Pharmacology Flashcards
Which medication is a GP IIb/IIIa antagonist and therefore inhibits the final common pathway of platelet aggregation?
A) Abcixamab
B) Aspirin
C) Clopidogrel
D) Enoxaparin (low molecular weight heparin)
E) Ticagrelor
A) Abcixamab
Which antidepressant is also used in the management of smoking cessation?
A) Amitryptiline
B) Bupropion
C) Citalopram
D) Sertraline
E) St John’s wort
F) Venlafaxine
= B) Bupropion
Explanation: Buproprion is a weak norepinephrine-dopamine-reuptake-inhibitor (NDRI) that is also thought to block the stimulatory effects of nicotine.
Which of the following antihypertensives is contraindicated during pregnancy?
A) Hydralazine
B) Labetalol
C) Methyldopa
D) Nifedipine
E) Ramipril
= E) Ramipril
Explanation: Methyldopa and labetalol are currently first line agents in the treatment of hypertension during pregnancy, while nifedipine, hydralazine and prazosin are used second line. ACE-inhibitors have an association with fetal death and neonatal renal failure in third-trimester use.
Which antibiotic is potentially both ototoxic and nephrotoxic?
A) Azithromycin
B) Cefazolin
C) Doxycycline
D) Gentamicin
E) Trimethoprim
= D) Gentamicin
Explanation: Aminoglycosides have bactericidal activity in which they bind to the bacteria ribosomal 30S subunit. The main noted adverse effects of aminoglycosides are ototoxicity, nephrotoxicity, and neuromuscular blockade.
Patients taking which antipsychotic require regular white blood cell count monitoring?
A) Clozapine
B) Fluphenazine
C) Haloperidol
D) Olanzapine
E) Risperidone
= A) Clozapine
Explanation: Agranulocytosis is a rare side-effect of clozapine. Other side-effects include a lower seizure threshold, myocarditis, metabolic syndrome, and QT prolongation.
What is the mechanism of thiazide diuretics such as chlorothiazide?
A ) Block the actions of the aldosterone receptor at the distal segment of the distal tubule
B ) Inhibit sodium-chloride transporter in the distal tubule
C ) Inhibit the sodium-potassium-chloride co-transporter in the thick ascending limb of the Loop of Henle
D ) Inhibit the transport of bicarbonate out of the proximal convoluted tubule into the interstitium
E ) Oppose the action of ADH on the collecting tubule
= B) Inhibit sodium-chloride transporter in the distal tubule
What is the mechanism of action of tiotropium?
A ) Combined long-acting beta agonist and corticosteroid
B ) Long-acting beta-agonist
C ) Long-acting muscarinic antagonist
D ) Short-acting beta agonist
E ) Short-acting muscarinic antagonist
= C) Long-acting muscarinic antagonist
Explanation: Tiotropium is a second-generation is a long-acting muscarinic receptor antagonist that exerts its primary therapeutic effect on the M1, M2, and M3 muscarinic acetylcholine receptors in the lungs preventing acetylcholine binding.
Which antibiotic is a DNA gyrase inhibitor and has the potential side-effect of causing tendonitis and tendon rupture?
A ) Amoxicillin
B ) Ciprofloxacin
C ) Gentamicin
D ) Trimethoprim
E ) Vancomycin
= B) Ciprofloxacin
Explanation: Ciprofloxacin is a fluroquinolone that is most often used in the coverage of gram negative rods of the urinary and GI tract. Side effects include headache and dizziness, prolonged QT interval, GI upset, skin rash, tendonitis, and tendon rupture.
Which medication is used to treat both urinary retention and hypertension?
A ) Clonidine
B ) Metoprolol
C ) Nitroglycerin
D ) Prazosin
E ) Propranolol
= D) Prazosin
Explanation: Prazosin is an alpha-1 antagonist that causes vasodilation by blocking the action of norepinephrine on vascular smooth muscle. It is used for the management of urinary retention, hypertension, phaeochromocytoma, and of nightmares associated with PTSD. As with other antihypertensives, it has the potential side-effects of orthostatic hypotension, headaches, and dizziness.
Which of the following medications is used in the management of both focal and generalised seizures?
A ) Donepazil
B ) Levetiracetam
C ) Levodopa
D ) Metoclopramide
E ) Prochlorperazine
Which of the following medications is used in the management of both focal and generalised seizures?
A ) Donepazil
B ) Levetiracetam
C ) Levodopa
D ) Metoclopramide
E ) Prochlorperazine
= B) Levetiracetam
Explanation: Levetiracetam (brand names: Keppra, Elepsia) is used to treat epilepsy. It is also used second-line in the management of status epilepticus.
Which of the following is an example of an SGLT2-inhibitor used in the management of type II diabetes mellitus?
A ) Acarbose
B ) Dapagliflozin
C ) Insulin glargine
D ) Metformin
E ) Repaglinide
= B) Dapagliflozin
Explanation: SGLT-2 inhibitors, such dapagliflozin and canagliflozin, block reabsorption of glucose in the proximal convoluted tubule.
Which diabetic drug has the rare but potential side-effect of lactic acidosis?
A ) GLP-1 agonists
B ) Meglitinides
C ) Metformin
D ) Sulfonylureas
E ) Thiazolidinediones
= C) Metformin
Explanation: Side effects of metformin include anorexia, epigastric discomfort, and diarrhoea. Lactic acidosis can potentially occur in patients with severe renal or hepatic disease.
A 28-year-old woman presented to the emergency department with breathing difficulty and increasing swelling of her face, eyes, lips, and tongue. An hour earlier she had received an intramuscular injection of ampicillin to treat acute pharyngitis. A diagnosis of anaphylactic reaction was made, and an intramuscular injection of epinephrine was given. Which of the following expected effects of the drug was most likely mediated by the activation of peripheral postsynaptic α2 receptors?
A ) Constriction of skin vessels
B ) Decreased secretion of insulin
C ) Dilation of skeletal muscle vessels
D ) Increased heart rate
E ) Increased secretion of renin
F ) Mydriasis
= B) Decreased secretion of insulin
= A) Adenosine
= Diltiazem
Amiodarone
- Amiodarone is one of the most commonly used anti-arrhythmic drugs. It is a primarily a class III antiarrhythmic. Like other antiarrhythmic drugs of this class, amiodarone works by blocking potassium rectifier currents that are responsible for the repolarization of the heart during phase 3 of the cardiac action potential. This potassium channel-blocking effect results in increased action potential duration and a prolonged effective refractory period in cardiac myocytes.
= Nitroglycerin
Similar to other nitrates used to treat anginal chest pain, nitroglycerin converts to nitric oxide (NO) in the body. This activity causes the relaxation of smooth muscle within blood vessels, resulting in the desired vasodilatory effect.
**= Ramipril **
Ramipril inhibits Angiotensin-Converting Enzyme and decreases Angiotensin II formation. As a result, sympathetic activity goes down, sodium and water reabsorption from the kidneys reduces, smooth muscles in the arterioles also relax.
Irbesartan
= Nifedipine
Nifedipine is a calcium channel blocker that belongs to the dihydropyridine subclass. It is primarily used as an antihypertensive and antianginal medication.
= Nimodipine
Nimodipine is a second-generation dihydropyridine calcium channel blocker. It was initially invented for the management of systemic hypertension. However, its use is restricted mainly to the management of vasospasm following subarachnoid hemorrhage.
= Hydralazine
= D) Hypokalaemia and hyperuricaemia
Common side effects include: hyponatremia, hypokalemia, hypomagnesemia, dehydration, hyperuricemia, gout, dizziness, postural hypotension, syncope.
Answer: Hypokalaemia, hyperuricaemia, hyponatremia, and hyperglycemia
= A) Hyperkalaemia and gynaecomastia
Spironolactone is a competitive aldosterone antagonist. Its mechanisms of action involve binding to the mineralocorticoid (e.g. aldosterone) receptor in the late portion of the distal tubule of the nephron and collecting ducts to prevent aldosterone binding and aldosterone-induced effects.
= F) Digoxin
- Digoxin toxicity is characterised by gastrointestinal distress, hyperkalemia and life-threatening dysryhthmias, including increased automaticity and AV nodal blockade
- Digoxin has a narrow therapeutic index and chronic toxicity is more likely in the elderly and those with renal impairment
A 46-year-old man complained to his physician of insomnia, nightmares, fatigue, diminished libido, and blanching of the fingers when exposed to cold. The man, who was recently diagnosed with exertional angina, had been taking a new drug for the past month. Which of the following medications most likely caused the patient’s symptoms?
A ) Isosorbide mononitrate
B ) Nifedipine
C ) Nitroglycerin
D ) Propranolol
E ) Verapamil
= D) Propranolol
= Amiodarone
= Adenosine
Adenosine acts via A1 adenosine receptors in the SA and AV node, which when stimulated open K+ channels causing hyperpolarisation and a reduction in Ca2+ current, with subsequent blockade of AV nodal conduction.
= E) Enalapril
In this case, as the patient has only a cough and is not breathless, the cause is very likely to be the ACE inhibitor (enalapril). This should be stopped and an angiotensin receptor antagonist (e.g. vasartan) started. Unlike ACE inhibitors, angiotensin receptor antagonists do not affect bradykinin metabolism and so do not produce a cough.
= Aspirin
= Bisphosphonates
= Metoprolol
Metoprolol is beta-1 selective and therefore avoids the bronchoconstriction that can occur as a side-effect of non-selective beta-blockers. Other beta-1-selective beta-blockers include atenolol, bisoprolol, and acebutalol.
**
= Alendronic acid
The most common reaction to bisphosphonates is irritation, inflammation, or ulceration of the oesophagus. As a precaution, therefore, it should be taken 30min before food (usually breakfast) and the patient should not lie down for at least 30min after taking the medication.
= ACE inhibitor
About 1-10% of patients will develop a dry, nonproductive paroxysmal cough on ACE-inhibitors.
= Statins
Elevated hepatic transaminases can rarely occur with statins. This is usually a transient effect and resolves with continued therapy or after brief therapy interruption.
**= Clindamycin **
Clindamycin is a lincosamide that inhibits bacterial protein synthesis and can be bacteriocidal or bacteriostatic. It is active against gram-positive cocci and anaerobes, but has little impact on gram-negative aerobes. Its penetration of bone makes it ideal for bone and joint infections.
Answer: metformin; biguanide; enhances the effect of insulin and is cardio-protective.
Answer: Amitriptyline
= Adenosine
Adenosine acts on receptors in the cardiac AV node, significantly reducing conduction time. This effect occurs by activation of specific potassium channels, driving potassium outside of cells, and inhibition of calcium influx, disrupting the resting potential of the slow nodal cardiac myocyte.
Which anti-emetic works via central and peripheral antagonism of serotonin at 5-HT3 receptors?
A ) Cyclizine
B ) Dexamethasone
C ) Droperidol
D ) Metoclopramide
E ) Ondansetron
= E ) Ondansetron
Which anti-arrhythmic drug blocks K+ channels and thereby prolongs phase 3 repolarisation?
A ) Amiodarone
B ) Flecainide
C ) Lidocaine
D ) Propranolol
E ) Verapamil
= A ) Amiodarone
Answer: Spironolactone
The Implanon MXT Implant contains etonogestrel. What synthetic hormone does this resemble?
A ) A combination of progesterone and oestrogen
B ) Human chorionic gonadotrophin
C ) Luteinising hormone
D ) Oestrogen
E ) Progesterone
= E) Progesterone
= Calcium channel blockers
= I) Statins
Statins are generally very safe. Muscle toxicity, including myonecrosis that leads to rhabdomyolysis, occurs in approximately 0.1% of patients.
= Aminoglycosides
Which diabetic drug works by decreasing gastrointestinal absorption of carbohydrates?
A ) Alpha-glucosidase inhibitors
B ) Biguanides
C ) Sodium-glucose linked transporter 2 (SGLT2) inhibitors
D ) Sulfonylureas
E ) Thiazolidinediones
= A) Alpha-glucosidase inhibitors
