NCLEX-RN: Pharmacology practice questions questions 1-25

Answer: B. Hold the dose and notify the provider

Topic: Digoxin toxicity

Nausea and yellow-green halos are classic signs of digoxin toxicity. Because digoxin has a narrow therapeutic index, the nurse must immediately hold the medication and notify the healthcare provider to prevent life-threatening cardiac arrhythmias.

Why the others are wrong

• A – Giving the dose with food delays necessary intervention and worsens life-threatening toxicity.
• C – These are signs of life-threatening toxicity, not expected or benign side effects.
• D – Administering an antiemetic masks toxicity symptoms while giving more digoxin worsens the poisoning.

Remember: Yellow halos and nausea mean digoxin toxicity: hold the dose immediately!

Written for the Medical Exam YouTube channel and answered blind by a second AI model before publication.

Answer: B. Decrease the heparin infusion rate.

Topic: Heparin and aPTT, protamine antidote

The aPTT is markedly above the therapeutic range, indicating excess anticoagulation. The safest step is to reduce the heparin infusion rate to bring the aPTT back into target, rather than stopping or reversing it.

Why the others are wrong

• A – Protamine is reserved for severe bleeding or very high aPTT, not mild excess.
• C – Continuing the current rate maintains supratherapeutic anticoagulation and bleeding risk.
• D – Increasing the rate would worsen the already high aPTT.

Remember: High aPTT → dial back heparin, not stop.

Written for the Medical Exam YouTube channel and answered blind by a second AI model before publication.

Answer: B. Insulin glargine

Topic: Insulin types and peak times

Insulin glargine is a long‑acting basal insulin that provides a relatively flat glucose‑lowering profile without a marked peak and maintains activity for approximately 24 hours, matching the described requirements.

Why the others are wrong

• A – Insulin lispro is rapid‑acting, peaks within an hour, not basal.
• C – NPH insulin has a pronounced peak and shorter duration than 24 hours.
• D – Insulin aspart is rapid‑acting, unsuitable for basal coverage.

Remember: Glargine = flat, 24‑hour basal insulin.

Written for the Medical Exam YouTube channel and answered blind by a second AI model before publication.

Answer: B. Hold the medication and prepare for a serum lithium draw.

Topic: Lithium toxicity signs

Persistent coarse tremor and diarrhea are early signs of lithium toxicity; the priority is to stop further exposure and obtain a serum lithium level to determine if the dose is supratherapeutic before any other interventions.

Why the others are wrong

• A – Antiparkinsonian agents treat tremor but do not address potential lithium toxicity.
• C – Continuing the dose and increasing fluids may worsen toxicity by raising lithium levels.
• D – Sodium restriction can increase lithium reabsorption, raising serum levels and toxicity risk.

Remember: Tremor + diarrhea → stop lithium, check level.

Written for the Medical Exam YouTube channel and answered blind by a second AI model before publication.

Answer: D. The cough is caused by an accumulation of bradykinin.

Topic: ACE inhibitor angioedema and cough

Ramipril is an ACE inhibitor; it blocks conversion of angiotensin I to II and also prevents breakdown of bradykinin, leading to its accumulation and a dry, persistent cough.

Why the others are wrong

• A – OTC cough suppressants treat symptoms but do not address the drug’s cause.
• B – The cough may persist; it is not guaranteed to resolve within a week.
• C – A severe allergic reaction would include rash, swelling, or difficulty breathing, not just cough.

Remember: ACE inhibitors trap bradykinin → dry cough.

Written for the Medical Exam YouTube channel and answered blind by a second AI model before publication.

Answer: D. Slow the infusion rate.

Topic: Vancomycin trough and red man syndrome

Facial flushing and itching are classic infusion‑related (anaphylactoid) reactions to vancomycin; the immediate nursing intervention is to slow the infusion (or stop temporarily) to reduce the reaction, as recommended by the label.

Why the others are wrong

• A – Trough level is therapeutic; reaction is infusion‑related, not due to concentration.
• B – Epinephrine is reserved for true anaphylaxis, not mild flushing/itching.
• C – Permanent discontinuation isn’t needed; adjusting the rate usually resolves the reaction.

Remember: Flushing? Slow the vancomycin drip, not stop it.

Written for the Medical Exam YouTube channel and answered blind by a second AI model before publication.

Answer: B. Monitor the client's respiratory rate and depth.

Topic: Opioid overdose and naloxone

After naloxone reverses opioid toxicity, the nurse must closely watch the client’s breathing because the drug’s effect may wear off before the opioid, risking recurrent respiratory depression.

Why the others are wrong

• A – Analgesia can wait; airway and breathing take precedence.
• C – Giving opioid may re‑induce overdose and worsen pain.
• D – Second naloxone dose is only needed if respiratory depression returns.

Remember: After naloxone, monitor breathing before treating pain.

Written for the Medical Exam YouTube channel and answered blind by a second AI model before publication.

Answer: B. Take the medication with water 1 hour before breakfast.

Topic: Levothyroxine administration

Levothyroxine is best absorbed on an empty stomach; taking it with water 30‑60 minutes before breakfast avoids food and mineral interactions that reduce bioavailability, ensuring consistent thyroid hormone levels.

Why the others are wrong

• A – Doubling a missed dose can cause overdose and cardiac toxicity.
• C – Bedtime dosing with food impairs absorption and may cause erratic thyroid levels.
• D – Calcium binds levothyroxine, markedly decreasing its absorption.

Remember: Take levothyroxine on empty stomach, 1 hour before breakfast.

Written for the Medical Exam YouTube channel and answered blind by a second AI model before publication.

Answer: A. High-pitched tinnitus

Topic: Aminoglycoside ototoxicity and nephrotoxicity

High-pitched tinnitus is the earliest clinical sign of aminoglycoside-induced cochlear damage. It indicates injury to the sensory hair cells before permanent high-frequency hearing loss develops, requiring immediate reporting to prevent irreversible damage.

Why the others are wrong

• B – Nephrotoxicity causes decreased urinary output and oliguria, not increased urinary output.
• C – Nystagmus indicates vestibular toxicity, which typically manifests after early cochlear signs like tinnitus.
• D – Aminoglycosides selectively damage high-frequency hearing first; low-frequency hearing loss occurs much later.

Remember: Aminoglycosides: A high-pitched ring is the earliest warning sign.

Written for the Medical Exam YouTube channel and answered blind by a second AI model before publication.

Answer: B. Hold the medication and notify the healthcare provider.

Topic: Beta blocker hold parameters

The client’s heart rate is 52 bpm and blood pressure is borderline low; metoprolol, a beta‑blocker, can further depress cardiac output, so the dose must be held and the prescriber notified before administration.

Why the others are wrong

• A – Blood pressure is not sufficiently high to justify giving a beta‑blocker now.
• C – An ECG is not the immediate priority before evaluating the medication dose.
• D – Reducing the dose does not address the risk of excessive bradycardia and hypotension.

Remember: Bradycardia + low BP = hold beta‑blocker, call provider.

Written for the Medical Exam YouTube channel and answered blind by a second AI model before publication.

Answer: C. Antiprotozoals

Topic: Giardiasis Treatment

Antiprotozoal agents target protozoan parasites such as Giardia lamblia; drugs like metronidazole, tinidazole, and nitazoxanide are classified as antiprotozoals and are first‑line therapy for giardiasis.

Why the others are wrong

• A – Treats fungal infections; Giardia is a protozoan, not a fungus.
• B – Targets helminths (worms); Giardia is a protozoan, not a worm.
• D – Acts against viruses; Giardia is a protozoan parasite, not a virus.

Remember: Giardia → antiprotozoal meds like metronidazole.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: B. SA node

Topic: Cardiac Conduction System

The sinoatrial node serves as the heart's primary intrinsic pacemaker, firing at an intrinsic rate of 60 to 100 beats per minute. Impulses originating here depolarize the atria and govern normal sinus rhythm.

Why the others are wrong

• A – Conducts impulses from the atrioventricular node down into the ventricular bundle branches.
• C – Acts as a secondary backup pacemaker firing at 40 to 60 beats per minute.
• D – Serves as the final conduction pathway, providing a slow backup pacemaker rate.

Remember: SA node sets the sinus pace: SA equals Starting Action.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: C. Increased heart rate

Topic: Sympathetic Nervous System Effects

Sympathetic stimulation activates β1‑adrenergic receptors in the heart, increasing pacemaker activity and contractility, which raises the heart rate. This is a hallmark of the fight‑or‑flight response.

Why the others are wrong

• A – SNS causes bronchodilation, not bronchoconstriction.
• B – SNS activation raises, not lowers, heart rate.
• D – SNS induces vasoconstriction, leading to hypertension, not hypotension.

Remember: SNS = fight‑or‑flight: heart races, lungs open, vessels tighten.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: C. Beta 2 receptor agonists

Topic: Bronchodilator Pharmacology

Beta‑2 receptor agonists stimulate airway smooth‑muscle β2 receptors, producing rapid bronchodilation; inhaled forms are the primary rescue and maintenance treatment for asthma and COPD in patients.

Why the others are wrong

• A – Alpha‑1 agonists cause vasoconstriction, not bronchodilation.
• B – Beta‑1 agonists act on cardiac tissue, not airway smooth muscle.
• D – Alpha‑2 agonists reduce sympathetic outflow, no direct airway effect.

Remember: Beta‑2 opens lungs, not heart.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: D. Tetracyclines

Topic: Tetracyclines and Dental Effects

Tetracyclines bind calcium in developing teeth and bone, leading to permanent yellow‑brown discoloration and enamel hypoplasia; therefore they are contraindicated in children under 8 years and in pregnancy.

Why the others are wrong

• A – Cause ototoxicity and nephrotoxicity, not dental staining.
• B – Safe for teeth; no calcium binding or discoloration.
• C – Do not affect tooth development; used safely in pregnancy.

Remember: Tetracycline stains teeth, avoid in kids and pregnancy.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: C. Increased gastric motility

Topic: Autonomic Nervous System

The sympathetic nervous system prepares the body for rapid action by increasing heart rate, sweating, and pupil dilation, while it inhibits gastrointestinal activity; therefore gastric motility decreases, making increased motility inconsistent with the fight‑or‑flight response.

Why the others are wrong

• A – Sweating enhances cooling for heightened metabolic activity.
• B – Pupil dilation improves visual acuity for rapid threat detection.
• D – Heart rate rises to supply muscles with oxygen during stress.

Remember: Sympathetic speeds up, not digests.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: D. Fluroquinolones

Topic: Fluoroquinolone Safety

Fluoroquinolones carry a black‑box warning because they can cause CNS effects (seizures, psychosis), worsen myasthenia gravis, and predispose to tendinitis or tendon rupture, especially in older adults.

Why the others are wrong

• A – Risk of photosensitivity and teeth staining; no black‑box for these reactions.
• B – No black‑box warning for CNS, MG, or tendon issues.
• C – Associated with nephro‑ and ototoxicity, not tendinopathy or MG worsening.

Remember: Fluoroquinolones: watch tendons, nerves, and myasthenia.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: A. Gram Positive

Topic: Staphylococcus aureus Classification

MRSA is a strain of Staphylococcus aureus, which is a Gram‑positive cocci; it retains crystal violet stain and appears purple on Gram stain and is identified by its resistance to β‑lactam antibiotics.

Why the others are wrong

• B – Mixed flora refers to polymicrobial infections, not a single organism like MRSA.
• C – MRSA is not Gram‑negative; it does not have an outer membrane.

Remember: MRSA = Gram‑positive cocci, purple on Gram stain.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: B. Hypertension

Topic: Tricyclic Antidepressant Side Effects

TCAs commonly cause anticholinergic symptoms, sexual dysfunction, and cardiac conduction delays such as QT prolongation; they tend to lower blood pressure, so hypertension is not a typical adverse effect.

Why the others are wrong

• A – Sexual dysfunction, especially decreased libido, is a known TCA side effect.
• C – Anticholinergic effects are classic TCAs, causing dry mouth, blurred vision, constipation.
• D – Prolonged QT can occur due to TCA-induced cardiac conduction abnormalities.

Remember: TCAs: dry, low BP, QT, not high BP.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: B. Antivirals

Topic: Herpes Simplex Treatment

Herpes simplex virus infections are managed with agents that inhibit viral replication, such as acyclovir, valacyclovir, or famciclovir; these are classified as antivirals and are the standard of care for primary and recurrent episodes.

Why the others are wrong

• A – Antiprotozoal drugs treat protozoa, not herpes virus.
• C – Antifungal medications act on fungi, ineffective against viruses.
• D – Antibacterial agents target bacteria, not viruses.

Remember: Herpes needs antivirals, not antibiotics or fungi drugs.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: B. Oral route

Topic: First‑Pass Metabolism

The first‑pass effect occurs when a drug absorbed from the gastrointestinal tract enters the portal vein and is metabolized by the liver before reaching systemic circulation, markedly reducing oral bioavailability.

Why the others are wrong

• A – Parenteral drugs enter systemic circulation directly, bypassing hepatic first‑pass metabolism.
• C – Pulmonary absorption delivers drug to the heart, not the portal vein.
• D – Topical agents act locally and are not subjected to hepatic first‑pass.

Remember: First‑pass = liver’s portal road after swallowing.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: B. Hypokalemia

Topic: Insulin Therapy Electrolytes

Insulin stimulates Na⁺/K⁺‑ATPase activity, moving potassium from the extracellular to the intracellular space, which can precipitate a clinically significant drop in serum potassium levels.

Why the others are wrong

• A – Serum sodium typically rises only with water loss, not insulin administration.
• C – Insulin drives potassium into cells, so serum potassium does not increase.
• D – Insulin does not cause excess free water retention leading to low sodium.

Remember: Insulin = potassium shift into cells → hypokalemia.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: C. Decongestant

Topic: Sympathomimetic Decongestants

Pseudoephedrine is a sympathomimetic decongestant; it directly stimulates α‑adrenergic receptors and causes indirect release of norepinephrine from presynaptic vesicles, producing nasal vasoconstriction and reduced edema.

Why the others are wrong

• A – Antihistamines block H1 receptors, not adrenergic pathways.
• B – Corticosteroids reduce inflammation via gene transcription, not adrenergic activation.
• D – Beta‑2 agonists relax bronchial smooth muscle, they do not cause norepinephrine release.

Remember: Pseudoephedrine = decongestant that mimics sympathetic nerves.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: C. Liver

Topic: Drug Metabolism

The liver is the body’s main “processing plant” for drugs, containing abundant cytochrome P450 enzymes and conjugating systems that carry out Phase I oxidation and Phase II conjugation reactions.

Why the others are wrong

• A – Spleen has minimal metabolic activity; primarily filters blood and immune cells.
• B – Kidney mainly excretes drugs; only minor metabolic role.
• D – Heart pumps blood; it does not metabolize drugs.

Remember: Liver = drug‑metabolism factory.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.

Answer: B. Parietal cells

Topic: Gastric Acid Secretion

Parietal cells are specialized epithelial cells located in the gastric glands of the stomach. They secrete hydrochloric acid to maintain an acidic gastric pH and produce intrinsic factor, which is essential for vitamin B12 absorption.

Why the others are wrong

• A – These cells secrete regulatory hormones like gastrin and somatostatin into the bloodstream, not acid.
• C – These cells secrete pepsinogen, an inactive enzyme precursor that is activated by hydrochloric acid.
• D – These cells secrete alkaline mucus and bicarbonate to protect the stomach lining from self-digestion.

Remember: Parietal cells produce pH-lowering acid; Chief cells secrete pepsinogen.

Question adapted from Nursing Pharmacology, by Open Resources for Nursing (Open RN); K. Ernstmeyer and E. Christman, editors (WisTech Open), licensed CC BY 4.0; wording and option order may differ from the book. The explanation is ours, checked against the book's answer.