Aspirin:

Correct Answer: B

Rationale: Aspirin, or acetylsalicylic acid, is metabolized to salicylic acid and acetic acid, not acetone, making the hydrolysis statement false. At low doses, it follows first-order kinetics, where elimination rate is proportional to concentration, a true statement reflecting its predictable clearance under therapeutic levels. It's primarily conjugated in the liver (e.g., to salicyluric acid), but excreted mainly via urine, not bile, so that's false. Aspirin irreversibly inhibits cyclooxygenase (COX) by acetylating it, unlike reversible NSAIDs, making that option false. The correct answer highlights aspirin's pharmacokinetic behavior at low doses, critical for its use in analgesia or cardioprotection, where steady-state effects depend on consistent elimination, contrasting with zero-order kinetics at overdose levels.

Correct Answer: B

Rationale: Fexofenadine for allergies may cause headache , a frequent side effect of this non-sedating antihistamine. Flank pain , otitis , infection , and tinnitus (E) are rare. Headache monitoring ensures safe symptom relief.

Correct Answer: B

Rationale: Protamine is the antidote for Heparin. Heparin is an anticoagulant medication that works by increasing the activity of antithrombin III, leading to the inhibition of clotting factors. In cases of excessive bleeding or overdose with Heparin, protamine can be administered to neutralize its anticoagulant effects. Protamine works by binding to heparin to form a stable complex, thereby reversing the anticoagulant activity of Heparin. It is important for healthcare providers to be familiar with the antidotes for various medications to manage potential complications effectively.

Correct Answer: D

Rationale: Fluvoxamine inhibits CYP450 enzymes. It is not an MAOI, has weak anticholinergic effects, and does not require weekly blood counts.

Correct Answer: C

Rationale: Chronic renal failure impairs kidney excretion, critical for drugs cleared renally-like metformin-raising toxicity risk if doses aren't adjusted, a targeted concern. Liver compensation aids metabolism, not excretion, so effectiveness isn't assured. Toxicity from all drugs assumes universal renal clearance, too broad. Decreased effectiveness ignores accumulation risks. Assessing for renal-excreted drugs' toxicity aligns with kidney function's role, ensuring safety by checking specific drug profiles.