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NCLEX Pharmacology Practice Questions — Free

Free NCLEX pharmacology drills: drug interactions, calculations, side effects, and nursing implications, each with a full clinical rationale.

PharmacologyMed-SurgFundamentalsPediatricsPsychMaternity
Question 1Multiple choicePharmacology

A client with type 1 diabetes is prescribed insulin lispro. The nurse knows this insulin has which characteristic?

  1. Onset in 30–60 minutes, peak in 2–4 hours
  2. Onset in 10–15 minutes, peak in 1–2 hours
  3. Onset in 1–2 hours, no pronounced peak
  4. Onset in 4–6 hours, duration 24 hours
Show answer & rationale

Correct: Onset in 10–15 minutes, peak in 1–2 hours

Why: Insulin lispro is a rapid-acting analog: onset 10–15 min, peak 1–2 hr, duration 3–5 hr — so it must be injected within 15 minutes of starting to eat. Give it too early without food and hypoglycemia hits before the meal's glucose arrives. Regular insulin (30–60 min onset, 2–4 hr peak) is the '30 minutes before meals' insulin; glargine/detemir have no pronounced peak; NPH has a 4–6 hr onset with a distinct peak. Memory aid: lispro is lightning-fast — 'lispro' sounds like 'lightning', in and out within 15 minutes of eating.

📚 Basis: Rapid-acting analogs (lispro, aspart, glulisine): onset 10–15 min, peak 1–2 h, duration 3–5 h; administer within 15 min of a meal. · ADA Standards of Care 2026

Question 2Multiple choicePharmacology

A client taking digoxin reports nausea, anorexia, and seeing yellow-green halos around lights. The nurse's priority action is to:

  1. Reassure the client these are expected effects
  2. Hold the dose and notify the provider; check serum digoxin level
  3. Encourage oral fluids and recheck in 4 hours
  4. Administer the next dose with food
Show answer & rationale

Correct: Hold the dose and notify the provider; check serum digoxin level

Why: Nausea, anorexia, and yellow-green halos (xanthopsia) are classic digoxin toxicity, often joined by bradycardia or dysrhythmias. The nurse holds the dose, notifies the provider, and checks serum digoxin and potassium — hypokalemia potentiates toxicity even at 'therapeutic' levels. Never reassure or re-dose a client showing toxicity. Memory aid: think 'halos' — GI upset, yellow-green vision halos, and a slow pulse spell digoxin toxicity.

📚 Basis: Digoxin therapeutic range ~0.8–2.0 ng/mL (many labs flag >2.0 as toxic); toxicity signs: GI upset, visual changes (xanthopsia), bradycardia, dysrhythmias; hypokalemia increases toxicity risk. · AHA/ACC/HFSA heart failure guidelines

Question 3Multiple choicePharmacology

The antidote for heparin overdose is:

  1. Vitamin K
  2. Protamine sulfate
  3. Naloxone
  4. Calcium gluconate
Show answer & rationale

Correct: Protamine sulfate

Why: Protamine sulfate binds heparin into an inactive complex (about 1 mg protamine per 100 units of heparin). Vitamin K reverses warfarin, naloxone reverses opioids, and calcium treats hyperkalemia and magnesium toxicity — none of them reverse heparin. Memory aid: protamine reverses heparin — 'PROtamine PROtects' from heparin.

📚 Basis: Protamine ~1 mg neutralizes ~100 units of heparin (drug labeling / CHEST antithrombotic guidance). · CHEST antithrombotic therapy guidelines

Question 4Multiple choicePharmacology

A client on warfarin has an INR of 5.8 with no active bleeding. The nurse anticipates which order?

  1. Hold warfarin and administer vitamin K
  2. Increase the warfarin dose
  3. Start a heparin infusion
  4. No action; this is a therapeutic INR
Show answer & rationale

Correct: Hold warfarin and administer vitamin K

Why: Therapeutic INR is 2.0–3.0 for most indications (2.5–3.5 for mechanical valves). At 5.8 with no bleeding, guidance is to hold warfarin, adding low-dose oral vitamin K (1–2.5 mg) when bleeding risk is high. Major bleeding would require 4-factor prothrombin complex concentrate, not vitamin K alone. Memory aid: INR 2–3 is the sweet spot — 'two to three keeps you clot-free' without tipping into bleeding.

📚 Basis: Therapeutic INR 2.0–3.0; INR 4.5–10 without bleeding: hold warfarin ± vitamin K. · CHEST antithrombotic therapy guidelines

Question 5Multiple choicePharmacology

A client's lithium level is 1.8 mEq/L. The nurse recognizes this as:

  1. Therapeutic; continue the current dose
  2. Toxic; hold the dose and notify the provider
  3. Subtherapeutic; the dose should be increased
  4. Expected during the first week of therapy
Show answer & rationale

Correct: Toxic; hold the dose and notify the provider

Why: Therapeutic lithium is 0.6–1.2 mEq/L; toxicity begins around 1.5. At 1.8 the nurse holds the dose, notifies the provider, and assesses hydration, renal function, and neuro signs (tremor, confusion, ataxia). Dehydration, NSAIDs, and diuretics all raise levels. Memory aid: salt and lithium compete — dehydration and diuretics let lithium win (toxicity).

📚 Basis: Lithium therapeutic 0.6–1.2 mEq/L; toxicity generally >1.5 mEq/L; risk rises with dehydration, NSAIDs, thiazides. · Standard psychopharmacology references

Question 6Multiple choicePharmacology

A client starting alendronate for osteoporosis should be instructed to:

  1. Take it at bedtime with a full glass of milk
  2. Take it first thing in the morning with a full glass of water and remain upright for 30–60 minutes
  3. Chew the tablet thoroughly before swallowing
  4. Take it with an antacid to prevent heartburn
Show answer & rationale

Correct: Take it first thing in the morning with a full glass of water and remain upright for 30–60 minutes

Why: Bisphosphonates irritate the esophagus and absorb poorly with food, calcium, or antacids — so take on an empty stomach with a full glass of plain water and stay upright 30–60 minutes to prevent esophageal ulceration. Never chew, and never take at bedtime. Memory aid: 'sit up and sip plain water' — upright 30–60 minutes, empty stomach, water only.

📚 Basis: Bisphosphonates: take on empty stomach with plain water, remain upright 30–60 min; food/calcium/antacids impair absorption (FDA labeling). · FDA bisphosphonate labeling

Question 7Select all that applyPharmacology

A client receiving insulin is showing signs of hypoglycemia. Which findings does the nurse expect? Select all that apply.

  1. Shakiness and tremors
  2. Diaphoresis
  3. Confusion and irritability
  4. Tachycardia
  5. Flushed, dry skin
  6. Hunger
Show answer & rationale

Correct: Shakiness and tremors; Diaphoresis; Confusion and irritability; Tachycardia; Hunger

Why: Hypoglycemia triggers sympathetic activation (tremor, sweating, tachycardia, hunger) plus neuroglycopenia (confusion, irritability). Flushed, dry skin with fruity breath points to hyperglycemia/DKA — the opposite problem. Memory aid: cold and clammy, need some candy (hypoglycemia); hot and dry, sugar high (hyperglycemia).

📚 Basis: Hypoglycemia: adrenergic signs (tremor, diaphoresis, tachycardia, hunger) + neuroglycopenic signs (confusion); glucose <70 mg/dL. · ADA Standards of Care (hypoglycemia)

Question 8Select all that applyPharmacology

Which factors increase a client's risk of digoxin toxicity? Select all that apply.

  1. Hypokalemia
  2. Impaired renal function
  3. Advanced age
  4. Concurrent amiodarone therapy
  5. Hyperkalemia
Show answer & rationale

Correct: Hypokalemia; Impaired renal function; Advanced age; Concurrent amiodarone therapy

Why: Digoxin is renally cleared with a narrow therapeutic index: hypokalemia (more digoxin binds the Na⁺/K⁺ pump), renal impairment, advanced age, and P-glycoprotein inhibitors like amiodarone and verapamil all raise risk. Hyperkalemia appears in acute overdose from pump blockade — but chronic toxicity risk comes from hypokalemia. Memory aid: KARE — low K+, Advanced age, Renal impairment, Enzyme (P-gp) blockers raise digoxin risk.

📚 Basis: Digoxin: narrow therapeutic index, renal clearance; hypokalemia, renal impairment, age, and P-gp inhibitors (amiodarone, verapamil) raise toxicity risk. · AHA/ACC/HFSA heart failure guidelines

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PharmacologyMed-SurgFundamentalsPediatricsPsychMaternity

NCLEX Drill offers practice questions for study purposes only — not medical advice, and not a substitute for professional judgment or official study materials. Question bank grows daily; last updated 2026-10-09.