Pharmacology Flashcards

Metformin's primary mechanism for lowering blood glucose in type 2 diabetes involves which action?

Answer: Decreasing hepatic glucose production via AMPK activation

Metformin activates AMPK, which decreases hepatic gluconeogenesis and glycogenolysis, lowering fasting glucose without causing hypoglycemia.

Which drug class is first-line for treating Helicobacter pylori eradication in combination with antibiotics?

Answer: Proton pump inhibitors

PPIs raise gastric pH, enhancing the activity of clarithromycin and amoxicillin in H. pylori triple therapy regimens.

A patient taking a selective serotonin reuptake inhibitor (SSRI) is prescribed tramadol for pain. What serious interaction risk exists?

Answer: Serotonin syndrome

Tramadol inhibits serotonin reuptake, and combined with an SSRI this can precipitate life-threatening serotonin syndrome.

Which pharmacokinetic parameter describes the fraction of an administered dose that reaches systemic circulation unchanged?

Answer: Bioavailability (F)

Bioavailability (F) accounts for first-pass metabolism, absorption efficiency, and other factors that reduce systemic drug availability.

Heparin's anticoagulant activity is primarily due to which mechanism?

Answer: Potentiation of antithrombin III to inhibit thrombin and factor Xa

Heparin binds antithrombin III, causing a conformational change that dramatically accelerates its inhibition of thrombin and factor Xa.

Which aminoglycoside toxicity is most associated with irreversible damage?

Answer: Ototoxicity

Aminoglycosides cause destruction of cochlear and vestibular hair cells, which do not regenerate, leading to permanent hearing loss.

Which enzyme is inhibited by statins, reducing endogenous cholesterol synthesis?

Answer: HMG-CoA reductase

Statins competitively inhibit HMG-CoA reductase, the rate-limiting enzyme in the mevalonate pathway for cholesterol biosynthesis.