49 Pharmacology Practice Questions & Answers
Every Pharmacology practice question from the NCLEX-RN Practice Test, with the correct answer and a short explanation.
Start practice test →1. A client is prescribed warfarin, an anticoagulant. Which laboratory value is MOST important for the nurse to monitor to evaluate its therapeutic effect?
- A.Serum creatinine
- B.Serum potassium
- C.aPTT (activated partial thromboplastin time)
- D.PT/INR (prothrombin time / international normalized ratio)✓ Answer
Warfarin's therapeutic effect is monitored with PT/INR; a target INR of about 2.0–3.0 is typical for most indications.
2. A client receiving intravenous heparin, a high-alert anticoagulant, develops bleeding. Which medication should the nurse anticipate administering as the antidote?
- A.Flumazenil
- B.Naloxone
- C.Vitamin K (phytonadione)
- D.Protamine sulfate✓ Answer
Protamine sulfate is the specific antidote that reverses heparin; vitamin K reverses warfarin.
3. A client is taking digoxin, a cardiac glycoside, for heart failure. Which finding requires the nurse to hold the dose and notify the provider?
- A.Temperature of 37°C (98.6°F)
- B.Respiratory rate of 18 breaths/min
- C.Blood pressure of 130/80 mmHg
- D.Apical heart rate of 52 beats/min✓ Answer
Digoxin slows heart rate, so the dose is held for an apical pulse below 60 beats/min in adults.
4. A client on a loop diuretic (furosemide) should be monitored for which electrolyte imbalance?
- A.Hypercalcemia (high calcium)
- B.Hypokalemia (low potassium)✓ Answer
- C.Hypernatremia (high sodium)
- D.Hyperkalemia (high potassium)
Loop diuretics like furosemide increase potassium excretion, causing hypokalemia.
5. A client taking an ACE inhibitor (angiotensin-converting enzyme inhibitor), such as lisinopril, reports a persistent dry cough. What is the nurse's BEST interpretation?
- A.This is an expected therapeutic effect of the drug
- B.This is a known side effect of ACE inhibitors and should be reported to the provider✓ Answer
- C.This indicates a respiratory infection unrelated to the drug
- D.This means the client is having an anaphylactic reaction
A persistent dry cough is a classic side effect of ACE inhibitors; the provider may switch to an ARB.
6. Before administering an aminoglycoside antibiotic (gentamicin), which two laboratory values are MOST important for the nurse to monitor for toxicity?
- A.PT and INR
- B.Amylase and lipase
- C.AST and ALT (liver enzymes)
- D.BUN and serum creatinine (kidney function)✓ Answer
Aminoglycosides are nephrotoxic and ototoxic, so BUN and creatinine are monitored for kidney injury.
7. A client is receiving intravenous vancomycin. Flushing of the face, neck, and upper body appears during a rapid infusion. What is the nurse's PRIORITY action?
- A.Administer the next dose immediately
- B.Increase the infusion rate to finish faster
- C.Slow the infusion rate✓ Answer
- D.Stop all IV fluids for the day
Rapid vancomycin infusion causes flushing (vancomycin infusion reaction), which is managed by slowing the infusion rate.
8. According to the rights of safe medication administration, what must the nurse do immediately before giving any medication?
- A.Rely on the client's room number alone
- B.Ask a family member to confirm the client's name
- C.Verify the client's identity using two identifiers✓ Answer
- D.Chart the medication as given before administration
The right client is confirmed using two identifiers (e.g., name and date of birth), never the room number alone.
9. A client is started on an opioid analgesic (morphine). Which side effect should the nurse plan to prevent proactively?
- A.Constipation✓ Answer
- B.Diarrhea
- C.Hypertension
- D.Tachypnea
Opioids slow gastrointestinal motility, so a bowel regimen is started to prevent constipation.
10. A client receiving an opioid has a respiratory rate of 8 breaths/min and is difficult to arouse. Which high-alert antidote should the nurse anticipate administering?
- A.Flumazenil
- B.Protamine sulfate
- C.Naloxone✓ Answer
- D.Acetylcysteine
Naloxone is the opioid antagonist that reverses respiratory depression from opioid overdose.
11. A client with type 2 diabetes takes metformin, a biguanide. Which point is MOST important for the nurse to teach?
- A.Expect frequent hypoglycemia when used alone
- B.Stop the drug if any mild nausea occurs
- C.Take the drug only when blood glucose is very high
- D.Hold the drug before procedures using iodinated IV contrast dye✓ Answer
Metformin is held before and after iodinated contrast because of the risk of lactic acidosis from acute kidney injury.
12. A client is prescribed a statin (atorvastatin) for high cholesterol. Which client complaint should the nurse report as a possible sign of a serious adverse effect?
- A.Unexplained muscle pain and weakness✓ Answer
- B.Increased appetite
- C.Occasional sneezing
- D.Mild dry mouth
Statins can cause myopathy and rhabdomyolysis; unexplained muscle pain or weakness must be reported.
13. A client is receiving intravenous potassium chloride, a high-alert medication. Which nursing action is essential for safe administration?
- A.Always dilute it and infuse it slowly using an infusion pump; never give it IV push✓ Answer
- B.Mix it with the client's next intramuscular injection
- C.Administer it undiluted through a peripheral line
- D.Give it as a rapid IV push to correct low potassium quickly
IV potassium chloride must always be diluted and infused slowly via pump; IV push can cause fatal cardiac arrest.
14. A client taking warfarin has an INR of 5.8 with no active bleeding. Which medication should the nurse anticipate administering as the reversal agent?
- A.Protamine sulfate
- B.Vitamin K (phytonadione)✓ Answer
- C.Naloxone
- D.Calcium gluconate
Vitamin K (phytonadione) reverses warfarin by restoring clotting factor synthesis; protamine reverses heparin.
15. A client receiving a continuous IV heparin infusion has an aPTT that is 3.5 times the control value. What is the nurse's PRIORITY action?
- A.Increase the infusion rate
- B.Administer vitamin K
- C.Stop the infusion and notify the provider✓ Answer
- D.Give an additional heparin bolus
A therapeutic heparin aPTT is 1.5–2.5 times control; 3.5 times is dangerously high, so the nurse stops the infusion and notifies the provider.
16. A client on digoxin reports nausea, visual disturbances with yellow-green halos, and has a serum digoxin level of 3.2 ng/mL. How should the nurse interpret this finding?
- A.The level is subtherapeutic and the dose should be increased
- B.These are expected effects requiring no action
- C.These are signs of digoxin toxicity✓ Answer
- D.This indicates an allergic reaction to digoxin
The therapeutic digoxin range is 0.5–2.0 ng/mL; 3.2 ng/mL with nausea and yellow-green vision indicates toxicity; the antidote is digoxin immune Fab.
17. A client with digoxin toxicity also has a serum potassium of 2.9 mEq/L. Why is this combination especially dangerous?
- A.Hypokalemia increases the risk of digoxin toxicity and dysrhythmias✓ Answer
- B.Low potassium protects the heart from digoxin
- C.Potassium has no effect on digoxin
- D.High potassium is the real concern with digoxin
Hypokalemia potentiates digoxin binding to the heart, increasing toxicity and the risk of lethal dysrhythmias.
18. A client is prescribed metoprolol, a beta-blocker. Before administering, which assessment finding would cause the nurse to hold the dose?
- A.Heart rate 88 beats/min
- B.Blood pressure 138/86 mmHg
- C.Heart rate 48 beats/min✓ Answer
- D.Respiratory rate 16 breaths/min
Beta-blockers lower heart rate and blood pressure; a dose is typically held for a pulse below 60 beats/min, such as 48.
19. A nurse is teaching a client with diabetes who takes a beta-blocker (propranolol). Why does the nurse emphasize checking blood glucose closely?
- A.Beta-blockers raise blood glucose to dangerous levels
- B.Beta-blockers can mask the early warning signs of hypoglycemia✓ Answer
- C.Beta-blockers cure diabetes over time
- D.Beta-blockers replace the need for insulin
Beta-blockers blunt sympathetic symptoms such as tachycardia and tremor, masking early hypoglycemia warning signs.
20. A client is started on lisinopril, an ACE inhibitor. Which laboratory value should the nurse monitor for a potentially serious adverse effect?
- A.Serum sodium
- B.Serum calcium
- C.Serum magnesium
- D.Serum potassium✓ Answer
ACE inhibitors reduce aldosterone, causing potassium retention; the nurse monitors serum potassium for hyperkalemia.
21. A client is prescribed spironolactone, a potassium-sparing diuretic. Which teaching point is MOST appropriate?
- A.Use salt substitutes freely to add flavor
- B.Eat large amounts of bananas and oranges daily
- C.Avoid potassium-based salt substitutes and excess high-potassium foods✓ Answer
- D.Take an over-the-counter potassium supplement each morning
Spironolactone retains potassium, so clients must avoid potassium-based salt substitutes and excess high-potassium foods to prevent hyperkalemia.
22. A nurse is preparing to administer regular insulin and NPH insulin as a mixed dose. In what order should the insulins be drawn into the syringe?
- A.Draw up the NPH (cloudy) insulin first, then the regular (clear) insulin
- B.The order does not matter
- C.Never mix these two insulins in one syringe
- D.Draw up the regular (clear) insulin first, then the NPH (cloudy) insulin✓ Answer
Draw the clear (regular) insulin before the cloudy (NPH) — 'clear before cloudy' — to avoid contaminating the regular insulin vial.
23. A client receives regular insulin (a short-acting insulin) subcutaneously at 0800. At approximately what time should the nurse be MOST alert for hypoglycemia due to peak action?
- A.About 15 minutes later (0815)
- B.About 2–4 hours later (1000–1200)✓ Answer
- C.About 12 hours later (2000)
- D.About 24 hours later
Regular (short-acting) insulin peaks about 2–4 hours after subcutaneous injection, when hypoglycemia risk is highest.
24. A client is prescribed insulin glargine (a long-acting basal insulin) once daily. Which statement about this insulin is correct?
- A.It has no pronounced peak and should not be mixed with other insulins✓ Answer
- B.It acts within 15 minutes and peaks in 1 hour
- C.It should always be mixed with regular insulin
- D.It is given IV push for rapid effect
Insulin glargine provides steady, peakless basal coverage and must not be mixed with other insulins or given IV.
25. The provider orders 6 units of regular insulin. The vial is labeled 100 units/mL. How many milliliters should the nurse draw up? (Ideally use an insulin syringe.)
- A.0.06 mL✓ Answer
- B.0.6 mL
- C.6 mL
- D.0.006 mL
Desired/have × volume = 6 units ÷ 100 units/mL × 1 mL = 0.06 mL.
26. A provider orders 250 mg of an antibiotic. The pharmacy supplies a solution of 125 mg per 5 mL. How many milliliters should the nurse administer?
- A.5 mL
- B.2.5 mL
- C.10 mL✓ Answer
- D.12.5 mL
Desired/have × quantity = 250 mg ÷ 125 mg × 5 mL = 2 × 5 = 10 mL.
27. A provider orders 1,000 mL of normal saline IV to infuse over 8 hours using a pump. What rate in mL/hr should the nurse set?
- A.80 mL/hr
- B.125 mL/hr✓ Answer
- C.100 mL/hr
- D.150 mL/hr
Rate = volume ÷ time = 1,000 mL ÷ 8 hr = 125 mL/hr.
28. A provider orders an IV to infuse at 100 mL/hr using tubing with a drop factor of 15 gtt/mL (gravity infusion). What is the correct rate in drops per minute?
- A.15 gtt/min
- B.50 gtt/min
- C.25 gtt/min✓ Answer
- D.30 gtt/min
gtt/min = (100 mL/hr ÷ 60 min) × 15 gtt/mL = 1.667 × 15 = 25 gtt/min.
29. A child weighs 20 kg. The safe dose of a medication is 10 mg/kg/day divided into 2 equal doses. How many milligrams should the nurse give per dose?
- A.200 mg
- B.50 mg
- C.100 mg✓ Answer
- D.20 mg
20 kg × 10 mg/kg/day = 200 mg/day; divided into 2 doses = 100 mg per dose.
30. A client is taking phenytoin, an anticonvulsant, for seizures. The serum phenytoin level is 28 mcg/mL. How should the nurse interpret this value?
- A.It is below the therapeutic range; increase the dose
- B.It is within the therapeutic range; continue as ordered
- C.It is above the therapeutic range, indicating toxicity✓ Answer
- D.The value has no clinical significance
The therapeutic phenytoin range is 10–20 mcg/mL; 28 mcg/mL is toxic, causing nystagmus, ataxia, and slurred speech.
31. A client taking phenytoin should receive which important teaching about a common side effect?
- A.Perform meticulous oral hygiene to reduce gingival hyperplasia✓ Answer
- B.Expect the urine to turn bright blue
- C.Stop the drug abruptly if a rash appears
- D.Double the dose if a seizure occurs
Phenytoin commonly causes gingival hyperplasia, so meticulous oral hygiene and regular dental care are taught; anticonvulsants are never stopped abruptly.
32. A client on lithium for bipolar disorder has a serum lithium level of 2.1 mEq/L with coarse tremors, vomiting, and confusion. What is the nurse's PRIORITY action?
- A.Administer the next scheduled lithium dose
- B.Hold the lithium and notify the provider✓ Answer
- C.Encourage a low-sodium diet
- D.Restrict all fluids immediately
The therapeutic lithium range is 0.6–1.2 mEq/L; 2.1 mEq/L with tremors and confusion signals toxicity, so the nurse holds the dose and notifies the provider.
33. A client is starting lithium therapy. Which teaching about diet and fluids is MOST important to prevent toxicity?
- A.Drastically restrict sodium and water intake
- B.Increase caffeine to promote diuresis
- C.Skip fluids on days the drug is taken
- D.Maintain consistent sodium intake and adequate fluids✓ Answer
Low sodium or dehydration increases lithium reabsorption and toxicity, so clients maintain consistent sodium and adequate fluid intake.
34. A client on a first-generation antipsychotic (haloperidol) develops a high fever, muscle rigidity, altered mental status, and unstable vital signs. Which complication should the nurse suspect?
- A.Neuroleptic malignant syndrome (NMS)✓ Answer
- B.Mild extrapyramidal restlessness
- C.Expected sedation
- D.Simple dehydration
High fever, rigidity, altered mental status, and autonomic instability indicate neuroleptic malignant syndrome, a life-threatening emergency requiring immediate drug discontinuation.
35. A client has been taking oral prednisone, a corticosteroid, for several months. Which instruction is MOST important when the drug is being discontinued?
- A.Stop the drug abruptly once symptoms improve
- B.Taper the dose gradually as prescribed; never stop abruptly✓ Answer
- C.Double the dose the day before stopping
- D.Take the drug on an empty stomach at bedtime
Long-term corticosteroids suppress the adrenal glands; abrupt withdrawal can cause acute adrenal insufficiency, so the dose must be tapered gradually.
36. A client on long-term corticosteroid therapy should be monitored for which set of adverse effects?
- A.Hypoglycemia, weight loss, and hypotension
- B.Hyperglycemia, increased infection risk, and osteoporosis✓ Answer
- C.Bradycardia and hyperkalemia
- D.Improved wound healing and low blood pressure
Corticosteroids raise blood glucose, suppress immunity (masking infection), and cause bone loss, so these effects are monitored.
37. A client uses an albuterol inhaler (a short-acting beta-2 agonist bronchodilator) and a beclomethasone inhaler (an inhaled corticosteroid). In what order should they be used, and why?
- A.Corticosteroid first, then albuterol, to open the airways
- B.Albuterol first, then the corticosteroid, so the airways open before the steroid is delivered✓ Answer
- C.The order does not matter
- D.Both should be taken at the exact same time
Use the bronchodilator (albuterol) first to open the airways, then the corticosteroid, improving steroid deposition in the lungs.
38. A client should be taught to rinse the mouth after using an inhaled corticosteroid (fluticasone). What complication does this prevent?
- A.Oral candidiasis (thrush)✓ Answer
- B.Tooth discoloration only
- C.Loss of taste permanently
- D.Bronchospasm
Inhaled corticosteroids suppress local immunity in the mouth; rinsing after use prevents oral candidiasis (thrush).
39. A client is prescribed theophylline, a bronchodilator with a narrow therapeutic range. The serum level is 25 mcg/mL. Which finding is consistent with toxicity?
- A.Bradycardia and drowsiness
- B.Constipation and hypothermia
- C.No symptoms; this is a normal level
- D.Tachycardia, seizures, and dysrhythmias✓ Answer
The therapeutic theophylline range is 10–20 mcg/mL; 25 mcg/mL causes toxicity with tachycardia, seizures, and dysrhythmias.
40. A client is taking an NSAID (ibuprofen) for chronic arthritis. Which teaching is MOST important to prevent a common adverse effect?
- A.Take the medication with food or milk✓ Answer
- B.Take the medication on an empty stomach
- C.Crush and take it with an antacid only
- D.Take it with an alcoholic beverage
NSAIDs irritate the gastric mucosa and can cause GI bleeding; taking them with food or milk reduces gastric irritation.
41. A client has taken a toxic dose of acetaminophen. Which antidote should the nurse anticipate administering?
- A.Naloxone
- B.Flumazenil
- C.Acetylcysteine (N-acetylcysteine)✓ Answer
- D.Protamine sulfate
Acetylcysteine (N-acetylcysteine) is the antidote for acetaminophen overdose and protects the liver from hepatotoxic metabolites.
42. A nurse is administering an intramuscular injection to an adult using the ventrogluteal site. What needle angle is appropriate for this IM injection?
- A.15 degrees
- B.45 degrees
- C.90 degrees✓ Answer
- D.10 degrees
Intramuscular injections are given at a 90-degree angle; the ventrogluteal site is preferred because it avoids major nerves and vessels.
43. A nurse is administering a subcutaneous injection of enoxaparin (a low-molecular-weight heparin) into the abdomen. Which technique is correct?
- A.Aspirate and vigorously massage the site afterward
- B.Do not aspirate and do not rub the site; give at least 2 inches from the umbilicus✓ Answer
- C.Inject at a 15-degree angle into the muscle
- D.Expel the air bubble from the prefilled syringe before injecting
Enoxaparin is given subcutaneously at least 2 inches from the umbilicus without aspirating or rubbing (to reduce bruising); the air bubble in the prefilled syringe is retained.
44. A client is receiving IV promethazine, a high-alert medication known to cause severe tissue damage if it extravasates. Which nursing action reduces this risk?
- A.Give it as a rapid IV push through a small hand vein
- B.Dilute it and administer slowly through a large-bore, patent IV line✓ Answer
- C.Administer it intra-arterially
- D.Mix it with the client's insulin
IV promethazine is caustic; diluting it and giving it slowly through a large, patent vein reduces the risk of severe extravasation injury.
45. A client is prescribed a tetracycline antibiotic (doxycycline). Which teaching is MOST important?
- A.Take it with milk or antacids to protect the stomach
- B.Expect the medication to turn the urine red
- C.Take a double dose if a dose is missed
- D.Avoid it during pregnancy and use sun protection due to photosensitivity✓ Answer
Tetracyclines cause photosensitivity and stain developing teeth, so they are avoided in pregnancy and young children, and sun protection is advised; dairy and antacids reduce absorption.
46. A client taking a monoamine oxidase inhibitor (MAOI) for depression must avoid tyramine-rich foods. Which food should the nurse teach the client to avoid?
- A.Fresh apples
- B.White rice
- C.Aged cheese and cured meats✓ Answer
- D.Plain water
Tyramine-rich foods such as aged cheese and cured meats can trigger a hypertensive crisis when combined with MAOIs.
47. A client on a selective serotonin reuptake inhibitor (SSRI, sertraline) is also given tramadol. The nurse monitors for which serious drug interaction?
- A.Hypoglycemia
- B.Metabolic alkalosis
- C.Deep vein thrombosis
- D.Serotonin syndrome✓ Answer
Combining serotonergic drugs (an SSRI plus tramadol) can cause serotonin syndrome: agitation, hyperthermia, tremor, and hyperreflexia.
48. A nurse prepares to give a medication ordered as '0800 with the 'right time' in mind. The client is scheduled for surgery and is NPO. What is the nurse's BEST action?
- A.Give all oral medications with a large glass of water
- B.Clarify with the provider which medications to hold or give before surgery✓ Answer
- C.Skip all medications without notifying anyone
- D.Give the medications rectally instead
For an NPO surgical client, the nurse clarifies with the provider which medications to hold or give (some, like certain cardiac drugs, may be given with a sip of water) rather than assuming.
49. A provider writes a medication order using a prohibited abbreviation, 'U' for units, that could be misread. According to safe medication practice, what should the nurse do?
- A.Interpret the order and administer based on best guess
- B.Contact the provider to clarify and have the order rewritten with 'units' spelled out✓ Answer
- C.Ask another nurse to guess the intended dose
- D.Document the dose as unclear and give a standard amount
'U' is on the 'Do Not Use' list because it can be misread as a zero; the nurse must contact the provider to clarify and have 'units' written out.
Practice questions based on the NCSBN NCLEX-RN test plan. Not affiliated with NCSBN and not medical advice — always follow your program and current clinical guidelines. About the NCLEX →