PHARMACOLOGY Sample Questions 1 Flashcards
Which of the following is a local anesthetic subject to inactivation by plasma esterases? a. Procaine b. Lidocaine c. Prilocaine d. Mepivacaine e. Bupivacaine
A
Procaine differs from lidocaine in that
a. Procaine is a p-aminobenzoic acid ester and lidocaine is not
b. Lidocaine is a meta-aminobenzoic acid ester and procaine is not
c. The duration of action of procaine is longer than that of an equal total dose of lidocaine
d. Procaine hydrochloride is metabolized into diethylaminoethanol
and benzoic acid
A
Which of the following local anesthetics would be expected to produce a sensitization reaction in a patient allergic to lidocaine? a. Mepivacaine b. Tetracaine c. Procaine d. Prilocaine e. Dibucaine i. (a), (b) and (c) ii. (a), (d) and (e) iii. (b) and (c) only iv. (b), (c) and (d) v. (b), (d) and (e)
ii
The hydrolysis of procaine occurs mainly in the
a. Liver
b. Lungs
c. Plasma
d. Muscles
e. Kidneys
C
Which of the following is local anesthetic subject to inactivation by plasma esterases?
a. Lidocaine
b. Prilocaine
c. Tetracaine
d. Mepivacaine
e. Bupivacaine
C
The activity of procaine is terminated by
a. Elimination by the kidney
b. Storage in adipose tissue
c. Metabolism in the liver only
d. Metabolism in the liver and by pseudocholinesterase in the
plasma
D
All of the following factors are significant determinants of the duration of conduction block with amide-type local anesthetics EXCEPT the
a. pH of tissues in the area of injection
b. Degree of vasodilatation caused by the local anesthetic
c. Blood plasma cholinesterase levels
d. Blood flow through the area of conduction block
e. Concentration of the injected anesthetic solution
C
Which of the following is contraindicated for a patient who had an
allergic reaction to procaine six months ago?
a. Nerve block with lidocaine
b. Topical application of lidocaine
c. Topical application of tetracaine
d. Infiltration with an antihistamine
C
Bupivacaine (Marcaine ) has all of the following properties relative to
lidocaine (Xylocaine ) EXCEPT bupivacaine
a. Is more toxic
b. Is an ester-type local anesthetic
c. Has a slower onset of action
d. Has a longer duration of action
D
Amide-type local anesthetics are metabolized in the
a. Serum
b. Liver
c. Spleen
d. Kidney
e. Axoplasm
B
The duration of action of lidocaine would be increased in the presence of which of the following medications? a. Prazosin b. Propranolol c. Hydrochlorothiazide d. Lisinopril e. Digoxin
B
Severe liver disease least affects the biotransformation of which of the following?
a. Lidocaine
b. Procaine
c. Prilocaine
d. Mepivacaine
B
A patient has been given a large volume of a certain local anesthetic solution and subsequently develops cyanosis with methemoglobinemia. Which of the following drugs most likely was administered?
a. Procaine
b. Prilocaine
c. Dibucaine
d. Lidocaine
e. Mepivacaine
B
Use of prilocaine carries the risk of which of the following adverse effects? a. Porphyria b. Renal toxicity c. Gastric bleeding d. Methemoglobinemia
D
The most probable cause for a serious toxic reaction to a local
anesthetic is
a. Psychogenic
b. Deterioration of the anesthetic agent
c. Hypersensitivity to the vasoconstrictor
d. Hypersensitivity to the local anesthetic
e. Excessive blood level of the local anesthetic
E
High plasma levels of local anesthetics may cause
a. Inhibition of peristalsis
b. stimulation of baroreceptors resulting in severe hypotension
c. Inhibition of the vagus nerve to the heart
d. Depression of inhibitory neurons in the CNS
D
Unfortunately, you injected your lidocaine intra-arterially. The first sign of lidocaine toxicity that might be seen in the patient would be
a. Elevated pulse rate
b. Sweating
c. CNS excitation
d. Cardiovascular collapse
e. CNS depression
C
The first sign that your patient may be experiencing toxicity from too much epinephrine would be
a. Cardiovascular collapse
b. Convulsions
c. Elevated pulse rate
d. Slurred speech
C
Which disease condition would make the patient most sensitive to the epinephrine in the local anesthetic?
a. Grave’s disease
b. Diabetes
c. HIV
d. Alcoholism
e. Schizophrenia
A
Cardiovascular collapse elicited by a high circulating dose of a local anesthetic may be caused by
a. Syncope
b. Vagal stimulation
c. Histamine release
d. Myocardial depression
e. Medullary stimulation
D
The most serious consequence of systemic local anesthetic toxicity is
a. Vertigo
b. Hypertension
c. Hyperventilation
d. Post depressive central nervous system convulsions
e. Postconvulsive central nervous system depression
E
Hypotensive shock may result from excessive blood levels of each of the following local anesthetics EXCEPT a. Cocaine b. Procaine c. Lidocaine d. Tetracaine e. Mepivacaine
A
Which of the following anesthetic drugs produces powerful stimulation of the cerebral cortex? a. Cocaine b. Procaine c. Lidocaine d. Tetracaine e. Mepivacaine
A
Local anesthetics block nerve conduction by
a. Depolarizing the nerve membrane to neutrality
b. Increasing membrane permeability to K+
c. Increasing membrane permeability to Na+
d. Preventing an increase in membrane permeability to K+
e. Preventing an increase in membrane permeability to Na+
E
Which of the following is true regarding the mechanism of action of local anesthetics?
a. Usually maintain the nerve membrane in a state of
hyperpolarization
b. Prevent the generation of a nerve action potential
c. Maintain the nerve membrane in a state of depolarization
d. Prevent increased permeability of the nerve membrane to potassium ions
e. Interfere with intracellular nerve metabolism
B
Local anesthetic agents prevent the generation of nerve impulses by
a. Decreasing threshold for stimulation
b. Decreasing resting membrane potential
c. Decreasing inward movement of sodium ion
d. Increasing inward movement of potassium ion
C
Local anesthetics interfere with the transport of which of the following ions during drug-receptor interaction a. Sodium b. Calcium c. Chloride d. Potassium e. Magnesium
A
If the pH of an area is lower than normal body pH, the membrane
theory of local anesthetic action predicts that the local anesthetic activity would be
a. Greater, owing to an increase in the free-base form of the drug
b. Greater, owing to an increase in the cationic form of the drug
c. Less, owing to an increase in the free-base form of the drug
d. Less, owing to a decrease in the free-base form of the drug
e. None of the above
D
A local anesthetic injected into an inflamed area will NOT give
maximum effects because
a. The pH of inflamed tissue inhibits the release of the free base
b. The drug will not be absorbed as rapidly because of the decreased blood supply
c. The chemical mediators of inflammation will present a chemical antagonism to the anesthetic
d. Prostaglandins stabilize the nerve membrane and diminish the effectiveness of the local anesthetic
A
The penetration of a local anesthetic into nervous tissue is a function
of the
a. Length of the central alkyl chain
b. Lipid solubility of the ionized form
c. Lipid solubility of the unionized form
d. Ester linkage between the aromatic nucleus and the alkyl chain
e. Amide linkage between the aromatic nucleus and the alkyl chain
C
At a pH of 7.8, lidocaine (pKa = 7.8) will exist in
a. the ionized form
b. the nonionized form
c. an equal mixture of ionized and nonionized forms
d. a mixture 10 times more ionized than nonionized forms
C
The more rapid onset of action of local anesthetics in small nerves is
due to
a. The slightly lower pH of small nerves
b. The greater surface-volume ratio of small nerves
c. The increased rate of penetration resulting from depolarization
d. Smaller nerves usually having a higher threshold
B
Which of the following statements are true regarding onset, degree and duration of action of local anesthetics?
a. The greater the drug concentration, the faster the onset and the greater the degree of effect
b. Local anesthetics block only myelinated nerve fibers at the nodes of Ranvier
c. The larger the diameter of the nerve fiber, the faster the onset of effect
d. The faster the penetrance of the drug, the faster the onset of
effect
i. (a), (b), and (c)
ii. (a), (b) and (d)
iii. (a) and (c) only
iv. (b), (c) and (d)
ii
A dentist administers 1.8 ml of a 2% solution of lidocaine. How many mg of lidocaine did the patient receive?
a. 3.6
b. 9
c. 18
d. 36
e. 180
D
2% solution = 20 mg/ml X 1.8 ml = 36 mg lidocaine.
Three ml of a local anesthetic solution consisting of 2% lidocaine with 1:100,000 epinephrine contains how many milligrams of each?
a. 6 mg. lidocaine, 0.3 mg. epinephrine
b. 6 mg. lidocaine, 0.03 mg. epinephrine
c. 60 mg. lidocaine 0.3 mg. epinephrine
d. 60 mg. lidocaine 0.03 mg epinephrine
e. 600 mg lidocaine, 0.3 mg. epinephrine
f. 600 mg. lidocaine, 0.03 mg. epinephrine
D
2% lidocaine = 20 mg/ml x 3 = 60 mg lidocaine 1:100,000 epi = 0.01 mg/ml x 3 = 0.03 mg epi
The maximum allowable adult dose of mepivacaine is 300 mg. How many milliliters of 2% mepivacaine should be injected to attain the maximal dosage in an adult patient?
a. 5
b. 10
c. 15
d. 20
e. 25
C
2% mepivacaine = 20 mg/ml, so 300 mg / 20 mg/ml = 15 ml
A recently introduced local anesthetic agent is claimed by the manufacturer to be several times as potent as procaine. The product is available in 0.05% buffered aqueous solution in 1.8 ml. cartridge. The maximum amount recommended for dental anesthesia over a 4- hour period is 30 mg. The amount is contained in approximately how many cartridges?
a. 1-9
b. 10-18
c. 19-27
d. 28-36
e. Greater than 36
D
0.05% = 0.5 mg/ml . To give 30 mg, you have to give 30mg/0.5 mg/ml or 60 ml. 1 cartridge = 1.8 ml, thus 60ml /1.8ml = 33.3 cartridges. - first express the percentage of solution as a fraction of 100, then add the units gm/ml. 0.05% equals 0.5 or 1/2 gms per 100 ml. The cartridge is 1.8 ml which you can round off to almost 2 mls total. In this 2 ml you would have 1 gm of the local anesthetic. You need to give 30 gms, which would require 30 cartridges.
According to AHA guidelines, the maximum # of carpules of local anesthetic containing 1:200,000 epinephrine that can be used in the patient with cardiovascular disease is
a. 1
b. 2
c. 3
d. 4
e. 11
D
For treating most oral infections, penicillin V is preferred to penicillin G
because penicillin V
a. Is less allergenic
b. Is less sensitive to acid degradation
c. Has a greater gram-negative spectrum
d. Has a longer duration of action
e. Is bactericidal, whereas penicillin G is not
B
The sole therapeutic advantage of penicillin V over penicillin G is
a. Greater resistance to penicillinase
b. Broader antibacterial spectrum
c. More reliable oral absorption
d. Slower renal excretion
e. None of the above
C
Which of the following penicillins is administered ONLY by deep intramuscular injection? a. Ampicillin b. Dicloxacillin sodium c. Penicillin G procaine d. Penicillin V potassium
C
The principal difference among potassium, procaine and benzathine salts of penicillin G is their
a. Potency
b. Toxicity
c. Duration of action
d. Antibacterial spectrum
e. Diffusion into the cerebrospinal fluid
C
Which of the following antibiotics is cross-allergenic with penicillin and should NOT be administered to the penicillin-sensitive patient?
a. Ampicillin
b. Erythromycin
c. Clindamycin
d. Lincomycin
e. Tetracycline
A
Which of the following antibiotics may be cross-allergenic with penicillin?
a. Neomycin
b. Cephalexin
c. Clindamycin
d. Erythromycin
e. All of the above
B
Which of the following antibiotics shows an incidence of approximately 8% cross-allergenicity with penicillins?
a. neomycin
b. cephalexin
c. bacitracin
d. vancomycin
e. tetracycline
B
Which of the following groups of antibiotics is related both structurally and by mode of action to the penicillins?
a. Polymyxins
b. Cycloserines
c. Cephalosporins
d. Chloramphenicols
C
For the dentist, the most reliable method of detecting a patient’s allergy to penicillin is by
a. Injecting penicillin intradermally
b. Taking a thorough medical history
c. Placing a drop of penicillin on the eye
d. Having the patient inhale a penicillin aerosol
e. Injecting a small amount of penicillin intravenously
B
Which of the following antibiotics is the substitute of choice for penicillin in the penicillin-sensitive patient?
a. Bacitracin
b. Erythromycin
c. Tetracycline
d. Chloramphenicol
B
Most anaphylactic reactions to penicillin occur
a. When the drug is administered orally
b. In patients who have already experienced an allergic reaction to the drug
c. In patients with a negative skin test to penicillin allergy
d. When the drug is administered parenterally
e. Within minutes after drug administration
i. (a), (b) and (d)
ii. (b), (c) and (d)
iii. (b), (d) and (e)
iv. (b) and (e) only
v. (c), (d) and (e)
iii
Which of the following penicillins has a broader gram-negative spectrum than penicillin G?
a. Nafcillin
b. Ampicillin
c. Cephalexin
d. Methicillin
e. Penicillin V
B
Which of the following penicillins has the best gram-negative spectrum?
a. Nafcillin
b. Ampicillin
c. Methicillin
d. Penicillin V
e. Phenethicillin
B
Which of the following antibiotics should be considered the drug of
choice in the treatment of infection caused by a penicillinase- producing staphylococcus?
a. Neomycin
b. Ampicillin
c. Tetracycline
d. Penicillin V
e. Dicloxacillin
E
Oral infections caused by organisms that produce penicillinase should be treated with
a. Ampicillin
b. Dicloxacillin
c. Erythromycin
d. Any of the above
e. Only (a) or (c) above
B
Which of the following antibiotics is LEAST effective against penicillinase-producing microorganisms?
a. Ampicillin
b. Cephalexin
c. Methicillin
d. Clindamycin
e. Erythromycin
A
Which of the following is a bactericidal antibiotic used specifically in the treatment of infections caused by Pseudomonas species and indole-positive Proteus species?
a. Ampicillin
b. Penicillin V
c. Tetracycline
d. Dicloxacillin
e. Carbenicillin
E
Penicillin’s effectiveness against rapidly growing cells is primarily due to its effect on
a. Protein synthesis
b. Cell wall synthesis
c. Nucleic acid synthesis
d. Chelation of metal ions
e. Cell membrane permeability
B
Chlortetracycline acts by interfering with
a. Cell wall synthesis
b. Nuclear acid synthesis
c. Protein synthesis on bacterial but not mammalian ribosomes
d. Protein synthesis on mammalian but not bacterial ribosomes
C
The probable mechanism of the bacteriostatic action of sulfonamides involves
a. Disruption of the cell membrane
b. Coagulation of intracellular proteins
c. Reduction in oxygen utilization by the cells
d. Inhibition of metabolism by binding acetyl groups
e. Competition with para-aminobenzoic acid in folic acid synthesis
E
The sulfonamides act by
a. Suppressing bacterial protein synthesis
b. Inhibiting the formation of the cytoplasmic bacterial membrane
c. Inducing the formation of “lethal” bacterial proteins
d. Inducing a deficiency of folic acid by competition with para-
aminobenzoic acid
D
Which antibiotic is able to achieve a higher concentration in bone than in serum?
a. penicillin
b. erythromycin
c. clindamycin
d. metronidazole
e. amoxicillin
C
Tetracycline reduces the effectiveness of concomitantly administered penicillin by
a. Reducing absorption of penicillin
b. Increasing metabolism of penicillin
c. Increasing renal excretion of penicillin
d. Increasing binding of penicillin to serum proteins
e. None of the above
E
tetracycline is bacteriostatic and would slow the rapid growth of the microbial population that a bactericidal drug such as penicillin needs to be effective, sine only when rapidly dividing are the cells making cell walls
The action of which of the following drugs will most likely be impaired by concurrent administration of tetracycline?
a. Clarithromycin
b. Erythromycin
c. Sulfonamide
d. Penicillin
e. Lincomycin
D
Which of the following antibiotics is most likely to cause liver damage?
a. Streptomycin
b. Penicillin G
c. Tetracycline
d. Cephalosporins
e. Amphotericin B
C
Which of the following erythromycins associated with an allergic cholestatic hepatitis?
a. Erythromycin base
b. Erythromycin stearate
c. Erythromycin estolate
d. Erythromycin succinate
C
Which of the following antibiotics is LEAST likely to cause superinfection?
a. Gentamicin
b. Tetracycline
c. Penicillin G
d. Streptomycin
e. Chloramphenicol
C
Gastrointestinal upset and pseudomembranous colitis has been prominently associated with
a. Nystatin
b. Cephalexin
c. Clindamycin
d. Polymyxin B
e. Erythromycin
C
Symptoms that may be characterized as allergic manifestations during penicillin therapy are
a. Deafness, dizziness and acute anemia
b. Crystalluria, nausea, vomiting and anaphylactic shock
c. Oliguria, hematuria, bronchoconstriction and cardiovascular collapse
d. Dermatitis, stomatitis, bronchoconstriction and cardiovascular collapse
D
Aplastic anemia is a serious toxic effect that occurs particularly after a course of treatment with which of the following antibiotics?
a. Penicillin
b. Lincomycin
c. Tetracycline
d. Streptomycin
e. Chloramphenicol
E
Each of the following is a side effect of prolonged tetracycline
hydrochloride therapy EXCEPT:
a. Suprainfection
b. Photosensitivity
c. Vestibular disturbances
d. Discoloration of newly forming teeth
e. Gastrointestinal symptoms (when administered orally)
C
Colitis that results following clindamycin therapy is caused by an overgrowth of
a. C. dificile
b. Staph aureus
c. Pseudomonas
d. Candida albicans
A
Which antibiotic is appropriate for premedication in the penicillin allergic patient?
a. Cephalexin
b. Clindamycin
c. Erythromycin
d. Amoxicillin
e. Ampiciilin
B
Acyclovir is useful for treating
a. Candidiasis
b. Colitis
c. Herpes simplex
d. HIV
e. ANUG
C
A distinct advantage that tetracyclines have over penicillins is that tetracyclines
a. Have no side effects
b. Do not cause superinfections
c. Are safer to use during pregnancy
d. Have a wider range of antibacterial activity
e. Produce higher blood levels faster after oral administration
D
Which of the following has the broadest antimicrobial spectrum?
a. Vancomycin (Vancocin )
b. Clindamycin (Cleocin )
c. Erythromycin (Erythrocin )
d. Chlortetracycline (Aureomycin )
e. A third generation cephalosporin
D
Sulfonamides and trimethoprim are synergistic bacteriostatic agents because in bacteria they
a. Both inhibit folic acid synthesis
b. Interfere sequentially with folic acid production
c. Are both antimetabolites of para-aminobenzoic
d. Are both inhibitors of dihydrofolic acid reductase
e. Are both transformed in vivo into a single active compound
B
Which of the following substances is the most effective agent against
fungus infections of the mucous membrane?
a. Nystatin ointment
b. Undecylenic acid
c. Polymyxin ointment
d. Saturated magnesium sulfate
e. 10 per cent aluminum chloride solution
A
The most desirable property of an antibiotic when used to treat an odontogenic infection is
a. Rapid absorption
b. Little allergenicity
c. Ability to achieve and maintain adequate concentrations at the
site of infection
d. Lack of significant binding to plasma proteins
e. No effects on drug metabolism
C
Nystatin is of greatest clinical usefulness in treating
a. viral infections
b. fungal infections
c. spirochetal infections
d. Bacterroides infections
e. penicillin resistant gram positive infections
B
- Which of the following drugs chelates with calcium?
a. Erythromycin
b. Polymyxin B
c. Tetracycline
d. Penicillin G
e. Chloramphenicol
C
Which of the following is NOT characteristic of tetracycline
antibiotics?
a. Absorption is impaired when taken with antacids
b. They predispose to monilial superinfection
c. They form a stable complex with the developing tooth matrix
d. They have a low tendency for sensitization, but a high
therapeutic index
e. They are effective substitutes for penicillin prophylaxis against
infective endocarditis
E
The concurrent administration of penicillin G and probenecid results in
a. Increased metabolism of penicillin G.
b. Increased renal excretion of probenecid
c. Decreased renal excretion of penicillin G
d. Decreased bactericidal effect of penicillin G
e. Increased excretion of probenecid in the feces
C
Interaction between penicillin and probenicid is best described by which of the following mechanisms?
a. competition at the receptor site
b. acceleration of drug biotransformation
c. alteration in the acid-base balance
d. alteration in the rate of renal clearance
D
When broad-spectrum antibiotics are administered with coumarin anticoagulants, the anticoagulant action may be
a. Reduced because of enhanced hepatic drug metabolism
b. Reduced because of increased protein-binding
c. Increased because of reduction of vitamin K sources
d. Increased because of decreased renal excretion of the anticoagulant
C
The therapeutic effectiveness of which of the following drugs will be most affected by concomitant ingestion of antacids?
a. Cephalexin
b. Erythromycin
c. Tetracycline
d. Sulfisoxazole
e. Penicillin V
C
Erythromycin should be avoided in the patient taking
a. Aspirin
b. Seldane
c. Benadryl
d. Ibuprofen
e. Propranolol
B
Quinidine is principally used to treat
a. Hypertension
b. Angina pectoris
c. Congestive heart failure
d. Supraventricular tachyarrhythmias
D
Quinidine is used to treat
a. Hypertension
b. Angina pectoris
c. Atrial fibrillation
d. Ventricular fibrillation
e. Congestive hear failure
C
Verapamil is most efficacious in the treatment of
a. Atrial fibrillation
b. Atrial tachycardia
c. Ventricular tachycardia
d. Catecholamine-induced arrhythmias
A
Which of the following drugs is most useful in treating or preventing angina pectoris?
a. Digitalis
b. Quinidine
c. Propranolol
d. Procainamide
e. Pentobarbital
C
Each of the following drugs can be used in the prevention and treatment of angina pectoris EXCEPT a. Digitalis b. Propranolol c. Nitroglycerin d. Isosorbide dinitrate e. Pentaerythritol tetranitrate
A
All of the following drugs are useful in the treatment of hypertension EXCEPT
a. Ephedrine
b. Reserpine
c. Methyldopa
d. Thiazide diuretics
A
Digitalis is useful in the treatment of which of the following conditions?
a. Atrial fibrillation
b. Congestive heart failure
c. Paroxysmal atrial tachycardia
d. All of the above
D
