USMLE Pharmacology Quiz

Master USMLE Pharmacology: Drug Mechanisms, Side Effects & Interactions

Pharmacology accounts for 15–22% of USMLE Step 1 and remains one of the highest-yield subjects for improving your score. Unlike anatomy or biochemistry, pharmacology questions appear across virtually every organ system block — a cardiology vignette may end with "which drug," a neurology question may ask about a side effect, and a renal case may test drug interactions. This free pharmacology quiz covers the three domains most frequently tested: mechanisms of action, side effects and toxicity, and drug interactions.

Drugs Covered in This Quiz

Mechanisms of Action section: Digoxin (Na+/K+ ATPase inhibition), Amiodarone (class III K+ channel blocker), Empagliflozin (SGLT2 inhibitor), Succinylcholine (depolarizing neuromuscular blocker metabolized by pseudocholinesterase), and Methotrexate (dihydrofolate reductase inhibitor used at low doses for rheumatoid arthritis and at high doses as an antineoplastic).

Side Effects & Toxicity section: Amiodarone pulmonary fibrosis (5–15% incidence, requires regular PFTs), Isoniazid-induced peripheral neuropathy (pyridoxine/B6 depletion), Valproic acid neural tube defects (spina bifida in 1–5% of exposed pregnancies), glucocorticoid-induced osteoporosis (most common cause of secondary osteoporosis), and statin rhabdomyolysis (CK >10x normal with myoglobinuria requiring aggressive IV hydration).

Drug Interactions section: Warfarin and metronidazole (CYP2C9/3A4 inhibition causing elevated INR), ACE inhibitors with potassium-sparing diuretics in CKD (life-threatening hyperkalemia), MAO inhibitors and dietary tyramine (hypertensive crisis from aged cheese, red wine, cured meats), NSAIDs and lithium (reduced renal prostaglandin synthesis decreasing lithium clearance), and rifampin with oral contraceptives (potent CYP3A4 induction increasing estrogen/progesterone metabolism).

Why Pharmacology Is High-Yield for USMLE Step 1

Pharmacology is unique among Step 1 subjects because it rewards pattern recognition over rote memorization. Most drug questions follow a predictable template: a clinical vignette establishes the diagnosis, then asks you to identify the drug (mechanism), predict the side effect, or recognize an interaction. Once you learn the ~200 highest-yield drug mechanisms and their associated toxicities, you can answer pharmacology questions across every system. Resources like Sketchy Pharmacology build visual associations, but active recall through practice questions — like the ones in this quiz — is what converts short-term memory into exam-day performance.

For additional practice, try our USMLE clinical vignette cases which integrate pharmacology into full patient scenarios, or use Lorea to generate custom MCQs from your pharmacology notes. You can also convert your Sketchy or First Aid PDFs into AI-generated summaries, study podcasts, or study songs for multi-modal review. Read our complete USMLE strategy guide for more tips.