Pharmacology Flashcards
7 cards from real NBME practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Pharmacology flashcards as text
A type 2 diabetic patient with normal renal function is started on metformin. Which mechanism accounts for its glucose-lowering effect?
Answer: Decreases hepatic gluconeogenesis via AMPK activation
Metformin activates AMPK, which suppresses hepatic gluconeogenesis and improves insulin sensitivity in peripheral tissues without causing hypoglycemia.
A patient on loop diuretics for heart failure develops muscle cramps and weakness. Which electrolyte abnormality most likely explains these symptoms?
Answer: Hypokalemia
Loop diuretics inhibit the Na-K-2Cl transporter in the thick ascending limb, causing urinary potassium wasting and hypokalemia, which leads to muscle dysfunction.
Which adverse effect is most specific to thiazide diuretics compared to loop diuretics?
Answer: Hyperglycemia and hyperuricemia
Thiazides cause hyperglycemia (decreased insulin secretion and peripheral resistance) and hyperuricemia (decreased uric acid secretion), effects not seen with loop diuretics.
A patient with Hashimoto's thyroiditis is prescribed levothyroxine. Which pharmacokinetic characteristic is most important to counsel the patient about?
Answer: Avoid calcium supplements and antacids within 4 hours
Calcium, iron, and antacids significantly reduce levothyroxine absorption by binding it in the GI tract; a 4-hour separation window is required.
Prednisone is prescribed for an acute asthma exacerbation. Which mechanism is responsible for its anti-inflammatory effect?
Answer: Binds glucocorticoid receptor → inhibits NF-κB → decreases cytokine transcription
Glucocorticoids bind intracellular receptors that translocate to the nucleus and inhibit NF-κB, reducing transcription of pro-inflammatory cytokines and mediators.
Cyclosporine is used to prevent organ rejection. Which mechanism accounts for its immunosuppressive action?
Answer: Inhibits calcineurin, preventing IL-2 transcription in T cells
Cyclosporine binds cyclophilin to form a complex that inhibits calcineurin, preventing NFAT dephosphorylation and IL-2 gene transcription in T cells.
A patient with type 1 diabetes needs basal insulin coverage. Which insulin formulation provides the longest duration of action with no pronounced peak?
Answer: Insulin glargine
Insulin glargine (Lantus) has a flat pharmacokinetic profile lasting ~24 hours with no peak due to its slow, steady absorption from subcutaneous precipitates.