NCLEX Pharmacology

NCLEX Pharmacology: The Complete High-Yield Review

By a Resident Physician  ·  Updated 2025  ·  10 min read

Pharmacology questions make up 12–18% of the NCLEX. They are among the most high-yield and most feared section. Here's how to master them systematically.

How to Approach NCLEX Pharmacology

NCLEX pharm questions rarely ask "what is the mechanism of this drug?" Instead, they ask what you would assess before giving the drug, what side effect to monitor for, what patient teaching is needed, and what adverse reaction requires immediate action. Your pharmacology knowledge must be clinically applied, not just factual.

The 10 Most Tested Drug Classes

1. Anticoagulants

Heparin, warfarin, and direct oral anticoagulants (DOACs) appear on almost every NCLEX. Know: warfarin is reversed with vitamin K, heparin with protamine sulfate. Therapeutic INR for most conditions is 2.0–3.0. Monitor PTT for heparin, PT/INR for warfarin. DOACs require no routine monitoring.

2. Insulin

Know all insulin types and their peak action times. Rapid-acting (lispro, aspart) peaks in 1–2 hours. Regular peaks in 2–4 hours. NPH peaks in 4–12 hours. Glargine has no peak. "Cloudy before clear" for mixing insulins — NPH before regular. Signs of hypoglycemia before hyperglycemia on the NCLEX.

3. Digoxin

Therapeutic range: 0.5–2.0 ng/mL. Toxicity signs: nausea, vomiting, visual disturbances (yellow-green halos), bradycardia, dysrhythmias. Always check apical pulse for 1 full minute before administration. Hold if pulse below 60. Hypokalemia potentiates toxicity — monitor potassium.

4. Lithium

Therapeutic range: 0.6–1.2 mEq/L. Toxicity is a medical emergency. Early toxicity: tremor, nausea, polyuria. Moderate: confusion, coarse tremor, hyperreflexia. Severe: seizures, coma, cardiac dysrhythmias. Sodium depletion raises lithium levels — ensure adequate sodium and fluid intake.

5. ACE Inhibitors

Ends in "-pril." Classic side effects: dry cough (most common), angioedema (most dangerous — stop immediately), hyperkalemia. Contraindicated in pregnancy. Monitor creatinine and potassium. Teach patients to avoid NSAIDs and potassium supplements.

Drug ClassMonitorHold/Notify if
Beta-blockersBP, HR, blood glucoseHR <60, SBP <90
Calcium channel blockersBP, HR, peripheral edemaHR <60, SBP <90
Loop diureticsPotassium, BUN, urine outputK+ <3.5, oliguria
AminoglycosidesBUN, creatinine, hearingRising creatinine, tinnitus
PhenytoinDrug level, CBCLevel >20 mcg/mL

Antidotes You Must Know Cold

NCLEX trick: When a pharmacology question asks what you do "first" after giving a medication that caused an adverse reaction — always think: assess the patient first, notify the provider second, document third. Intervene based on severity — anaphylaxis gets epinephrine before calling the provider.

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