in liquid form. Which of the following prescriptions correctly results in the desired dosage of 40 mg/kg each day?
A. Amoxicillin susp. 250 mg/5ml, 1 tsp Q6h B. Amoxicillin susp. 125 mg/5ml, 2 tsp Q8h C. Amoxicillin susp. 250 mg/5ml, 1 tsp TID D. Amoxicillin susp. 125 mg/5ml, 1 tsp QID
D. Amoxicillin susp. 125mg/5ml, 1tsp QID
The best method for calculating this is to find out how much total antibiotic is required first. A dosage of 40 mg/kg times 12.5 kg body weight results in 500 mg of antibiotic required per day. Let’s see what each answer gives us. Remember that a teaspoon is 5 ml. Choice A will give us 250 mg in a teaspoon and 1 teaspoon every 6 hours (4 times a day) for 1,000 mg total. Choice B will give us 125 mg in a teaspoon, or 250 mg in 2 teaspoons, every 8 hours (three times a day) for 750 mg total. Choice C will give us 250 mg in a teaspoon and 1 teaspoon three times a day for 750 mg total. Choice D will give us 125 mg in a teaspoon and 1 teaspoon 4 times a day for 500 mg total; therefore, choice D is correct.
Which one of the following is LEAST likely to be an effect of histamine?
A. Bronchiolar constriction B. Hypotension C. Activation of type C pain fibers D. Increased gastric secretion E. Decreased capillary permeability
E. Decreased capillary permeability:
The activation of H1 receptors in bronchiolar smooth muscle leads to contraction, which leads to bronchoconstriction, but in vascular smooth muscle relaxation could lead to hypotension. H1 receptor activation increases the firing rate of the C-type afferent pain fibers in the periphery and increases gastric acid secretion. However, the release of histamine is associated with urticaria and edema because of increased capillary permeability, not decreased permeability.
All of the following are common signs and symptoms of withdrawal that an opiate abuser might experience, EXCEPT:
A. bradypnea. B. diarrhea. C. piloerection. D. rhinorrhea. E. sweating.
A. BRADYPNEA:
The time to the onset, intensity, and duration of acute withdrawal symptoms secondary to opiate abuse are influenced by several factors including the amount taken on a daily basis, the length of the drug abuse, and the half-life of the opiate. The most common signs and symptoms of withdrawal are often the opposite to the acute effects of drug abuse. With this concept in mind, bradypnea would not be expected in a withdrawal situation, since bradypnea and respiratory depression are seen with abuse of opiates. In fact, opiate withdrawal signs and symptoms include mild to moderate increases in the respiratory rate (tachypnea). Common signs and symptoms of withdrawal that an opiate abuser might experience include diarrhea, piloerection, rhinorrhea, and sweating. Other common signs and symptoms include coughing, lacrimation, and muscle twitching as well as elevations in body temperature and blood pressure.
Which of the following antihypertensive medications is commonly used to preserve ventricular function in patients with congestive heart failure as well as preserve the function of the kidneys of diabetic patients?
A. Atenolol B. Captopril C. Furosemide D. Methyldopa E. Verapamil
B. CAPTOPRIL:
Captopril is an angiotensin-converting enzyme (ACE) inhibitor indicated for the treatment of hypertension and congestive heart failure, as it has been proven to preserve ventricular function. This agent is commonly used for the treatment of hypertension in diabetic patients, as it has been shown to preserve kidney function.
- Atenolol: is a beta-receptor-blocking agent commonly used in the treatment of hypertension. The usage of beta-adrenergic-blocking agents, such as atenolol, may blunt or prevent the appearance of the premonitory signs and symptoms of hypoglycemia in diabetics and may worsen ventricular function in congestive heart failure patients.
- Furosemide: is a potent diuretic commonly used in the treatment of edema associated with congestive heart failure and hypertension. However, the use of this medication in diabetic patients is not recommended, since it can cause hyperglycemia and glucose intolerance.
- Methyldopa: a centrally acting alpha-adrenergic agonist, can be safely used to treat hypertension in diabetic patients. However, due to the severity and frequency of adverse effects associated with this medication, it is not commonly used.
- Verapamil: is a calcium-channel blocker indicated for the treatment of hypertension, supraventricular tachycardias, and various types of angina; it can be used safely and effectively for the treatment of hypertension in diabetic patients; however, it is not safe for usage in heart failure patients, as it has strong negative inotropic effects.
A patient was given two 1.8ml carpules of 2% lidocaine with epinephrine 1:100,000. How much epinephrine was administered?
A. 0.18 mg B. 0.018 mg C. 0.36 mg D. 0.036 mg E. None of the above
D. 0.036 mg
Each standard anesthetic carpule contains 1.8 ml of solution, which has a mass of approximately 1.8 grams. 1.8 grams equals 1,800 mg. 100,000th of this amount is epinephrine. So we divide 1,800 by 100,000 or 1.8 × 103 is divided by 1 × 105. You’ll get 1.8 × 10− 2 or 0.018 mg (0.018 mg per carpule or 0.036 mg in 2 carpules) (choice D). Hence, choices A, B, C and E are incorrect.
Lorazepam is believed to exert its anxiolytic effects by which of the following mechanisms?
A. Blocking alpha-adrenergic receptors B. Blocking beta-adrenergic receptors C. Increasing the release of norepinephrine from central noradrenergic neurons D. Inhibiting biogenic amine reuptake at the presynaptic neuron E. Potentiating the effects of gamma-aminobutyrate (GABA)
E. Potentiating the effects of GABA:
Lorazepam is a sedative hypnotic with short onset of effects and relatively long half-life; It increases the action of GABA, which is a major inhibitory neurotransmitter in the brain. Lorazepam may depress all levels of the CNS, including limbic and reticular formation.
- Agents such as Doxazosin and Terazosin that block alpha-adrenergic receptors are indicated for the treatment of hypertension and benign prostatic hyperplasia (BPH).
- Medications such as propranolol and metoprolol are known as beta-blockers, since they block beta-adrenergic receptors. Beta-blockers are indicated for the treatment of hypertension and angina pectoris as well as various other cardiovascular conditions.
- Amphetamines act by increasing the release of norepinephrine from central noradrenergic neurons. They are indicated for the treatment of narcolepsy, attention deficit disorder with hyperactivity, and exogenous obesity.
- Tricyclic antidepressants, such as amitriptyline and doxepin, possess three pharmacologic actions in varying degrees: These agents inhibit biogenic amine (norepinephrine and possibly serotonin) reuptake at the presynaptic neuron, they induce sedation, and they produce central and peripheral anticholinergic actions. They are indicated for the treatment of depression with or without anxiety and/or sleep disturbances.
- Benzodiazepines are ideal for oral conscious sedation in the dental field. It is important to properly review each patient’s medical history for contraindications before prescribing. Remember that the antidote for benzo overdose flumazenil (Romazicon). Caution is advised while prescribing benzodiazepines. It is important to remember that benzodiazepines plus opioids or CNS depressants equal sedation, respiratory depression, coma, and death. They are not recommended in patients with primary depressive disorder, psychosis, or respiratory disease. Use with caution in patients with impaired gag reflex. They may cause CNS depression, impairing physical and mental abilities; caution patients to not operate dangerous machinery or motor vehicles. Use with caution during surgeries or procedures in children younger than 3 years or in pregnant women during their third trimester.
A 500 mg dose of a drug has therapeutic efficacy for 6 hours. If the half-life of the drug is 8 hours, for how long would a 1 gram dose be effective?
A. 8 hours B. 12 hours C. 14 hours D. 16 hours E. 24 hours
C. 14 hours:
The fact that the drug has therapeutic efficacy for 6 hours has no direct relationship to its half-life, but simply means that the drug is above its minimal effective concentration for 6 hours. Doubling the dose to 1 gram means that the drug level will be above the minimum for a longer period of time. Because the elimination half-life is 8 hours, 500 mg of the drug will remain in the body for 8 hours after a dose of 1 gram. Thus the total duration of effectiveness will be 8 + 6 = 14 hours (choice C). Hence, other choices A, B, D and E are incorrect.
Which of the following statements regarding beta-lactamase inhibitors is NOT true?
A. Clavulanic acid is the beta-lactamase inhibitor that is combined with amoxicillin in the brand name product Augmentin. B. They irreversibly inactivate bacterial beta-lactamase activity. C. They dramatically improve the effectiveness of a beta-lactamase-sensitive penicillin. D. They possess strong antimicrobial activity. E. They prevent the inactivation of antibiotics sensitive to the enzyme beta-lactamase.
D. Possess antimicrobial activity:
The beta-lactamase inhibitors are compounds that are added to antibiotics to help increase the effectiveness of the antibiotic. The most common beta-lactamase inhibitors are clavulanic acid, sulbactam, and tazobactam. These compounds possess weak or no antimicrobial activity. Clavulanic acid is the beta-lactamase inhibitor that is combined with amoxicillin in the brand name product Augmentin (choice A). Since they irreversibly inactivate bacterial beta-lactamase enzymes (choice B), they dramatically improve the effectiveness of a beta-lactamase-sensitive penicillin (choice C) by preventing the inactivation of antibiotics sensitive to the enzyme beta-lactamase (choice E).
Which of the following is the most serious potential consequence of ingestion of a petroleum distillate hydrocarbon, such as gasoline?
A. Aspiration of the hydrocarbon into the respiratory tract B. Central nervous system excitation C. Corrosive action of the poison on the stomach lining D. Destruction of digestive enzymes E. Paralysis of peristaltic motion in the intestinal tract
A. Aspiration of hydrocarbon into the respiratory tract:
Hydrocarbons exist in a number of forms, including petroleum distillate hydrocarbons (such as gasoline, kerosene, and lacquer thinner), aromatic hydrocarbons (such as xylene and toluene), and halogenated hydrocarbons (such as carbon tetrachloride). Petroleum distillate hydrocarbons are particularly toxic to the lungs, central nervous system, and intestinal tract. Aspiration of the hydrocarbon into the respiratory tract typically results in aspiration pneumonitis. Respiratory symptoms typically include cough, dyspnea, tachypnea, hypoxia, and cyanosis. As a general rule, all hydrocarbons are central nervous system depressants and do not cause central nervous system excitation. They do produce a corrosive action on the stomach lining; however, this form of toxicity is often mild. Although they do destroy the digestive enzymes of the intestinal tract, this is not a mechanism for significant toxicity. Intestinal toxicity is primarily related to the corrosive effect on the intestinal lining. Paralysis of peristaltic motion in the intestinal tract is typically not seen.
What is the proper cephalexin dosage for a 20-kg child?
A. 300 g B. 400 g C. 500 g D. 1.0 gram E. 2.0 grams
D. 1g
At a children’s dosage of 50 mg/kg, a 20-kg child should receive 20 X 50 = 1,000 mg, or 1.0 gram, of cephalexin. This does not exceed the adult dose of 2.0 grams (choice E). Choices A, B, and C are also incorrect.
A patient who was recently diagnosed with clinical depression is to be prescribed a beta-blocker for the treatment of hypertension. Which of the following is LEAST likely to worsen the patient’s CNS signs and symptoms?
A. Atenolol B. Metoprolol C. Labetalol D. Penbutolol E. Propranolol
A. Atenolol:
As a general rule, the more lipophilic the beta-blocker, the higher the CNS penetration and subsequent incidence of CNS-related adverse reactions. These effects may disappear in an individual previously prescribed a highly lipophilic agent when a less lipophilic agent is substituted. The most common CNS side effects of the beta-blockers include dizziness, vertigo, headache, mental depression, peripheral neuropathy, and bizarre dreams. The lipid solubility of the agents listed is as follows: atenolol is low; metoprolol and labetalol are moderate; and penbutolol and propranolol are all highly lipid soluble.
Solubility scale:
Penbutolol, Propranolol: highly lipid soluble
Labetalol, Metoprolol: moderate
Atenolol: low
Hydrochlorothiazide is a diuretic used in the treatment of hypertension and has been associated with which of the following?
A. Decreased total cholesterol blood levels B. Hyperkalemia C. Hypernatremia D. Decreased glucose tolerance
D. Decreased glucose tolerance:
Hydrochlorothiazide is known to increase fasting blood glucose, especially in diabetic patients; therefore, this medication decreases glucose tolerance. In diabetic patients, it may be necessary to make dosage adjustments of both oral hypoglycemic agents and/or insulin to maintain euglycemia when taken concomitantly with this medication. Hydrochlorothiazide is associated with increased blood levels of uric acid, increased total cholesterol blood levels, hypokalemia, and hyponatremia.
A young man is prescribed dextroamphetamine; this agent is believed to exert its mechanism of action by which of the following ways?
A. Blocking alpha-adrenergic receptors B. Blocking beta-adrenergic receptors C. Increasing the release of norepinephrine from central noradrenergic neurons D. Inhibiting biogenic amine reuptake at the presynaptic neuron E. Potentiating the effects of gamma-aminobutyrate (GABA)
C. Increasing the release of norepinephrine from central noradrenergic neurons:
- Amphetamines such as dextroamphetamine act by increasing the release of norepinephrine from central noradrenergic neurons. They are indicated for the treatment of narcolepsy, attention deficit disorder with hyperactivity, and exogenous obesity.
- Agents such as doxazosin and terazosin that block alpha-adrenergic receptors are indicated for the treatment of hypertension and benign prostatic hyperplasia (BPH).
- Medications such as propranolol and metoprolol are known as beta-blockers because they block beta-adrenergic receptors. Beta-blockers are indicated for the treatment of hypertension, angina pectoris, and various other cardiovascular conditions.
- Tricyclic antidepressants, such as amitriptyline and doxepin, possess three pharmacologic actions in varying degrees: These agents inhibit biogenic amine (norepinephrine and possibly serotonin) reuptake at the presynaptic neuron, they induce sedation, and they produce central and peripheral anticholinergic actions. They are indicated for the treatment of depression with or without anxiety and/or sleep disturbances.
- Benzodiazepines, such as lorazepam, potentiate the effects of gamma-aminobutyrate (GABA). When GABA’s effect is potentiated, the net result is an antianxiety effect.
Use of which of the following agents increases the risk for developing an oral fungal infection?
A. Albuterol inhalation B. Beclomethasone inhalation C. Terbutaline inhalation D. Cromolyn inhalation E. Ipratropium inhalation
B. Beclomethasone inhalation:
Oral fungal infections can be caused by a number of factors. Patients receiving oral or inhalation corticosteroids, antibiotics, chemotherapy, and local irradiation as well as those with compromised immune systems commonly develop oral fungal infections. Candidiasis is the most common type of fungal infection seen in these patients. Beclomethasone inhalation commonly causes oral fungal infections since it is classified as a corticosteroid. This agent is used in the treatment of bronchial asthma because it decreases inflammation and edema in the respiratory tract. The risk for developing an oral fungal infection when using beclomethasone inhalation can be substantially decreased when individuals rinse out their mouth with water after each usage.
- Both albuterol and terbutaline inhalation are used to relieve bronchospasm associated with acute or chronic asthma. These agents are potent beta-2-receptor agonists and cause almost immediate bronchodilation. The major side effects of these agents are tachycardia and CNS stimulation.
- Cromolyn inhalation is a mast-cell stabilizing (antihistaminic) agent used primarily for the prophylaxis of mild to moderate seasonal and perennial bronchial asthma and allergic rhinitis. The major disadvantage of this agent is that it has a very slow onset of action; it may take several weeks to achieve a desired effect. Cromolyn has very few side effects and is generally well-tolerated.
- Ipratropium inhalation is used to relieve bronchospasm associated with COPD. The major side effects associated with this agent include blurred vision, bitter taste, and cough.
A patient’s heart rate is most likely to increase when taking which of the following cardiovascular medications?
A. Amlodipine B. Diltiazem C. Nitroglycerin D. Verapamil E. Atenolol
C. Nitroglycerin:
Tachycardia, or increased heart rate, is likely to occur when the cardiac muscle is directly stimulated or when there is a relaxation (vasodilation) of vascular smooth muscle leading to a “pooling” of blood in the venous system, as seen in patients receiving nitroglycerin. Nitroglycerin is indicated for the prevention of angina.
- The calcium-channel blockers, such as amlodipine, diltiazem, and verapamil, decrease intracardiac contractility; hence, they are not likely to cause tachycardia.
- Atenolol is a beta-receptor antagonist that is indicated for the treatment of hypertension and for the treatment of angina since it decreases heart rate. Therefore, this agent is likely to cause bradycardia, not tachycardia.
Which of the following sulfonamides is a short-acting oral agent associated with a high incidence of crystalluria?
A. Silver sulfadiazine B. Sulfacetamide C. Sulfadiazine D. Sulfasalazine E. Sulfasoxazole
C. Sulfadiazine:
Sulfadiazine is a sulfonamide antibiotic that is a short-acting oral agent associated with a high incidence of crystalluria; therefore, patients must maintain good hydration when receiving this oral medication. This agent is used primarily in the treatment of urinary tract infections.
- Silver sulfadiazine is a topical product used primarily for prevention of bacterial colonization of a burn wound.
- Sulfacetamide is most commonly used as a topical solution to treat a variety of ophthalmic infections.
- Sulfasalazine is an agent used primarily in the treatment of ulcerative colitis. Because intestinal tract absorption is very poor, the incidence of crystalluria is very low.
- Sulfasoxazole is a sulfonamide antibiotic that is a short-acting oral agent associated with a low incidence of crystalluria. This agent is used primarily in the treatment of urinary tract infections.
Which of the following is the MOST common life-threatening complication of general anesthesia in a pregnant woman?
A. Aspiration B. Atelectasis C. Eclampsia D. Hypotension E. Visceral pain
A. Aspiration:
When the acidic gastric contents, including undigested foods, are aspirated into the lungs, severe respiratory distress will occur. In some cases, the degree of respiratory distress is so severe that death can occur. Pregnant women are at a higher risk for aspirating the gastric contents into the lungs due to the increased pressure on the stomach. The incidence of aspiration can be dramatically decreased in pregnant women who fast around 8 to 12 hours prior to general anesthesia. Neutralization of the stomach pH is also recommended. Although atelectasis can occur within the first 24 hours after general anesthesia, it is typically not life-threatening. Eclampsia is not a frequent side effect of general anesthesia in pregnant women. Hypotension does not frequently occur with general anesthesia in pregnant women; however, this is a frequent side effect of epidural anesthesia. Visceral pain may occur; however, pain is not considered a life-threatening side effect.
Which of the following agents exerts its pharmacologic effects by inhibiting the reuptake of both serotonin and norepinepherine from the presynaptic receptors in the CNS?
A. Amitriptyline B. Diazepam C. Fluoxetine D. Haloperidol E. Meperidine
A. AMITRIPTYLINE:
Amitriptyline is a tricyclic antidepressant used primarily in the treatment of endogenous depression. It exerts its pharmacologic effects by inhibiting the reuptake of both serotonin and norepinepherine from the presynaptic receptors in the CNS.
- Diazepam is a benzodiazepine used in the treatment of various anxiety disorders, in the treatment of status epilepticus, and as a premedication for many different surgical procedures. It binds to the benzodiazepine site on neuronal GABA receptors and enhances GABA-mediated chloride influx.
- Fluoxetine is classified as an SSRI (selective serotonin-reuptake inhibitor) antidepressant used in the treatment of depression and various psychotic disorders. It exerts its pharmacologic effects by inhibiting the reuptake of serotonin from the presynaptic receptors in the CNS.
- Haloperidol is a butyrophenone antipsychotic used in the management of various psychotic disorders; it is a dopamine-receptor-blocking agent.
- Meperidine is an opiate-receptor agonist indicated for the treatment of moderate to severe pain.
Which of the following antidepressants would be most recommended in a patient who recently experienced a myocardial infarction?
A. Desipramine B. Doxepin C. Fluoxetine D. Phenelzine E. Trazodone
C. Fluoxetine:
A myocardial infarction results from prolonged myocardial ischemia, precipitated by a decreased perfusion to the myocardial tissue. In most cases, myocardial ischemia is caused by an occlusive coronary thrombus. As a general rule, agents that increase the heart rate or decrease myocardial perfusion are not recommended in patients with a past medical history significant for a myocardial infarction.
Fluoxetine is a selective serotonin-reuptake inhibitor (SSRI) used in the treatment of depression and obsessive-compulsive disorders. This agent would be most recommended in a patient who recently experienced a myocardial infarction because it produces little, if any, adverse cardiovascular effects.
- Both desipramine and doxepin are tricyclic antidepressants indicated for the treatment of depression. These agents are not recommended for individuals with a recent myocardial infarction because they possess strong anticholinergic effects, which can lead to angina pectoris, conduction disturbances, and sinus tachycardia.
- Phenelzine is a monoamine oxidase inhibitor indicated as a second-line agent in the treatment of depression when other, less toxic, agents are unsuccessful. This agent is associated with CNS and cardiac stimulation, blood pressure changes, and orthostatic hypotension.
- Trazodone is a tetracyclic antidepressant agent associated with cardiac arrhythmias, tachycardia, and angina pectoris.
The use of which of the following medications in a 16-year-old male would most likely be associated with the development of serum-like sickness?
A. Cefaclor B. Chloramphenicol C. Phenobarbital D. Procainamide E. Sulfamethoxazole/trimethoprim
A. CEFACLOR:
Cefaclor is a second-generation cephalosporin used in the treatment of a variety of upper and lower respiratory infections. This antibiotic has been associated with the development of a serum-like sickness, especially when administered to infants and young adults. The reaction most commonly seen with the agent commonly results in the development of erythema multiforme, rash, and arthralgias.
- Chloramphenicol is a broad-spectrum antibiotic used in the treatment of many different infections. This agent is known to cause a disorder called “gray baby syndrome” when given to infants.
- Phenobarbital is an anticonvulsant used in the treatment of tonic-clonic seizures; it is associated with the development of agranulocytosis as well as other blood dyscrasias.
- Procainamide is a Class IA antiarrhythmic used in the prevention of paroxysmal atrial fibrillation and tachycardia and is associated with the development of systemic lupus erythematous (SLE), which is an inflammatory autoimmune disorder that can affect multiple organ systems. Characteristic signs and symptoms of this disease can include fever, anorexia, malaise, malar rash (butterfly rash), photosensitivity, arthritis, serositis, and various hematological and immunological abnormalities.
Other medications associated with the development of SLE include hydralazine, chlorpromazine, isoniazid, methyldopa, and quinidine.
- Sulfamethoxazole/trimethoprim is a sulfa antibiotic primarily used in the treatment of urinary tract infections. This agent has been associated with the development of blood dyscrasias, especially in the elderly and in those with some degree of immunosuppression.
The most common manifestation of lidocaine toxicity is
A. CNS dysfunction. B. hypertension. C. drug fever. D. hypokalemia. E. torsades.
A. CNS DYSFXN:
Lidocaine is the least likely antiarrhythmic agent to cause cardiac depression but does cause CNS effects, which can range from drowsiness to excitation, culminating in seizures. The drug has vasodilating actions, leading to decreases in blood pressure. It does not cause drug fever or change plasma K+ levels. Lidocaine can have an initial beneficial effect in treating torsades.
A 23-year-old man is noted to have signs and symptoms similar to those seen in his grandfather, who was recently diagnosed with Parkinson disease. On the basis of this information, the patient was most likely prescribed which of the following?
A. Cimetidine B. Bumetanide C. Haloperidol D. Pirbuterol E. Sucralfate
C. HALOPERIDOL:
A patient presenting with signs and symptoms of Parkinson disease is most likely receiving a medication that blocks the action of dopamine. Remember, Parkinson disease is caused by a relative deficiency of dopamine in the CNS. Of the agents listed, only haloperidol has dopamine-receptor blocking properties. Haloperidol is an antipsychotic indicated for the treatment of a variety of psychotic disorders. One of the major side effects of this medication is the development of Parkinson-like syndrome. It is important to note that drug-induced Parkinson disease is indistinguishable from idiopathic Parkinsonism and is usually reversible in a few weeks upon discontinuation. However, the severity and duration of the signs and symptoms from the drug-induced Parkinson disease is often more pronounced when it occurs in patients with established Parkinson disease.
- Cimetidine is an H-receptor antagonist used in the treatment of GERD and gastric ulcers; this agent is generally well tolerated with very little incidence of side effects.
- Bumetanide is a loop diuretic indicated for the treatment of various edematous states. This agent is known to cause incontinence and dizziness.
- Pirbuterol is a beta-receptor agonist indicated for the treatment of asthma. Although this agent is generally well tolerated with very little incidence of side effects, CNS excitation can occur.
- Sucralfate is a basic aluminum salt that forms an ulcer adherent complex at the site of the ulcer and is indicated for the treatment of duodenal ulcer. Constipation is the most common side effect of this agent.
A 42-year-old male presents to the emergency room with a priapism that spontaneously occurred 4.5 hours earlier without any form of sexual stimulation. If the patient states that he is receiving pharmacologic treatment for hypertension, type 2 diabetes, and major depression, the most likely agent causing his current condition is:
A. atenolol. B. bumetanide. C. glipizide. D. paroxetine. E. trazodone.
E. Trazodone:
Priapism is a condition associated with the development of a painful erection for an extended period of time. When untreated, priapism can cause severe tissue damage that can lead to the development of impotence. Priapism has been reported in patients receiving trazodone for the treatment of depression. In patients with prolonged or inappropriate penile erection, this medication should be discontinued, and medical attention should be sought immediately. Injection of alpha-adrenergic stimulants, such as norepinephrine or epinephrine, may be successful in treating the priapism. Surgical intervention may be necessary.
- Atenolol is a beta-receptor blocking agent indicated for the treatment of hypertension; this agent is commonly associated with the development of impotence in males.
- Bumetanide is a loop diuretic indicated for the treatment of edema and hypertension; electrolyte abnormalities are the most common side effects seen with this agent.
- Glipizide is a sulfonylurea oral hypoglycemic agent indicated for the treatment of type 2 diabetes; hypoglycemia is the most common side effect of this agent.
- Paroxetine is a selective serotonin-reuptake inhibitor (SSRI) indicated for the treatment of depression. This agent is commonly associated with the development of impotence in males. With respect to the other SSRls, this agent has the highest incidence of causing impotence in males.
Which of the following, when added to a local anesthetic, will accelerate the penetration of the anesthetic into the nerve sheath?
A. Epinephrine B. Meperidine C. Sodium bicarbonate D. Sodium chloride E. Sodium metabisulfite
C. SODIUM BICARBONATE:
Local anesthetics are used to block pain conduction by nerves. They are commonly used for infiltration anesthesia, local nerve blocks, spinal nerve blocks, and epidural nerve blocks. Local anesthetics inhibit nerve conduction by decreasing the permeability of the neuronal membrane to sodium, which prevents the sodium influx required for propagation of action potentials. Their onset of action is dependent upon the pH at the injection site, lipid solubility, protein binding, and molecular size. Local anesthetics are compounds that have a pH greater than 7. In other words, they can be classified as “basic” compounds. In an acidic environment, the compound will be in an ionized form. With these concepts in mind, the pH at the injection site is important because only the non-ionized form of the local anesthetic can be absorbed into the nerve. Therefore, the addition of a base such as sodium bicarbonate will accelerate the penetration of the nonionized local anesthetic into the nerve sheath.
- Epinephrine is commonly used in local anesthetic injections because it causes local vasoconstriction of the surrounding tissue, thereby reducing the rate of lidocaine removal from the local injection site.
- The addition of meperidine, an opioid analgesic, would not alter the rate of absorption of the local anesthetic into the nerve.
- Sodium chloride is used in anesthetic solutions to adjust the iso-tonicity of the solution.
- Sodium metabisulfite is used as a preservative; it does not affect the penetration rate of the local anesthetic into the nerve sheath.
A 26-year-old woman presents with a bilateral chronic inflammation of the lid margins, which is associated with crusting, itching, and discharge around the lids. If this infection were caused by Staphylococcus aureus, the most appropriate therapy would be which of the following?
A. Intramuscular ceftriaxone B. Oral erythromycin C. Oral tetracycline D. Topical erythromycin ointment E. Topical ketorolac
D. TOPICAL ERYTHROMYCIN OINTMENT:
Blepharitis is an inflammation of the lid margins that is generally a bilateral and chronic condition. The two main types of blepharitis are staphylococcal and seborrheic. This condition is characterized by redness and irritation of the eyelids. Signs and symptoms range from mild to severe and include crusting, discharge, ocular discomfort, itching, scaling, and photophobia. Staphylococcal blepharitis is common and, when untreated, can lead to chronically red eyelid margins and scarring.
Staphylococcal and ulcerative blepharitis are best treated with topical ophthalmic ointments, such as erythromycin, bacitracin, tetracycline, and sulfonamides. The most commonly used treatment is erythromycin ointment.
- Intramuscular ceftriaxone: is commonly used for the treatment of gonococcal conjunctivitis.
- The most common treatment measures for chlamydial keratoconjunctivitis include either oral erythromycin or oral tetracycline.
- Topical ketorolac is commonly used for the treatment of ocular inflammation.
The side effects of cyclobenzaprine would be expected to be mostsimilar to which of the following?
A. Amitriptyline B. Dantrolene C. Ketoprofen D. Lorazepam E. Tetracycline
A. AMITRIPTYLINE:
Cyclobenzaprine is a centrally acting skeletal muscle relaxant that is structurally and pharmacologically related to tricyclic antidepressants. Cyclobenzaprine is used short-term as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute musculoskeletal conditions. Like tricyclic antidepressants, the most common side effects are dry mouth, drowsiness, dizziness, weakness, fatigue, tachycardia, urinary retention and abdominal cramping. Since amitriptyline is a tricyclic antidepressant, the side effects of cyclobenzaprine would be expected to be most similar to amitriptyline.
- Dantrolene is also a centrally acting skeletal muscle relaxant; however, it is structurally and pharmacologically related to hydantoin derivatives, such as phenytoin. Although dantrolene produces the same CNS effects as cyclobenzaprine, it does not produce anticholinergic side effects, such as dry mouth and urine retention.
- Ketoprofen is a non-steroidal anti-inflammatory drug used in the treatment of mild to moderate pain caused by inflammation; its most common side effects are intestinal discomfort and dizziness.
- Lorazepam is a benzodiazepine used in the management of anxiety disorders and for the short term relief of anxiety. Lorazepam is associated with the development of drowsiness, sedation, dizziness and weakness.
- Tetracycline is an antibiotic used primarily in the treatment of various sexually transmitted diseases and acne. Its major side effects include diarrhea, gastrointestinal upset and phototoxicity.
In orthodontic procedures, the placement of which appliances will normally require antibiotic prophylaxis in a susceptible patient?
A. Bands, but not brackets B. Brackets, but not bands C. Both brackets and bands D. Neither brackets nor bands
A. bands, not brackets:
Even if your memory fails you, use the basic principles of this subject to guide you. Only procedures inducing bacteremia need to be premedicated. Orthodontic bands can cut into gingival tissue and cause significant bleeding and subsequent bacteremia. Therefore, it is recommended that bands, but not brackets be premedicated. Orthodontic brackets (choices B and C) are generally bonded to coronal tooth structure and no bleeding occurs. Choice D is also incorrect.
Kernicterus is a drug-induced disorder that may be seen in infants whose mothers received which of the following medications during pregnancy?
A. Acetaminophen B. Chloramphenicol C. Diethylstilbestrol (DES) D. Erythromycin E. Sulfisoxazole
E. SULFISOXAZOLE:
Kernicterus is a disorder caused by high levels of unconjugated bilirubin, a breakdown product of hemoglobin. This neurological disorder is characterized by opisthotonus (a high-pitched cry), abnormal Moro reflex, and abnormal eye movements. The development of kernicterus in an infant can occur when the mother takes sulfonamide antibiotics, such as sulfisoxazole, during pregnancy.
- Acetaminophen is a mild analgesic and antipyretic agent that can be safely taken in during pregnancy.
- Chloramphenicol is a broad-spectrum antibiotic effective against a wide variety of gram-negative, gram-positive, and anaerobic organisms. The use of this antibiotic in infants is associated with a condition referred to as “gray-baby syndrome”. This syndrome is associated with cyanosis, vascular collapse, and elevated drug levels.
- Diethylstilbestrol (DES) is an older agent that is sometimes used in estrogen deficiency states and in the treatment of prostatic carcinoma; its use is contraindicated during pregnancy. DES is known to increase the risk of vaginal and/or cervical cancer in the offspring.
- Erythromycin is a macrolide antibiotic used for the treatment of a variety of infections; the use is this antibiotic during pregnancy is acceptable.
In the case of a drug that follows first-order elimination,
A. the rate of elimination is constant. B. the elimination half-life varies with the dose. C. the volume of distribution varies with the dose. D. the clearance varies with the dose. E. the rate of elimination varies directly with the dose.
E. the rate of elimination varies directly with the dose:
In first-order kinetics, the elimination rate of a drug is directly proportional to its plasma concentration, which in turn is proportional to the dose (choice E). Hence, choice A is incorrect. Drugs that follow first-order elimination also have constant elimination half-lives (choice B). Likewise, volume (choice C) and clearance (choice D) of distribution are pharmacokinetic characteristics of a drug that do not routinely change with dose, although they may vary in terms of disease or dysfunction.
The extent of local anesthetic being absorbed from the injection site is dependent upon all of the following EXCEPT
A. chemical structure of the medication. B. dose of medication administered. C. presence of epinephrine. D. relative potency of the drug. E. vascularity at the injection site.
D. relative potency of the drug:
In general, systemic toxicity of local anesthetics is determined by the rate of drug absorption from the injection site in relation to the drug redistribution and metabolism. The extent of the absorption of any drug from the site of injection, including local anesthetics, is dependent on the pharmacokinetic properties of the drug; such as: the chemical structure of the drug (choice A) (i.e. amide or ester), the dose of the medication administered (choice B) (i.e. as the amount of medication administered increases, so does the extent of drug absorption), the presence of epinephrine (choice C), and the vascularity at the injection site (choice E). The relative potency of a medication (choice D) does not affect the extent of the drug’s ability to be absorbed at the injection site.
A patient has just had two teeth extracted, and you are going to prescribe postoperative analgesics. The patient has a history of gastric ulcers. You should avoid all of the following medications EXCEPT
A. indomethacin. B. aspirin. C. naproxen. D. Tylenol #3. E. diflunisal.
D. Tylenol #3 (acetaminophen with codeine):
has few irritative gastric effects. Aspirin (choice B) is always contraindicated in ulcer patients, as are most of its derivatives, like diflunisal (choice E) (Dolobid). Indomethacin (choice A) is an acetic acid derivative with a side effect of GI bleeding. Naproxen (choice C) (Naprosyn) is a propionic acid derivative with bleeding side effects as well.
Warfarin exerts its anticoagulant properties by inhibiting the production of:
A. cyclooxygenase. B. fibrinogen. C. platelets. D. thromboxane A2. E. vitamin K-dependent clotting factors.
E. vitamin K-dependent clotting factors:
Warfarin is an anticoagulant that exerts its mechanism of action by interfering with the synthesis of the vitamin K-dependent clotting factors (II, VII, IX, X). Its antithrombotic effects are not fully seen until 2 to 5 days (mean of 3 to 4 days) after the first dose. It is indicated for the prophylaxis and treatment of atrial fibrillation with embolism, adjunctive treatment of coronary occlusion, and prophylaxis of systemic embolism (after MI) as well as various other indications.
- Cyclooxygenase is an enzyme that is inhibited by aspirin and the nonsteroidal anti-inflammatory drugs (NSAIDs); its production is not affected by warfarin.
- Fibrinogen is a precursor of fibrin, which is an elastic filamentous protein that promotes coagulation; fibrinogen production is not affected by warfarin. The production of platelets is not decreased in patients taking warfarin therapy.
- Aspirin and the NSAIDs are able to prolong bleeding time by the acetylation of platelet cyclooxygenase, which decreases the synthesis of thromboxane A2. Thromboxane A2, a prostaglandin derivative, is a potent vasoconstrictor and inducer of platelet aggregation.
Which of the following medications used in the treatment of Parkinson disease also possesses antiviral properties?
A. Amantadine B. Bromocriptine C. Carbidopa D. Levodopa E. Selegiline
A. Amantadine is an agent used in the treatment of Parkinson disease as an initial agent or in combination with other anti-Parkinson agents. Amantadine is also used for the symptomatic treatment of influenza A infections because of its antiviral properties.
- Bromocriptine is a dopamine agonist used as an adjunctive agent to levodopa in the treatment of Parkinson disease. It is also used in the short-term management of amenorrhea/galactorrhea or female infertility associated with hyperprolactinemia.
- Carbidopa has no pharmacologic action for the treatment of Parkinson disease; however, it does decrease the metabolism of levodopa in the body.
- Levodopa is the most effective agent available for the treatment of Parkinson disease. It is decarboxylated to dopamine in the brain. Remember, dopamine deficiency is the etiology for Parkinson disease.
- Selegiline is effective for the treatment of Parkinson disease because it inhibits the intracerebral metabolic degradation of dopamine by irreversibly inhibiting monoamine oxidase type B.
The antiarrhythmic effect of which of the following agents mostclosely resembles that of mexiletine and tocainide?
A. Esmolol B. Disopyramide C. Lidocaine D. Quinidine E. Verapamil
C. Lidocaine:
Both mexiletine and tocainide are classified as class IB antiarrhythmic agents that shorten the action potential duration and refractory period and improve the resting potential duration. They produce a modest suppression of sinus node automaticity as well as AV node conduction. Lidocaine is also classified as a class IB antiarrhythmic.
Esmolol is a class II antiarrhythmic agent that exerts its action as an ultra-short acting beta 1-adrenergic blocking agent with cardioselective properties.
Both disopyramide (choice B) and quinidine (choice D) are class IA antiarrhythmics. They depress myocardial excitability, conduction velocity, contractility, and automaticity. They also prolong effective refractory period and block vagal stimulation of the AV node.
Verapamil (choice E) is a calcium channel blocking agent and a class IV antiarrhythmic agent. As an antiarrhythmic, verapamil decreases and slows SA and AV node conduction.
• Class I: Na channel blockers (NCBs) o IA: (ADPQ) depress myocardial excitability, conduction velocity, contractility, automaticity, prolong effective refractory period & block vagal stimulation of AV node ♣ Amiodarone(cordarone) ♣ Disopyramide(norpace) = prolong AP ♣ Procainamide(procan sr): side- SLE ♣ Quinidine(quinidex): side- SLE o IB: (LMT) shorten AP ♣ Lidocaine(xylocaine) ♣ Mexiletine(mexitil) ♣ Tocainide(tonocard) o IC: Flecainide(tambocor), Propafenone(rhythmol) = no AP effect
• Class II: ultra-short acting beta1-adrenergic blocking agents w/ cardioselective properties; increase refractory period, decrease conduction velocity, reduce automaticity o Acetbutolol(sectral) o Esmolol(brevibloc) o Metoprolol(Lopressor): o Propranolol(Inderal)
• Class III: K+ channel blockers (KCBs) o Amiodarone(cordarone), Sotalol(betapace), Ibutilide(corvert), Dofetilide(tikosyn) = increase refractory period, reduce automaticity
• Class IV: CCBs – indirect vasodilators (Diltiazem, Nifedipine, Verapamil), antiarrhythmic agent- decreases & slows SA&AV node conduction
o Verapamil(calan), Diltiazem = increase refractory period, decrease conduction velocity & automaticity
♣ Verapamil: strong negative ionotropic, side- hypotension & dizziness
All of the following drugs may cause theophylline toxicity, EXCEPT:
A. erythromycin. B. ciprofloxacin. C. clarithromycin. D. cimetidine. E. amoxicillin.
E. AMOXICILLIN:
Theophylline is a xanthine derivative that relaxes smooth muscle by direct action. The smooth muscles in the bronchi and pulmonary vessels are particularly affected. This agent also stimulates the respiratory center. Theophylline is commonly used for prophylaxis and symptomatic relief of bronchial asthma. This agent is extensively metabolized by the liver. Therefore, any agent that inhibits liver metabolism would increase the blood level of theophylline in the body, which would potentiate the effects of theophylline as well as its adverse effects.
- Clarithromycin and erythromycin are macrolide antibiotics commonly used in the treatment of upper respiratory infections, skin, and skin structure infections. They decrease theophylline clearance by inhibiting cytochrome P450 3A3. Therefore, they are likely to potentiate the toxic effects of theophylline.
- Ciprofloxacin may result in a 50% to 60% increase in serum theophylline levels. It decreases theophylline clearance by inhibiting cytochrome P450 1A2. However, the newer fluoroquinolones (moxifloxacin, gemifloxacin, gatifloxacin, levofloxacin, and trovafloxacin) do not interfere with theophylline metabolism.
- Cimetidine decreases theophylline clearance by inhibiting cytochrome P450 1A2. Therefore, it is likely to potentiate the toxic effects of theophylline. Doxycycline and amoxicillins do not have any reported interaction with theophylline
If a patient with high cholesterol needed an antihypertensive agent, which of the following medications would most likely worsen the dyslipidemia?
A. Captopril B. Verapamil C. Clonidine D. Metoprolol E. Terazosin
D. METOPROLOL:
Metoprolol is a beta-adrenergic blocking agent that is known to cause dyslipidemias and worsen coexisting dyslipidemias. All of the other medications are not associated with the development of dyslipidemias.
- Captopril, an ACE inhibitor, and verapamil, a calcium-channel blocker, are both “first-line agents” used to treat essential hypertension; they are not associated with the development of dyslipidemias.
- Both clonidine, a centrally acting alpha-receptor agonist, and terazosin, a peripherally acting alpha-receptor-blocking agent, can be used to treat hypertension. However, due to their side effect profiles, these agents are generally used in patients unresponsive to other antihypertensive therapies.
Which condition is NOT an indication for antibiotic prophylaxis for subacute bacterial endocarditis?
A. Hypertrophic cardiomyopathy B. Angina pectoris C. Tetralogy of Fallot D. Prosthetic cardiac valves
B. Angina pectoris:
There are many congenital and acquired conditions that require antibiotic premedication, including hypertrophic cardiomyopathy, tetralogy of Fallot, and prosthetic cardiac valves.
Those that DO NOT require antibiotic premedication include angina pectoris, cardiac bypass surgery, cardiac pacemakers, and previous myocardial infarction.
If a 14-year-old female develops arthropathy shortly after receiving antibiotic therapy, she most likely received treatment with which of the following?
A. Cefaclor B. Chloramphenicol C. Ciprofloxacin D. Procainamide E. Sulfamethoxazole/trimethoprim
C. CIPROFLOXACIN:
Ciprofloxacin is a fluoroquinolone antibiotic indicated for the treatment of a wide variety of infections caused by both gram-negative and gram-positive organisms. This agent and other fluoroquinolone antibiotics are associated with the development of signs and symptoms of arthropathy when administered to children under the age of 18.
- Cefaclor is a second-generation cephalosporin used in the treatment of a variety of upper and lower respiratory infections. This antibiotic been associated with the development of a serum-like sickness, especially when administered to infants and young adults. The reaction most commonly seen with the agent is the development of erythema multiforme with rash as well as arthralgias.
- Chloramphenicol is a broad-spectrum antibiotic used in the treatment of many different infections. This agent is known to cause the disorder called “gray baby syndrome” when given to infants.
- Procainamide is a Class 1A antiarrhythmic (not an antibiotic) used in the prevention of paroxysmal atrial fibrillation and tachycardia and is associated with the development of systemic lupus erythematous (SLE), which is an inflammatory autoimmune disorder that can affect multiple organ systems. Characteristic signs and symptoms of this disease can include fever, anorexia, malaise, malar rash (butterfly rash), photosensitivity, arthritis, serositis, and various hematologic and immunologic abnormalities. Other medications associated with the development of SLE include procainamide, hydralazine, chlorpromazine, isoniazid, methyldopa, and quinidine.
- Sulfamethoxazole/trimethoprim is a “sulfa” antibiotic primarily used in the treatment of urinary tract infections. This agent has been associated with the development of blood dyscrasias, especially in the elderly and in those with some degree of immunosuppression.
Which antibiotic is NOT given orally?
A. Amoxicillin B. Streptomycin C. Clarithromycin D. Clindamycin E. Metronidazole
B. STREPTOMYCIN:
Streptomycin is an inhibitor of the 30S subunit of the bacterial ribosome and is in the aminoglycoside family of antibiotics with neomycin, gentamicin, and amikacin. It is effective only for aerobic infections and is sometimes used as an antimycobacterial. It is administered intravenously or intramuscularly, and it is sometimes used in combination with beta-lactam-type antibiotics.
Amoxicillin, clarithromycin, clindamycin, and metronidazole can all be administered.
At clinically relevant doses, the lipid-lowering potential is greatest for which of the following?
A. Atorvastatin B. Simvastatin C. Lovastatin D. Pravastatin E. Fluvastatin
A. ATORVASTATIN:
At clinically relevant doses, the lipid-lowering potential is as follows (from greatest to least potential):
- Atorvastatin
- Simvastatin
- Lovastatin
- Pravastatin
- Fluvastatin
All of these agents are reversible, competitive inhibitors of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. This enzyme is the rate-limiting enzyme in cholesterol biosynthesis. HMG-CoA reductase catalyzes the conversion of HMG-CoA to mevalonate, a cholesterol precursor, in the liver. Inhibition of the enzyme leads to a decrease in the serum LDL level.
A patient with a “sulfa” allergy would most likely have an allergic reaction if prescribed which of the following medications?
A. Acetaminophen B. Aspirin C. Hydrochlorothiazide D. Ketorolac E. Terazosin
C. HCTZ:
The patient has a past medical history significant for “sulfa” allergies; therefore, he should not be prescribed any medications that contain sulfur or chemically related compounds, such as thiazide diuretics. Because hydrochlorothiazide is a thiazide diuretic, the patient is most likely to have an allergic reaction to this medication. All of the other answer choices can be safely administered to this patient.
- Acetaminophen possesses analgesic and antipyretic effects with no anti-inflammatory properties.
- Aspirin is a salicylate with analgesic, antipyretic, and anti-inflammatory properties.
- Ketorolac is a nonsteroidal anti-inflammatory drug (NSAID) with analgesic, antipyretic, and anti-inflammatory properties.
- Terazosin is an alpha-1-receptor blocking agent used in the treatment of hypertension and prostatic hypertrophy. This agent is most commonly associated with the development of hypotension.
Enhancement of the effects of bradykinin is most likely to occur with drugs such as
A. clonidine. B. diazoxide. C. lisinopril. D. losartan. E. propranolol.
C. LISINOPRIL:
ACE inhibitors (e.g., lisinopril) prevent the conversion of angiotensin I to angiotensin II, and lower blood pressure by decreasing the formation of aldosterone and reducing vasoconstrictive action of Angiotensin II at AT-1 receptors. ACE inhibitors also inhibit the metabolism of bradykinin, and this leads to additional hypotensive effects because bradykinin is an endogenous vasodilator.
- Clonidine lowers blood pressure and heart rate by relaxing the arteries and increasing the blood supply to the heart.
- Diazoxide reduces peripheral vascular resistance and blood pressure as a result of a direct vasodilatory effect on smooth muscles in peripheral arterioles.
- Losartan and propranolol potentiates the effect of Bradykinin; however, this effect is most likely to occur with ACE inhibitors.
A 72-year-old man with heart failure is prescribed an ACE inhibitor. This agent is most likely to cause which of the following electrolyte abnormalities?
A. Hyperkalemia B. Hypernatremia C. Hyperuricemia D. Hypokalemia E. Hyponatremia
A. HYPERKALEMIA:
The angiotensin-converting enzyme (ACE) inhibitors are indicated for the treatment of hypertension, heart failure, myocardial infarction, and diabetic nephropathy. With respect to heart failure, ACE inhibitors improve hemodynamic measures and congestive symptoms, reduce cardiovascular events and hospitalization, and improve survival (i.e., decrease morbidity and mortality). Before starting therapy, it is recommended that the patient’s electrolyte status be monitored because the ACE inhibitors are known to cause hyperkalemia. In fact, these agents are contraindicated if the patient’s serum potassium levels exceed 5.5 mmol/L.
Hydrolysis of lidocaine hydrochloride into ions is best achieved at pHs that are
A. highly acidic. B. slightly acidic. C. neutral. D. basic.
B. Slightly acidic:
Local anesthetics must be ionized in order to function inside the neuron, but unionized in order to pass through the fatty cell membrane of the neuron. Anesthetics are first treated with hydrochloric acid to ionize them and to help increase storage life of both anesthetic and vasoconstrictor. When the anesthetic is injected into tissue, tissue buffers neutralize the ions and a free base is formed. This unionized free base freely enters the cell membrane. Within the cell, the slightly acidic environment inside the neuron causes ionization once again into a charged form, which attaches to sodium channels and blocks the entrance of sodium ions, thus preventing action potentials and nerve impulses.
Which of the following agents is most likely to cause tachycardia when used in the treatment of angina?
A. Diltiazem B. Metoprolol C. Nifedipine D. Propranolol E. Verapamil
C. NIFEDIPINE:
Angina is a condition characterized by a “pain in the chest” secondary to a decreased amount of oxygen supply to the myocardial tissue. Nitrates, beta-receptor blockers, and calcium channel blockers are used in the treatment of angina. Nifedipine, a calcium channel antagonist, is most likely to cause tachycardia when used in the treatment of angina. Inhibition of calcium in arterial smooth muscle is associated with decreased arterial tone and decreased arterial pressure. The reduction in arterial pressure results in reflex tachycardia.
- However, other calcium channel blockers, such as diltiazem and verapamil, also decrease intracardiac contractility. Verapamil and diltiazem have more pronounced effects on calcium channels of the myocytes as well as of the cardiac pacemaker and atrioventricular conduction cells, leading to a negative inotropic effect and reduction of heart rate. Therefore, these agents are less likely to cause tachycardia.
- Both metoprolol and propranolol are beta-receptor antagonists. These agents are successfully used in the treatment of angina since they decrease heart rate, hence decreasing myocardial oxygen demand. In other words, these agents are more likely to cause bradycardia, not tachycardia.
- The interaction of phenytoin (anticonvulsant), cyclosporine (immunosuppressant), and nifedipine (calcium channel blocker) with epithelial keratinocytes, fibroblasts, and/or collagen can lead to gingival hyperplasia in susceptible individuals. Phenytoin causes gingival hyperplasia by its interaction with a subpopulation of sensitive fibroblasts.
Potential risk factors for drug-induced gingival hyperplasia include the following:
Poor oral hygiene Periodontal disease Periodontal pocket depth Gingival inflammation Degree of dental plaque Duration and dose of medication
On the basis of its ability to alter the electrolyte levels in the body, hydrochlorothiazide could theoretically be used in the treatment of which of the following?
A. Hypocalcemia B. Hypochloremia C. Hypokalemia D. Hypomagnesemia E. Hyponatremia
A. HYPOCALCEMIA:
Thiazide diuretics such as hydrochlorothiazide are sulfonamide derivatives that promote diuresis by inhibiting reabsorption of sodium chloride primarily in the early distal tubule. Thiazide diuretics decrease the excretion of calcium; therefore, these agents could theoretically be used in the treatment of hypocalcemia. Because these drugs increase the renal elimination of chloride, potassium, magnesium, and sodium, they promote the development of hypochloremia, hypokalemia, hypomagnesemia, and hyponatremia, respectively.
Which antibiotic does NOT affect cell walls?
A. Methicillin B. Cephalexin C. Erythromycin D. Vancomycin
C. ERYTHROMYCIN:
Erythromycin acts on the 50S subunit of bacterial ribosomes. All penicillins, such as methicillin, and cephalosporins, such as cephalexin, prevent NAG-NAM cross-linkages in bacterial cell walls. Both vancomycin and bacitracin are cell-wall inhibitors, but neither works by inhibiting NAG-NAM cross-linkages.
Which antiviral is useful in treating cytomegalovirus in AIDS patients?
A. Sulfamethoxazole/trimethoprim B. Acyclovir C. Ganciclovir D. Zidovudine E. Clotrimazole
C. GANCICLOVIR:
Ganciclovir is effective against many herpes family viruses, including herpes simplex virus 1 (HSV-1), HSV-2, Epstein-Barr virus (EBV), varicella-zoster virus (VZV), and cytomegalovirus (CMV). In particular, it is used to treat HIV-associated CMV retinitis.
- A major difference from acyclovir is that acyclovir is not effective against CMV.
- Sulfamethoxazole/trimethoprim inhibits folic acid synthesis in bacteria and is used to treat Pneumocystis carinii (now known as P. jiroveci) pneumonia.
- Clotrimazole is an imidazole antifungal used to treat candidiasis.
- Zidovudine, also known as AZT, is a reverse transcriptase inhibitor used to treat HIV infection.
Which of the following antibiotics is MOST likely to potentiate the effects of theophylline?
A. Ampicillin B. Cefpodoxime C. Chloramphenicol D. Erythromycin E. Tetracycline
D. ERYTHROMYCIN:
Theophylline is a xanthine derivative that relaxes smooth muscle by direct action. The smooth muscles in the bronchi and pulmonary vessels are particularly affected. This agent also stimulates the respiratory center. Theophylline is commonly used for prophylaxis and symptomatic relief of bronchial asthma. This agent is extensively metabolized by the liver. Therefore, any agent that inhibits liver metabolism would increase the blood level of theophylline, which would potentiate the effects of theophylline as well as its adverse effects. Erythromycin is a macrolide antibiotic commonly used in the treatment of upper respiratory, skin, and skin structure infections. This agent is a hepatic microsomal enzyme inhibitor. Therefore, erythromycin is likely to potentiate the effects of theophylline.
The other agents generally do not interact with theophylline.
Ampicillin is a “penicillin” antibiotic used to treat a variety of infections caused by many different organisms.
Cefpodoxime is a third-generation cephalosporin used commonly to treat otitis media as well as upper and lower respiratory infections.
Chloramphenicol is an anti-infective commonly used to treat severe infections when less toxic agents are not indicated.
Tetracycline is a “tetracycline” antibiotic commonly used in the treatment of acne and various sexually transmitted diseases.
Which antibiotic is associated with aplastic anemia as a side effect?
A. Metronidazole B. Chloramphenicol C. Bacitracin D. Clindamycin E. Sulfamethoxazole
B. CHLORAMPHENICOL:
Three significant side effects are associated with chloramphenicol.
- dose-dependent pancytopenia (bone marrow inhibition).
- non-dose-dependent effect on bone marrow, which can be fatal (aplastic anemia).
- “gray baby syndrome,” a liver failure in fetuses that may occur when the pregnant mother takes chloramphenicol.
It is unlikely that metronidazole, bacitracin, clindamycin, or sulfamethoxazole will cause aplastic anemia, although each drug may have other possible side effects.
A 58-year-old woman with asthma who needs to be prescribed a beta-blocker for the treatment of hypertension should receive which of the following?
A. Metoprolol B. Nadolol C. Sotalol D. Propranolol E. Timolol
A. METOPROLOL:
One of the primary methods of treatment for an asthmatic patient is use of a beta-2-receptor agonist such as albuterol. When this agent is used, one will see bronchodilation. However, when an agent with beta-2-receptor blocking properties is prescribed, the patient will experience worsening of the asthma signs and symptoms secondary to bronchoconstriction. For this reason, beta-receptor-blocking agents should be avoided in patients with asthma.
However, if a patient with asthma needs to be prescribed a beta-blocker for the treatment of hypertension, this patient should be prescribed a beta-1-selective blocking agent, such as Metoprolol or Atenolol.
Because all the other agents, including nadolol, sotalol, propranolol, and timolol are all nonselective beta-blocking agents, they should not be used in this patient.
Which of the following drugs is used to treat drooling of saliva?
A. Amitriptyline B. Buspirone C. Clozapine D. Haloperidol E. Pilocarpine
A. AMITRIPTYLINE:
Amitriptyline is a tricyclic antidepressant commonly used in the treatment of the depressive periods for bipolar patients; it has no effect on the manic phase of bipolar disorder. When amitriptyline is taken orally, it blocks acetylcholine receptors in the salivary glands and thereby reduces drooling.
- Buspirone is an anxiolytic used in the treatment of mild anxiety disorders and would not be effective in the treatment of mania. Buspirone therapy may cause arthralgia, muscle cramps or stiffness, salivation, facial edema, and dysgeusia.
- Clozapine is indicated only in the management of severely ill schizophrenic patients who have failed to respond to other neuroleptic agents. Sialorrhea is a very disturbing adverse effect that develops in the early period of clozapine treatment. Excess saliva causes pooling in the oral cavity, and this leads to overflow of saliva from mouth.
- Haloperidol is an antipsychotic drug used to treat psychotic disorders like schizophrenia, to control motor (movement) and verbal (for example, Tourette syndrome) tics and is used to treat severe behavior problems in children. It causes drooling.
- Pilocarpine is a cholinergic agonist that causes drooling of saliva. It is used to treat dry mouth.
The rate and extent of ophthalmic drug absorption is dependent upon all of the following, EXCEPT the:
A. amount of drug binding to the proteins on the surface of the eye. B. number of drops administered to the eye. C. rate and extent of nasolacrimal drainage. D. total amount of time that the drug remains in the cul-de-sac of the eye. E. viscosity of the ophthalmic preparation.
B. number of drops administered to the eye:
The eye is one of the most delicate organs found within the human body. Therefore, the formulations used in the treatment of ophthalmic infections must be designed to ensure that minimal irritation occurs while maintaining clinical efficacy. Furthermore, proper treatment of ophthalmic infections is essential to ensure that damage does not occur to the eye. After the topical application of a drug to the eye, the rate and extent of ophthalmic drug absorption is dependent upon all of the following: (1) the amount of drug binding to the proteins on the surface of the eye (this concept is very important because only unbound drugs can be absorbed and/or exert their clinical effect); (2) the rate and extent of nasolacrimal drainage (as the amount of nasolacrimal drainage increases, the amount of drug absorption decreases); and (3) the total amount of time that the drug remains in the cul-de-sac of the eye (as the time increases, so does the potential for drug absorption). The time that the drug remains in contact with the eye can be increased by increasing the viscosity of the ophthalmic preparation. The number of drops administered to the eye has no effect on the rate and extent of ophthalmic drug absorption because the eye can only hold less than 50% of one drop. Therefore, if two or three drops are administered, the remainder will be discarded.
A 56-year-old man with hypertension who suddenly develops angioedema was MOST likely receiving which of the following?
A. Atenolol B. Captopril C. Indapamide D. Hydrochlorothiazide E. Verapamil
B. CAPTOPRIL:
Angioedema is a well-demarcated localized edema involving the deeper layers of the skin, including the subcutaneous tissue. This condition is seen with the ACE inhibitors, particularly:
- captopril
- enalapril
- lisinopril.
Atenolol is a beta-1-selective receptor-blocking agent that is associated with the development of bradycardia, dizziness, and impotence in men.
Indapamide and hydrochlorothiazide are thiazide diuretics known to cause glucose intolerance in diabetics, electrolyte abnormalities, and photosensitivity.
Verapamil is a calcium-channel blocker with strong negative inotropic effects and can cause hypotension and dizziness.
Local anesthetic BEST enters the neuron when the anesthetic solution is:
A. very acidic. B. slightly acidic. C. neutral. D. slightly basic.
C. NEUTRAL:
Prior to injection, the anesthetic solution in a carpule is in a slightly acidic and ionized form. When the solution is injected into the tissue, the slightly alkaline tissue fluids neutralize the anesthetic to the free base form. The alkalization of the anesthetic to the nonionized form improves the ability of the drug to enter into the neuron cell membrane. Once it is inside the neuron, it re-ionizes and attaches to the sodium channels to prevent sodium influx.
An individual in a developing country who is diagnosed with beriberi is deficient in which of the following?
A. Ascorbic acid B. Vitamin A C. Vitamin B1 D. Vitamin B3 E. Vitamin B12
C. VitB1:
Thiamin or vitamin B1 deficiency can result in the development of beriberi, which is associated with anorexia, muscle cramps, paresthesias, and high output heart failure as well as sensory and motor nerve impairment.
A deficiency of vitamin C or ascorbic acid is associated with the development of scurvy, a condition associated with malaise, weakness, perifollicular hemorrhages, bleeding gums, and impaired wound healing.
Deficiencies of vitamin A often result in the development of nyctalopia or night blindness.
Niacin or vitamin B3 deficiency is associated with the development of a condition known as pellagra. The classic triad of symptoms seen with pellagra is dermatitis, diarrhea, and dementia.
The hallmark of cyanocobalamin or vitamin B12 deficiency is pernicious anemia. This megaloblastic anemia may be severe, with a hematocrit as low as 10%. Megaloblastic anemia is also associated with changes in mucosal cells, leading to glossitis, as well as various other gastrointestinal disturbances, such as anorexia and diarrhea.
Opioids can be used to treat all of the following conditions EXCEPT
A. cough. B. diarrhea. C. acute psychiatric instability. D. pain. E. pre-anesthesia medication.
C. Acute psychiatric instability:
Opioid analgesics, such as morphine, mimic endogenous endorphins and enkephalins in the CNS at opiate receptors. They work by increasing the pain threshold and raising pain tolerance. Opioids are effective in the treatment of many different types of pain. Opioids also work centrally to inhibit the cough reflex. Diphenoxylate is an opioid commonly used in the treatment of diarrhea. One of the major side effects of opioids is constipation. Most opioids could be used to treat diarrhea; however, due to their side effect profile, only diphenoxylate is used in the treatment of diarrhea. Opioids are primarily used in the treatment of pain and can be used to decrease the pain and anxiety associated with surgery or trauma. They can be effectively used as a preanesthetic medication. Furthermore, opioids often permit a reduction in the amount of general anesthetic required for surgical anesthesia.
Absolute contraindications to opioids include:
- severe respiratory instability
- acute psychiatric instability or uncontrolled suicide risk.
Which of the following agents used in the treatment of gastric ulceration is a potent hepatic enzyme inhibitor?
A. Cimetidine B. Famotidine C. Nizatidine D. Omeprazole E. Ranitidine
A. CIMETIDINE:
Cimetidine is an H2-receptor antagonist indicated for the short-term and maintenance treatment of duodenal and gastric ulceration as well as for gastroesophageal reflux disease (GERD). One of the primary disadvantages of using this agent instead of the other H2-receptor antagonists, such as famotidine, nizatidine, and ranitidine, is that this agent is a relatively potent hepatic enzyme inhibitor. Therefore, the potential for drug interactions with other medications metabolized by the liver exists. The other H2-receptor antagonists are not potent hepatic enzyme inhibitors. Omeprazole is a gastric acid proton-pump inhibitor indicated for the short-term and maintenance treatment of duodenal and gastric ulceration as well as GERD; it does not affect the hepatic enzymes.
Prior to a tooth extraction, a woman in her third trimester of pregnancy needs a prophylactic antibiotic because of prosthetic valves. If this patient has a past medical history significant for an anaphylactic reaction to penicillin, the most appropriate medication for this patient would be which of the following?
A. Dicloxacillin B. Azithromycin C. Ciprofloxacin D. Trimethoprim/sulfamethoxazole E. Tetracycline
B. AZITHROMYCIN:
The Food and Drug Administration (FDA) has established a set of pregnancy categories to determine the rational use of any medication that requires a risk versus benefit assessment. Regardless of the designated Pregnancy Category or presumed safety, no medication/drug should be administered during pregnancy unless it is clearly needed, and the potential benefits outweigh the potential hazards to the fetus. Azithromycin is classified as Pregnancy Category B. You do not need to know the pregnancy category of all drugs.
What is the initial oral clindamycin dosage and timing for antibiotic prophylaxis?
A. 2 g 30 minutes to 1 hour before B. 1 g 1 hour before C. 600 mg 30 minutes to 1 hour before D. 600 mg 1 to 2 hours before E. 300 mg 30 minutes to 1 hour before
C. 600 mg 30 minutes to 1 hour before:
Clindamycin is the primary oral antibiotic substitute for amoxicillin in the penicillin-allergic patient. Others include azithromycin, clarithromycin, cefadroxil, and cephalexin. Clindamycin is given 600 mg 30 minutes to 1 hour before the procedure. The children’s dose is 20 mg/kg.
In terms of the ability of drugs such as digoxin to increase cardiac contractility, their primary action on cardiac cells is
A. the activation of adenylyl cyclase. B. inactivation of Na+ channels. C. activation of the slow Ca2+ channel. D. inhibition of Na+/K+/ATPase. E. activation of the Na+/Cl- cotransport.
D. inhibition of Na+/K+/ATPase:
Cardiac glycosides increase contractility by inhibiting the Na+/K+/ATPase pump, causing an increase in intracellular Na. This, in turn, increases intracellular Ca by slowing down Na+/Ca2+ exchange. The increase in intracellular Ca2+ leads to its binding to the troponin-tropomyosin complex, causing an allosteric change and facilitating the interaction. Digoxin may indirectly inhibit an increase of adenylyl cyclase in other tissues. Digoxin activates sarcoplasmic reticulum Ca(2+) release channels – a possible role in cardiac inotropy.
A 22-year-old woman who was just diagnosed with chlamydial conjunctivitis would be MOST appropriately treated with which of the following?
A. Intramuscular ceftriaxone B. Oral tetracycline C. Vancomycin D. Topical ketorolac E. Topical naphazoline
B. ORAL TETRACYCLINE:
Chlamydial keratoconjunctivitis is a major cause of blindness worldwide. This condition is associated with recurrent episodes of infection in children and is often manifested as a bilateral follicular conjunctivitis. The diagnosis is made using the Giemsa-stained conjunctival scrapings. The most common treatment measures include either oral tetracycline or oral erythromycin.
- Intramuscular ceftriaxone is commonly used for the treatment of gonococcal conjunctivitis.
- Vancomycin is most commonly used for the treatment of pseudomembranous colitis.
- Topical ketorolac is commonly used for the treatment of ocular inflammation.
- Topical naphazoline is most commonly used for the treatment of symptomatic allergic conjunctivitis.
If a 42-year-old male was recently diagnosed with trigeminal neuralgia, which of the following agents would most effectively treat his condition chronically?
A. Alprazolam B. Buspirone C. Carbamazepine D. Cefixime E. Neostigmine
C. CARBAMAZEPINE:
Trigeminal neuralgia, otherwise known as tic douloureux, is a condition characterized by excruciating paroxysms of pain in the lips, gums, chin, and cheek. The intense pain typically lasts for no more than a minute or two; however, the pain can be so intense that the patient winces. Tic douloureux is the most striking disorder of trigeminal nerve function. The most effective treatment for trigeminal neuralgia is the antiepileptic agent carbamazepine. In addition to carbamazepine, phenytoin can also be used to effectively treat trigeminal neuralgia.
- Alprazolam, a short-acting benzodiazepine, is indicated for the management of a variety of anxiety disorders.
- Buspirone is a non-sedating anxiolytic primarily used in the management of anxiety disorders and for short-term treatment of generalized anxiety.
- Cefixime is a third-generation cephalosporin antibiotic primarily used in the treatment of upper respiratory infections as well as ear infections.
- Neostigmine is a reversible cholinesterase inhibitor used in the prevention and treatment of postoperative abdominal distention and urinary retention. It is also used to reverse the effects of nondepolarizing muscle relaxants, such as tubocurarine.
The cardiac medication digitalis acts on the heart by
A. increasing the force of contraction. B. increasing the refractory period of the atrial muscle. C. increasing the refractory period of the ventricular muscle. D. increasing the rate of conduction of impulses to the muscle. E. decreasing the force of contraction.
A. increasing the force of contraction:
In therapeutic doses, digitalis affects the cardiac muscle. The principal effect of digitalis is its positive inotropic action or, in other words, it increases the force of myocardial contraction. This will increase cardiac output and decrease venous pressure and blood volume. In addition, it will cause diuresis and relief of edema. Digitalis decreases the refractory period of the atrial myocardium through a direct and indirect effect (vagotonic and vagomimetic). It also decreases the refractory period of the ventricular myocardium. Finally, digitalis can depress the rate of impulse formation and propagation.
How much lidocaine is contained in five carpules (1:8 ml each) of 2% lidocaine with epinephrine 1:100,000?
A. 1.8 mg B. 36 mg C. 90 mg D. 180 mg E. 360 mg
D. 180mg:
2 percent lidocaine contains 2 grams lidocaine per each 100 ml of solution. 2 grams equals 2,000 mg. So, we have 2,000 mg per 100 ml of anesthetic solution. Reducing by 100, we get 20 mg lidocaine for each 1 ml of solution. Multiplying by 1.8 for a standard carpule, we get 36 mg lidocaine per 1.8 ml of solution. 5 carpules should have 5 times 36 mg or 180 mg of lidocaine.
Which of the following compounds has the most activity against gram-negative organisms?
A. Cefaclor B. Cephalexin C. Vancomycin D. Metronidazole E. Cefixime
E. CEFIXIME:
Cefixime is a third-generation cephalosporin commonly used to treat various infections caused by gram-negative organisms. A general rule to remember about cephalosporins is: when progressing from first generation to third generation, the gram-negative activity is increased and the gram-positive activity is decreased. Therefore, first-generation cephalosporins have the most activity against gram-positive organisms and third-generation cephalosporins have the greatest activity against gram-negative activity.
- 1st gen: Cephalexin; g(+)
- 2nd gen: Cefaclor
- Vancomycin: is an antibiotic with excellent g(+) activity.
- Metronidazole is an antibiotic with excellent anaerobic bacterial coverage.
What is the proper dosage and timing for oral cephalexin prophylaxis in adults?
A. 1.0 gram, 30 minutes to 1 hour before procedure B. 2.0 gram, 30 minutes to 1 hour before procedure C. 600 mg, 1 hour before procedure D. 500 mg, 30 minutes to 1 hour before procedure E. 20 mg/kg, 1 hour before procedure
B. 2.0 gram, 30 minutes to 1 hour before procedure:
Oral cephalexin and cefadroxil doses are the same as those for amoxicillin, 2.0 gram 30 minutes to 1 hour before procedure, children 50 mg/kg. The IM and IV cefazolin dosage is 1.0 gram 30 minutes to 1 hour before procedure.
Which of the following narcotic analgesics has the highest relative strength?
A. Oxycodone B. Hydrocodone C. Codeine D. Propoxyphene E. Naloxone
A. OXYCODONE:
Opioid analgesics are commonly used in combination with acetaminophen for the treatment of moderate to severe pain. The majority of compounds related to morphine can cause: respiratory depression, euphoria, drowsiness, nausea, vomiting, peripheral vasodilation, decreased peripheral resistance, orthostatic hypotension, inhibition of peristalsis, and urinary retention. The potency (relative strength) of each compound is related to the number of milligrams of each substance needed to produce the desired and adverse effects. For example, 5 milligrams of oxycodone will produce more analgesia, euphoria, and other side effects than 5 milligrams of hydrocodone. In relation to the narcotic analgesics listed in this question, the relative strengths are as follows:
- oxycodone
- hydrocodone
- codeine
- propoxyphene
Narcotic antagonists like naloxone block the opioid receptors and inhibit the desired and adverse effects. Naloxone has minimal analgesic properties.
A 74-year-old, penicillin-allergic man is prescribed erythromycin following a tooth extraction. If the patient’s warfarin level increases, leading to an increased INR, this type of drug interaction between warfarin and erythromycin can best be described as which of the following?
A. Pharmacodynamic B. Pharmaceutical C. Pharmacokinetic D. Pharmacoeconomic E. Pharmacoepidemiologic
C. PHARMACOKINETIC:
There are three primary types of drug interactions: pharmacokinetic, pharmacodynamic, and pharmaceutical.
- pharmacokinetic interaction: one drug alters the concentration of another in the blood secondarily by affecting the absorption, distribution, metabolism, or excretion of the other medication. In this case, the patient is receiving erythromycin, which is a hepatic enzyme inhibitor. This agent decreases the metabolism of warfarin, leading to an increased warfarin blood level.
- pharmacodynamic interaction: one drug alters the action of another drug without affecting the blood levels of the other medication. For example, if alcohol is ingested with a benzodiazepine, there will be a dramatic increase in the amount of drowsiness experienced by the patient.
- pharmaceutical interaction, there is a chemical or physical interaction between two or more drugs before they enter the body. For example, when iron and tetracycline are taken together, these agents “bind” in the intestinal tract, which prevents the absorption of both medications.
Which of the following cephalosporins is LEAST likely to cross the blood-brain barrier?
A. Cefazolin B. Cefixime C. Cefpodoxime D. Ceftazidime E. Ceftibuten
A. CEFAZOLIN:
As a “subclass” of antibiotics, the third-generation cephalosporins are able to effectively penetrate the blood-brain barrier. However, the first- and second-generation cephalosporins are for the most part unable to penetrate into the CNS.
- 1st gen: Cefazolin
- 3rd gen: Cefixime, Cefpodoxime, Ceftazidime, Ceftibuten
A 62-year-old male presents with the signs and symptoms of Parkinson disease. The patient states that prior to this acute onset of symptoms, his Parkinson disease was well controlled with medications. If the patient states that his signs and symptoms began shortly after starting a new “stomach” medication, he was most likely receiving:
A. cimetidine. B. nizatidine. C. metoclopramide. D. lansoprazole. E. sucralfate.
C. METOCLOPRAMIDE:
The patient is presenting with signs and symptoms of Parkinson disease, specifically an exacerbation of his condition secondary to the administration of metoclopramide. The mechanism of this side effect is related to metoclopramide’s antagonism of the dopamine receptors. Metoclopramide is a prokinetic agent indicated for the treatment of gastroesophageal reflux disease (GERD) and diabetic gastroparesis. It is important to note that drug-induced Parkinson disease is indistinguishable from idiopathic Parkinsonism and is usually reversible in a few weeks upon discontinuation of medication. However, the severity and duration of the signs and symptoms from the drug-induced Parkinson disease are often more pronounced when they occur in patients with established Parkinson disease. In addition to the development of Parkinson-like symptoms, metoclopramide is also associated with the development of extrapyramidal symptoms and tardive dyskinesia.
- Both Cimetidine and Nizatidine are H2-receptor antagonists used in the treatment of GERD and gastric ulcers; these agents are generally well tolerated with very little incidence of side effects.
- Lansoprazole is a proton-pump inhibitor indicated for the treatment of gastric ulcerations and GERD; this agent is generally well tolerated with very little incidence of side effects.
- Sucralfate is a basic aluminum salt that forms an ulcer adherent complex at the site of the ulcer and is indicated for the treatment of duodenal ulcers. Constipation is the most common side effect.
With respect to the penicillin antibacterial class of antibiotics, which which of the following statements is NOT true?
A. Central nervous system penetration is best when inflammation is present. B. Inadequate penicillin blood levels can produce bacteriostatic effects. C. Penicillins inhibit the biosynthesis of cell wall mucopeptides. D. Penicillins possess narrow gram-negative and gram-positive bacterial coverage. E. There is a small chance that patients allergic to penicillin will be allergic to a cephalosporin.
D. Penicillins possess narrow gram-negative and gram-positive bacterial coverage:
With respect to the penicillin antibacterial class of antibiotics, these agents possess narrow gram-negative and broad gram-positive bacterial coverage. Central nervous system penetration is best when inflammation is present, which is particularly important with treating a patient with meningitis. Although these agents are bactericidal antibiotics at established blood levels, inadequate penicillin blood levels can produce bacteriostatic effects. With respect to their mechanism of action, penicillins inhibit the biosynthesis of cell wall mucopeptide. There is a small chance that a patient allergic to penicillin will be allergic to a cephalosporin.
The use of tubocurarine is NOT recommended in patients taking which of the following medications?
A. Aspirin B. Gentamicin C. Indomethacin D. Oxycodone E. Penicillin
B. Gentamicin:
Tubocurarine is a non-depolarizing skeletal muscle relaxant used to induce skeletal muscle relaxation and as an adjunct to general anesthesia. Aminoglycoside antibiotics, such as gentamicin and amikacin, may produce neuromuscular blockade, which enhances the blockade produced by skeletal muscle relaxants, like tubocurarine. The danger of enhancing tubocurarine’s effects is that the severity of respiratory depression associated with this agent may be substantially increased. The other agents may be used safely with tubocurarine.
- Aspirin is a salicylate analgesic commonly used in the treatment of mild to moderate pain.
- Indomethacin is a non-steroidal anti-inflammatory drug (NSAID) used for the treatment of pain caused by inflammation. Indomethacin is one of the strongest NSAIDs available.
- Oxycodone is a narcotic analgesic commonly used in the treatment of moderate to severe pain.
- Penicillin is an antibiotic used in the treatment of infections caused by susceptible bacterial strains of streptococci, pneumococci and staphylococci.
