Pharmacology feels overwhelming at first. There are hundreds of drugs, dozens of mechanisms, and endless side effects to learn. The good news: boards test the same core concepts again and again. Master these 10 areas and you will cover the vast majority of pharmacology questions.

Top 10 High-Yield Pharmacology Concepts

  1. Autonomic drugs (cholinergic and adrenergic) — Understand agonists and antagonists at muscarinic, nicotinic, alpha, and beta receptors, and what happens clinically when you stimulate or block each one.

  2. Beta-blockers — Used for hypertension, heart failure, angina, and arrhythmias; non-selective beta-blockers (propranolol) block both β1 and β2 receptors, while cardioselective agents (metoprolol, atenolol) prefer β1.

  3. ACE inhibitors and ARBs — ACE inhibitors (ending in -pril) block conversion of angiotensin I to II; ARBs (ending in -sartan) block the angiotensin II receptor directly; both are first-line for hypertension with diabetes or heart failure, but only ACE inhibitors cause a dry cough.

  4. Diuretics — Loop diuretics (furosemide) act on the thick ascending limb; thiazides act on the distal convoluted tubule; potassium-sparing agents (spironolactone, amiloride) act on the collecting duct; know which ones cause hypokalemia versus hyperkalemia.

  5. Antibiotics by mechanism — Group antibiotics by how they kill bacteria: cell-wall synthesis inhibitors (beta-lactams, vancomycin), protein synthesis inhibitors (aminoglycosides, macrolides, tetracyclines, chloramphenicol), DNA replication inhibitors (fluoroquinolones), and cell membrane disruptors (polymyxins).

  6. Anticoagulants — Heparin activates antithrombin III and works quickly (IV/SC); warfarin inhibits vitamin K-dependent clotting factors (II, VII, IX, X) and requires INR monitoring; direct oral anticoagulants (DOACs) such as rivaroxaban and apixaban inhibit factor Xa, while dabigatran inhibits thrombin directly.

  7. Common drug toxicities and their antidotes — Acetaminophen overdose → N-acetylcysteine; opioid overdose → naloxone; benzodiazepine overdose → flumazenil; heparin overdose → protamine sulfate; warfarin overdose → vitamin K (and fresh frozen plasma for urgent reversal).

  8. CYP450 inducers and inhibitors — These enzymes metabolize most drugs; inducers speed up metabolism (lowering drug levels), while inhibitors slow it down (raising drug levels and increasing toxicity risk).

  9. NSAIDs — Non-selective NSAIDs (ibuprofen, naproxen) inhibit both COX-1 and COX-2; COX-1 inhibition reduces gastric protection and platelet aggregation; COX-2 selective agents (celecoxib) spare the stomach but carry higher cardiovascular risk.

  10. Insulin and diabetes drugs — Rapid-acting insulins (lispro, aspart) peak in 1–2 hours; long-acting insulins (glargine, detemir) have no peak; metformin (first-line oral agent) works by reducing hepatic glucose output; sulfonylureas stimulate insulin secretion and can cause hypoglycemia.

Try 5 free questions right now to see how these topics appear on real exam-style questions.

Mnemonics to Remember Them

1. Drug suffix patterns — learn the drug class from the name

Many drug classes have consistent suffixes. Once you know the pattern, you can identify an unfamiliar drug's class immediately:

Suffix Drug Class Example
-olol Beta-blocker metopolol, atenolol
-pril ACE inhibitor lisipril, ramipril
-sartan ARB losartan, valsartan
-statin HMG-CoA reductase inhibitor atorvastatin, rosuvastatin
-tidine H2 blocker famotidine, ranitidine
-prazole Proton pump inhibitor omeprazole, lansoprazole
-floxacin Fluoroquinolone ciprofloxacin, levofloxacin
-cycline Tetracycline class doxycycline, minocycline
-mycin / -micin Aminoglycoside or macrolide gentamicin, erythromycin
-azole (antifungal) Azole antifungal fluconazole, itraconazole

This is just a taste — get our full library of pharmacology mnemonics free when you create an account.

2. CYP450 inducers — "PRISM"

Remembering what induces CYP enzymes (and therefore lowers drug levels) is a classic boards question:

Phenytoin, Rifampin, Isoniazid (weak), St John's Wort, Carbamazepine, Alcohol (chronic), Barbiturates

A popular mnemonic: "Queen Barbara Plays Rhymes in Carbamazepine's Shadow"

  • Quercetin/St John's Wort
  • Barbiturates
  • Phenytoin
  • Rifampin (the strongest inducer)
  • Carbamazepine
  • Alcohol (chronic use)

These drugs increase CYP450 activity → they lower levels of other drugs metabolized by the same enzyme. Classic example: rifampin reduces warfarin levels, increasing clot risk.

3. CYP450 inhibitors — "SICKFACES.COM"

Inhibitors slow metabolism → raise drug levels → increase toxicity risk. One well-known mnemonic for CYP3A4/mixed inhibitors:

Sodium valproate, Isoniazid, Cimetidine, Ketoconazole (and other azole antifungals), Fluoxetine/Fluvoxamine, Amiodarone, Chloramphenicol, Erythromycin (and other macrolides), Sulfonamides — .COM = Ciprofloxacin, Omeprazole, Metronidazole

Classic example: ketoconazole inhibits CYP3A4 → raises simvastatin levels → risk of myopathy.

Pharmacology questions on USMLE Step 1 often combine mechanism, side effect, and drug interaction in a single vignette. The best way to drill these patterns is with practice questions under timed conditions.

Play a quick pharmacology game to test your drug knowledge in a fast, mobile-friendly format — no signup needed.