pharmacology

Q- A patient with atrial fibrillation is treated with dofetilide. Which electrophysiologic effect explains the antiarrhythmic action of this drug? A- Decreased phase 0 depolarization B- Increased refractory period by potassium channel blockade C- Inhibition of calcium influx in AV node D- Sodium channel blockade during depolarization   Q- A patient treated with acetazolamide develops … Read more

Q- A patient with Parkinson’s disease is treated with selegiline. What is the primary mechanism of this drug? A- Inhibition of catechol-O-methyltransferase B- Inhibition of monoamine oxidase B C- Stimulation of dopamine receptors D- Stimulation of muscarinic receptors   Q- A patient treated with verapamil develops constipation and bradycardia. What class of drug does verapamil … Read more

Q- A patient treated with a nonselective beta blocker develops hypoglycemia that is difficult to recognize. What explains the masking of hypoglycemia symptoms? A- Alpha receptor blockade B- Beta-1 receptor stimulation C- Beta-2 receptor blockade D- Muscarinic receptor blockade   Q- A patient with hyperlipidemia is treated with cholestyramine. What is the primary mechanism by … Read more

Q- A patient receiving trimethoprim-sulfamethoxazole develops megaloblastic anemia. Which mechanism explains this adverse effect? A- Folate metabolism inhibition B- Hemoglobin oxidation C- Inhibition of erythropoietin synthesis D- Vitamin B12 malabsorption   Q- A patient with hypertension is treated with clonidine. What is the primary mechanism by which this drug lowers blood pressure? A- Alpha-1 receptor … Read more

Q- A patient treated with vancomycin develops acute kidney injury. Which concurrent medication increases this risk most significantly? A- Amoxicillin B- Azithromycin C- Gentamicin D- Metronidazole   Q- A patient who is taking a high dose of niacin for hyperlipidemia develops hyperglycemia. What explains this effect? A- Decreased insulin secretion B- Decreased peripheral glucose uptake … Read more

Q- A patient with heart failure is started on sacubitril/valsartan. What is the primary pharmacologic action of sacubitril? A- Angiotensin II receptor blockade B- Inhibition of neprilysin C- Inhibition of renin release D- Stimulation of natriuretic peptide receptors   Q- A patient taking linezolid develops thrombocytopenia after prolonged therapy. What is the underlying mechanism? A- … Read more