NCLEX Pharmacology: 8 High-Yield Practice Questions
Pharmacology is consistently one of the most heavily tested categories on the NCLEX — appearing across all system-based questions, not just dedicated drug questions. These 8 questions mirror the NGN format: clinical judgment, priority, and safety.
A nurse is administering digoxin 0.25 mg PO to a patient with atrial fibrillation. Before administration, which assessment is MOST critical?
Explanation: Hold digoxin and notify provider if apical pulse is <60 bpm in adults. Digoxin toxicity can cause life-threatening bradycardia. The apical rate must be assessed for a full 60 seconds before each dose. Signs of toxicity: bradycardia, visual disturbances (yellow-green halos), nausea, and anorexia.
Q2Anticoagulants
A patient on warfarin therapy has an INR of 6.8 and is not bleeding. The most appropriate nursing action is:
Explanation: For supratherapeutic INR without active bleeding: hold warfarin and contact the provider for further orders. Vitamin K may be indicated (per provider order), but the nurse's first action is to hold the drug and notify. Protamine sulfate reverses heparin, not warfarin. IV vitamin K is for serious supratherapeutic INR or minor bleeding; major bleeding requires 4-factor PCC.
Q3Diuretics
A patient is prescribed furosemide 40 mg IV. Which assessment finding requires the nurse to contact the provider BEFORE administration?
Explanation: Furosemide (loop diuretic) causes potassium wasting (inhibits Na-K-2Cl cotransporter in loop of Henle). A pre-administration K+ of 3.2 mEq/L is already below normal (3.5–5.0 mEq/L); administering furosemide may cause dangerous hypokalemia, increasing risk of cardiac arrhythmias. Contact provider before giving.
Q4Pain Management / Opioid Safety
A nurse is caring for a patient on morphine PCA. The patient's respiratory rate is 8 breaths/min and they are difficult to arouse. The priority nursing action is:
Explanation: Respiratory rate <10 and sedation = opioid-induced respiratory depression — a medical emergency. Administer naloxone (opioid antagonist) immediately per standing orders or after stat provider notification. This is a life-threatening situation requiring immediate reversal, not reassessment or position change.
Q5Antidiabetics
A patient with type 1 diabetes receives regular insulin at 0700 with breakfast. The nurse should assess for hypoglycemia at what time?
Explanation: Regular insulin: onset 30–60 min, peak 2–3 hours, duration 5–8 hours. Hypoglycemia is most likely at the peak (2–3 hours post-injection) — around 0900–1000 if given at 0700. Rapid-acting insulin (lispro, aspart) peaks at ~1 hour. NPH peaks at 4–10 hours. Knowing onset/peak/duration is essential for NCLEX insulin questions.
Q6Psychiatric Medications
A patient on lithium therapy reports coarse hand tremor, polyuria, and nausea. Serum lithium level is 1.8 mEq/L. This finding represents:
Explanation: Therapeutic lithium range: 0.6–1.2 mEq/L (maintenance); 0.8–1.0 mEq/L is ideal for long-term. At 1.8 mEq/L, the patient is in early-moderate toxicity (range 1.5–2.0). Symptoms: coarse tremor, GI distress, confusion, polyuria. Above 2.0: severe toxicity (seizures, cardiac arrhythmias). Hold lithium and notify provider immediately.
Q7IV Medication Safety
A nurse administers IV vancomycin too rapidly. The patient develops flushing, erythema, and hypotension involving the face, neck, and upper torso. This is most likely:
Explanation: Red man syndrome is an infusion-related reaction from rapid vancomycin administration (histamine release, not IgE-mediated). Treat by stopping or slowing the infusion and administering diphenhydramine. Not a true allergy — vancomycin can be used again if infused slowly over ≥60–90 minutes. True vancomycin allergy is rare.
Q8Antihypertensive Medications
A patient taking an ACE inhibitor develops a dry, nonproductive cough 3 weeks after starting the medication. The nurse should:
Explanation: ACE inhibitor-induced cough (10–15% of patients, more common in women and Asian patients) is caused by accumulation of bradykinin. It will NOT resolve with continued use. Notify the provider — ARBs (e.g., losartan) block the angiotensin II receptor without affecting bradykinin and do not cause cough. Nurses should never discontinue prescription medications without a provider order.
How is pharmacology tested differently on NCLEX vs USMLE?
NCLEX pharmacology tests nursing judgment: priority actions, safe administration, monitoring parameters, and patient education — not drug mechanisms. USMLE tests mechanisms, drug interactions, and pharmacokinetics. For NCLEX, focus on: when to hold a drug, what to assess before giving it, signs of toxicity, and what to teach patients.
What are the most common NCLEX drug 'hold' criteria?
Hold and notify: digoxin if pulse <60 bpm; antihypertensives if SBP <90 (parameter varies); metformin before IV contrast; lithium if level >1.5 mEq/L; warfarin if INR supratherapeutic; beta-blockers if HR <60 or SBP <90; furosemide if K+ <3.5 mEq/L. Always check the specific parameter ordered — the NCLEX will often give you the lab value that triggers the hold.
Which drug interactions are highest priority on NCLEX?