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Pharmacology NCLEX practice questions
Pharmacological and Parenteral Therapies is 13 to 19% of the NCLEX-RN. These questions cover high-alert medications, toxicity and antidotes, safe administration and drug classes by suffix. NCSBN does not publish a drug list and uses mostly generic names, so knowing suffixes pays off.
Question 1 · Pharmacological and Parenteral Therapies
A client's serum lithium level is 1.8 mEq/L. The therapeutic range is 0.6-1.2 mEq/L. Which nursing action is the priority?
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Answer: C. A level of 1.8 mEq/L exceeds the toxic threshold of above 1.5 mEq/L, so the nurse should hold the dose and notify the provider immediately. Administering the next dose would worsen toxicity and is unsafe. Documenting this as normal is incorrect because the level is clearly toxic. Restricting fluids is inappropriate because adequate hydration actually helps the kidneys eliminate lithium; restriction would worsen toxicity.
Checked against: OpenStax Psychiatric-Mental Health Nursing, 4.2; OpenStax Pharmacology for Nurses, 13.3
Question 2 · Pharmacological and Parenteral Therapies
A client is prescribed a continuous heparin infusion. Which laboratory value should the nurse monitor to evaluate therapeutic effect?
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Answer: C. Heparin therapy is monitored using aPTT, with a therapeutic goal of 1.5-2.5 times the control value. INR is used to monitor warfarin therapy, not heparin. Serum potassium is unrelated to heparin monitoring. Digoxin level monitors digoxin therapy, not heparin's anticoagulant effect.
Checked against: OpenStax Pharmacology for Nurses, 40.4; OpenStax Pharmacology for Nurses, 20.2
Question 3 · Pharmacological and Parenteral Therapies
The nurse is administering flumazenil to reverse benzodiazepine sedation. Which risk should the nurse monitor for after administration?
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Answer: A. Flumazenil reverses benzodiazepine effects but carries a risk of precipitating seizures, especially in clients who are benzodiazepine-dependent or have a seizure history, so close monitoring is required. Hyperkalemia is not an expected effect of flumazenil administration. Hepatotoxicity is associated with acetaminophen overdose, not flumazenil. Iron overload is unrelated to benzodiazepine reversal.
Checked against: pubmed.ncbi.nlm.nih.gov; ncbi.nlm.nih.gov
Question 4 · Safety and Infection Control
Before administering the first dose of amoxicillin, what is the priority nursing action?
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Answer: B. Amoxicillin belongs to the penicillin class (-cillin), and the priority action before administration is to ask about any history of penicillin allergy to prevent a potentially life-threatening hypersensitivity reaction. A complete blood count is not routinely required before administering penicillins. Renal function assessment is more relevant to aminoglycosides (-mycin/-micin). Baseline hearing assessment is important for aminoglycosides due to ototoxicity risk, not penicillins.
Checked against: OpenStax Pharmacology for Nurses, 7.1; OpenStax Medical-Surgical Nursing, 24.1
Question 5 · Reduction of Risk Potential
A client receiving ondansetron for chemotherapy-induced nausea has a baseline ECG that shows a QTc interval of 470 ms. What is the nurse's priority action?
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Answer: A. Ondansetron (-setron) can cause QT prolongation, and a QTc of 470 ms is already prolonged, so the nurse should notify the provider before giving the medication to prevent worsening cardiac arrhythmia risk such as torsades de pointes. Administering the drug without addressing this finding could be dangerous. Simply documenting and waiting 24 hours delays necessary intervention. Checking potassium in a week is too delayed given the immediate risk.
Checked against: dailymed.nlm.nih.gov; pubmed.ncbi.nlm.nih.gov
Question 6 · Safety and Infection Control
Which storage practice is appropriate for concentrated electrolyte solutions such as hypertonic saline and IV potassium chloride?
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Answer: C. Concentrated electrolytes such as hypertonic saline, IV potassium chloride, and magnesium must be stored separately with restricted access to prevent accidental administration errors that could be fatal. Keeping them as unrestricted floor stock increases the risk of a dangerous medication error. Storing them with oral medications does not provide the necessary safeguards for these high-alert substances. Unrestricted access for convenience defeats the purpose of the safety controls needed for concentrated electrolytes.
Checked against: pmc.ncbi.nlm.nih.gov; pubmed.ncbi.nlm.nih.gov
Question 7 · Reduction of Risk Potential
A client receiving IV gentamicin reports ringing in the ears. Which action should the nurse take first?
Show answer and rationale
Answer: C. Tinnitus indicates ototoxicity, a major toxicity associated with aminoglycosides like gentamicin and tobramycin, and must be reported to the provider immediately to prevent permanent hearing loss. Continuing the infusion without reporting risks worsening irreversible damage. Acetaminophen does not address the underlying cause of the ototoxicity. Simply decreasing the rate and waiting several hours delays the urgent provider notification needed to potentially stop the drug.
Checked against: openstax.org; dailymed.nlm.nih.gov
Question 8 · Pharmacological and Parenteral Therapies
A client receiving IV vancomycin develops sudden flushing, redness of the face and neck, and hypotension during the infusion. Which nursing action is most appropriate?
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Answer: D. Red man syndrome is an infusion-rate-related reaction rather than a true allergy, so stopping the infusion and slowing the rate for future doses typically resolves the symptoms and allows continued therapy. Increasing the infusion rate would worsen the reaction. Epinephrine is reserved for true anaphylaxis, which this is not. Discontinuing vancomycin permanently without provider notification is inappropriate since a slower rate often allows safe continuation of therapy.
Checked against: ncbi.nlm.nih.gov
Question 9 · Pharmacological and Parenteral Therapies
A nurse assesses a client's apical pulse for one full minute before the scheduled digoxin dose and finds a rate of 52 beats/min. What should the nurse do next?
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Answer: A. Digoxin slows AV conduction and can cause bradycardia or toxicity, so the apical pulse must be checked for a full minute before each dose; in an adult, a rate below 60 beats/min means the dose should be held and the provider notified. Giving the full or half dose despite bradycardia risks worsening the heart rate and possible arrhythmia. Simply reassessing later without holding the dose delays needed intervention and still exposes the client to an unsafe medication effect. The correct action always prioritizes safety by withholding the drug until further evaluation.
Checked against: OpenStax Pharmacology for Nurses, 17.6
Question 10 · Pharmacological and Parenteral Therapies
A client taking warfarin has an INR of 5.0. Which medication should the nurse expect the provider to prescribe?
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Answer: B. An INR of 5.0 is above the therapeutic goal of 2-3 and indicates excessive anticoagulation with a high bleeding risk; vitamin K (phytonadione) reverses warfarin's effect. Protamine sulfate is specific to heparin, not warfarin. Increasing the warfarin dose would worsen the supratherapeutic INR and bleeding risk. Deferoxamine treats iron toxicity and has no role here.
Checked against: OpenStax Pharmacology for Nurses, 20.2
Question 11 · Pharmacological and Parenteral Therapies
A client taking lisinopril reports a persistent dry cough. The provider wants to switch to a medication in a different class that will not cause this side effect. Which suffix should the nurse expect on the new prescription?
Show answer and rationale
Answer: B. Lisinopril is an ACE inhibitor (-pril), and a bothersome dry cough is a known class effect. ARBs (-sartan) work similarly to ACE inhibitors by blocking the renin-angiotensin system but do not cause the cough, making them the appropriate substitute. Beta blockers (-olol) and calcium channel blockers (-dipine) are different antihypertensive classes that would not be the direct substitute for cough management, and staying on another -pril drug would not resolve the cough since it is a class effect.
Checked against: OpenStax Medical-Surgical Nursing, 12.3; OpenStax Clinical Nursing Skills, 11.1
Question 12 · Pharmacological and Parenteral Therapies
A nurse is administering metoprolol to a client. Which assessment finding would require the nurse to hold the medication and notify the provider?
Show answer and rationale
Answer: B. Beta blockers such as metoprolol (-olol) lower heart rate and blood pressure, and the medication should be held if the heart rate is below 60/min because further slowing could cause symptomatic bradycardia. A blood pressure of 118/76 mmHg, respiratory rate of 16/min, and temperature of 37.2°C are all within normal limits and do not require holding the dose. Beta blockers should never be stopped abruptly due to the risk of rebound hypertension or tachycardia. The nurse should notify the provider when the heart rate is below the safe parameter.
Checked against: openstax.org; ncbi.nlm.nih.gov
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Frequently asked questions
Does the NCLEX have a list of drugs to study?
No. NCSBN does not publish a list of medications on the exam, and items mostly use generic names. Learning drug classes by suffix (like -olol, -pril, -statin) helps you reason about drugs you have not memorized.
How much of the NCLEX is pharmacology?
Pharmacological and Parenteral Therapies is 13 to 19% of the NCLEX-RN under the 2026 test plan.
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About these questions
Every question on this page was approved by a licensed RN, and its answer was checked against open nursing references (mostly OpenStax nursing textbooks) before publishing. They are NCLEX-style practice, not real NCLEX items. NurseLingo is not affiliated with NCSBN. Spot a problem? Tell us.