Pharmacology – RN Practice Questions

These practice questions are written at NCLEX-RN complexity: multi-step clinical reasoning, prioritization, intravenous and titrated medications, and complex interactions. Options are numbered in the order A, B, C, D, E. Answers are given with both the number and the letter.

Question 1

A client with a pulmonary embolism is receiving a continuous intravenous heparin infusion. The 0600 aPTT result is 96 seconds, and the control value is 30 seconds. The client has no active bleeding. Which action should the nurse take first?

1. Continue the infusion at the current rate and recheck the aPTT in 6 hours
2. Stop the infusion and notify the provider, anticipating a rate reduction per protocol
3. Administer protamine sulfate 25 mg intravenously
4. Request an order for a platelet count and fresh frozen plasma

Answer: 2 (B) Stop the infusion and notify the provider, anticipating a rate reduction per protocol.

Rationale: The therapeutic aPTT target for heparin is generally 1.5 to 2.5 times the control, which is 45 to 75 seconds when the control is 30 seconds. An aPTT of 96 seconds is supratherapeutic and places the client at bleeding risk, so the nurse holds the infusion and follows the institutional heparin protocol, which typically directs a brief hold and a rate decrease. Option 1 leaves the client supratherapeutic. Option 3 is premature: protamine sulfate is the antidote but is reserved for significant bleeding or life-threatening overdose, not an isolated elevated aPTT in a client who is not bleeding. Option 4 addresses a different problem; a platelet count is appropriate to screen for heparin-induced thrombocytopenia but is not the first action, and fresh frozen plasma does not reverse heparin.

Question 2

A client with heart failure takes digoxin 0.25 mg daily and furosemide 40 mg twice daily. The client reports nausea, anorexia, and seeing yellow-green halos around lights. Vital signs show an apical pulse of 52 and regular. Which laboratory value should the nurse review first?

1. Serum sodium
2. Serum potassium
3. Serum albumin
4. Serum calcium

Answer: 2 (B) Serum potassium.

Rationale: The client is describing classic digoxin toxicity. Hypokalemia, a very common effect of loop diuretics such as furosemide, potentiates digoxin binding at the sodium-potassium ATPase pump and precipitates toxicity even when the digoxin level is within the usual reference range of 0.5 to 2.0 ng/mL. Potassium is therefore the highest priority value. Sodium, albumin, and calcium can influence drug handling in general, and severe hypercalcemia can worsen digoxin toxicity, but potassium is the immediate and far more common culprit in this scenario, and it is directly correctable.

Question 3

Select all that apply. The nurse is discharging a client newly prescribed warfarin for atrial fibrillation. Which statements by the client indicate correct understanding?

1. "I will use an electric razor and a soft toothbrush."
2. "I will completely stop eating green leafy vegetables."
3. "I will call my provider if my stools look black and tarry."
4. "I will take ibuprofen for my arthritis pain instead of acetaminophen."
5. "I will tell any new provider or dentist that I take a blood thinner."
6. "I will have my INR checked as scheduled even if I feel fine."

Answer: 1, 3, 5, and 6 (A, C, E, F).

Rationale: Options 1, 3, 5, and 6 are correct bleeding precautions and monitoring behaviors. Option 2 is wrong because the teaching is consistent intake of vitamin K containing foods, not elimination; erratic intake, in either direction, destabilizes the INR. Option 4 is wrong because NSAIDs such as ibuprofen add antiplatelet effect and gastrointestinal mucosal injury on top of anticoagulation and markedly raise bleeding risk; acetaminophen within recommended limits is generally the preferred analgesic, though high sustained doses can also elevate the INR and warrant monitoring.

Question 4

A client is receiving intravenous vancomycin. Fifteen minutes into the infusion, the nurse observes flushing and erythema over the face, neck, and upper chest, with mild pruritus. Blood pressure is 104/62 and the airway is clear with no wheezing or stridor. Which action should the nurse take first?

1. Stop the infusion and document a vancomycin allergy in the chart
2. Administer epinephrine 0.3 mg intramuscularly
3. Stop the infusion, notify the provider, and anticipate restarting at a slower rate with an antihistamine
4. Increase the infusion rate to complete the dose more quickly

Answer: 3 (C) Stop the infusion, notify the provider, and anticipate restarting at a slower rate with an antihistamine.

Rationale: This is the vancomycin infusion reaction, a direct histamine release phenomenon caused by rapid infusion, not an IgE-mediated allergy. Management is to stop or slow the infusion, treat with an antihistamine as ordered, and resume over at least 60 minutes or longer. Option 1 mislabels the event and could inappropriately deny the client a needed antibiotic in the future. Option 2 is treatment for anaphylaxis, and there is no airway compromise, hypotension of that severity, or systemic collapse here. Option 4 would worsen the reaction, since rate is the cause.

Question 5

A client in septic shock is receiving norepinephrine through a peripheral intravenous catheter in the forearm while central access is being obtained. The nurse notes blanching, coolness, and swelling around the insertion site. After stopping the infusion and disconnecting the tubing while leaving the catheter in place, which intervention should the nurse anticipate?

1. Applying a warm compress and elevating the extremity only
2. Infiltrating the site with phentolamine as ordered
3. Flushing the catheter with 10 mL of normal saline to confirm patency
4. Applying nitroglycerin ointment to the opposite extremity

Answer: 2 (B) Infiltrating the site with phentolamine as ordered.

Rationale: Extravasation of a potent vasoconstrictor produces intense local vasoconstriction and can cause tissue necrosis. Phentolamine, an alpha-adrenergic blocker, is infiltrated into the affected area to reverse the vasoconstriction and restore perfusion. Option 1 alone is insufficient for a vasoconstrictor extravasation. Option 3 is contraindicated because flushing would push more drug into the tissue. Option 4 is wrong in site; topical nitroglycerin is sometimes used over the affected area, not the opposite extremity.

Question 6

A client has a serum potassium of 2.8 mEq/L. The provider orders potassium chloride 40 mEq. Which order should the nurse question?

1. Potassium chloride 40 mEq in 500 mL normal saline intravenously over 4 hours through a peripheral line
2. Potassium chloride 40 mEq orally in divided doses with food
3. Potassium chloride 40 mEq intravenous push over 5 minutes
4. Potassium chloride 40 mEq in 250 mL normal saline through a central line over 4 hours with continuous cardiac monitoring

Answer: 3 (C) Potassium chloride 40 mEq intravenous push over 5 minutes.

Rationale: Concentrated potassium chloride is never given by intravenous push; doing so causes fatal cardiac arrest. Potassium must always be diluted and infused by pump, generally not faster than 10 mEq per hour peripherally, with higher rates only through central access in a monitored setting per policy. Options 1, 2, and 4 are all acceptable routes and rates. The nurse should also verify adequate urine output before administering potassium.

Question 7

A client in diabetic ketoacidosis is receiving a regular insulin infusion at 7 units per hour and 0.9 percent sodium chloride. The point-of-care glucose has fallen from 620 mg/dL to 245 mg/dL, and the anion gap remains elevated with ketones still present. Which action should the nurse anticipate?

1. Stopping the insulin infusion immediately
2. Adding dextrose to the intravenous fluid and continuing the insulin infusion
3. Switching to subcutaneous insulin glargine and stopping all intravenous fluids
4. Doubling the insulin infusion rate to clear the ketones faster

Answer: 2 (B) Adding dextrose to the intravenous fluid and continuing the insulin infusion.

Rationale: In diabetic ketoacidosis the endpoint of insulin therapy is closure of the anion gap and clearance of ketosis, not normalization of glucose. When the glucose falls to roughly 200 to 250 mg/dL, dextrose is added to the fluid so that the insulin infusion can continue safely without producing hypoglycemia. Option 1 would allow ketogenesis to resume. Option 3 is premature; the transition to subcutaneous insulin occurs after the gap closes, and overlap with the infusion is required. Option 4 risks hypoglycemia and hypokalemia without benefit.

Question 8

A client with chest pain is admitted for a nitroglycerin infusion. During the medication history, the client states he took sildenafil approximately 12 hours ago. Which action is the priority?

1. Start the nitroglycerin infusion at the lowest ordered rate and monitor blood pressure
2. Hold the nitroglycerin and notify the provider immediately
3. Administer the nitroglycerin with a normal saline bolus to prevent hypotension
4. Give sublingual nitroglycerin instead of the infusion

Answer: 2 (B) Hold the nitroglycerin and notify the provider immediately.

Rationale: Nitrates in any form are contraindicated within roughly 24 hours of sildenafil and roughly 48 hours of tadalafil. Combining them causes profound, refractory hypotension and cardiovascular collapse. The nurse holds the drug and communicates with the provider so an alternative anti-ischemic strategy can be chosen. Options 1, 3, and 4 all deliver a nitrate and are unsafe; the route does not remove the interaction, and a fluid bolus does not reliably prevent the hypotension.

Question 9

A client taking sertraline is started on tramadol for acute back pain. Two days later the client presents with agitation, diaphoresis, a temperature of 38.9 degrees Celsius, tremor, hyperreflexia, and inducible ankle clonus. Which condition should the nurse suspect, and what is the priority action?

1. Neuroleptic malignant syndrome; administer an additional dose of sertraline
2. Anticholinergic toxicity; administer physostigmine
3. Serotonin syndrome; stop the serotonergic agents and notify the provider
4. Acute dystonic reaction; administer diphenhydramine and continue both drugs

Answer: 3 (C) Serotonin syndrome; stop the serotonergic agents and notify the provider.

Rationale: The combination of an SSRI and tramadol, both serotonergic, with hyperthermia, autonomic instability, and neuromuscular hyperactivity, especially clonus and hyperreflexia, is characteristic of serotonin syndrome. The priority is to discontinue the offending agents and provide supportive care including cooling and benzodiazepines as ordered. Option 1 is wrong on both counts: neuroleptic malignant syndrome features lead-pipe rigidity and hyporeflexia rather than clonus, and adding sertraline would worsen the syndrome. Option 2 does not fit, since anticholinergic toxicity produces dry skin rather than diaphoresis and normal reflexes. Option 4 misidentifies the syndrome and continues the causative drugs.

Question 10

A client maintained on lithium for bipolar disorder is newly prescribed hydrochlorothiazide for hypertension. Which instruction is most important for the nurse to provide?

1. "Reduce your daily fluid intake to less than one liter."
2. "Follow a low sodium diet while taking both drugs."
3. "Report nausea, vomiting, diarrhea, coarse tremor, or unsteady walking right away, and keep your lithium level appointments."
4. "Take an NSAID such as naproxen if you develop a headache from the new medication."

Answer: 3 (C) Report nausea, vomiting, diarrhea, coarse tremor, or unsteady walking right away, and keep your lithium level appointments.

Rationale: Thiazide diuretics increase renal reabsorption of lithium and raise the serum level, so the client must recognize early toxicity and have levels monitored more closely. The therapeutic range is roughly 0.6 to 1.2 mEq/L, and levels above 1.5 mEq/L are toxic. Option 1 is dangerous because dehydration concentrates lithium. Option 2 is dangerous because sodium restriction increases lithium reabsorption; intake should be adequate and consistent. Option 4 is wrong because NSAIDs also raise lithium levels.

Question 11

The nurse on a medical unit receives report on four clients. Which client should the nurse assess first?

1. A client on a heparin infusion whose platelet count has fallen from 240,000 to 88,000 per microliter since admission five days ago
2. A client on furosemide whose morning weight is down 1.4 kilograms
3. A client on metformin scheduled for a computed tomography scan with contrast tomorrow
4. A client on levothyroxine who reports taking the dose with breakfast

Answer: 1 (A) The client on a heparin infusion with a platelet count that has fallen from 240,000 to 88,000 per microliter since admission five days ago.

Rationale: A drop of more than 50 percent in the platelet count occurring 5 to 10 days after heparin exposure is highly suspicious for heparin-induced thrombocytopenia, a prothrombotic emergency in which the client is at risk for limb-threatening and life-threatening thrombosis. All heparin, including flushes and coated catheters, must be stopped and a nonheparin anticoagulant substituted. Option 2 is an expected diuretic response. Option 3 requires action, holding metformin around contrast administration, but that action is not needed until tomorrow. Option 4 is a teaching opportunity because levothyroxine should be taken on an empty stomach, but it is not urgent.

Question 12

Select all that apply. Which situations require an independent double check by a second qualified clinician according to standard high-alert medication practice?

1. Programming a continuous insulin infusion pump
2. Administering a scheduled oral multivitamin
3. Initiating a patient-controlled analgesia pump with hydromorphone
4. Administering a weight-based heparin bolus
5. Administering intravenous chemotherapy
6. Applying a nonmedicated hydrocolloid dressing

Answer: 1, 3, 4, and 5 (A, C, D, E).

Rationale: Insulin, opioids delivered by patient-controlled analgesia, anticoagulants, and chemotherapy are all high-alert categories in which errors cause severe or fatal harm, so an independent double check of the drug, concentration, dose, rate, pump programming, and client identity is standard. An oral multivitamin, option 2, and a dressing, option 6, are not high-alert and do not require a second verifier. The check must be genuinely independent, meaning the second clinician verifies without being told the expected values.

Question 13

A client arrives 2 hours after the onset of stroke symptoms, and computed tomography shows no hemorrhage. Which finding would most strongly contraindicate alteplase administration?

1. Blood glucose of 142 mg/dL
2. Blood pressure of 196/118 mmHg that remains elevated despite treatment
3. Age of 78 years
4. National Institutes of Health Stroke Scale score of 12

Answer: 2 (B) Blood pressure of 196/118 mmHg that remains elevated despite treatment.

Rationale: Uncontrolled hypertension above approximately 185/110 mmHg must be lowered before alteplase is given, and if it cannot be controlled, the drug is withheld because of intracranial hemorrhage risk. Option 1 is a normal to mildly elevated glucose and is not a contraindication; profound hypoglycemia or marked hyperglycemia would prompt reevaluation of the diagnosis. Option 3 is not an absolute contraindication, since advanced age alone does not exclude treatment. Option 4 describes a moderate deficit, which supports rather than contraindicates treatment.

Question 14

A client has been taking amiodarone for six months for atrial fibrillation. Which new finding requires the most immediate provider notification?

1. Blue-gray discoloration of the skin on the face
2. A nonproductive cough with progressive exertional dyspnea and new bibasilar crackles
3. A thyroid stimulating hormone level of 6.2 microunits per milliliter
4. Corneal microdeposits noted on a routine eye examination

Answer: 2 (B) A nonproductive cough with progressive exertional dyspnea and new bibasilar crackles.

Rationale: Amiodarone pulmonary toxicity, which can progress to irreversible fibrosis, is the most dangerous adverse effect of the drug and requires prompt evaluation and usually discontinuation. Option 1 is a cosmetic photosensitivity-related change that should be reported but is not urgent. Option 3 reflects amiodarone-induced hypothyroidism, which is common, expected on monitoring, and treatable with levothyroxine. Option 4 is very common, generally asymptomatic, and monitored rather than treated emergently.

Question 15

A client with severe preeclampsia is receiving an intravenous magnesium sulfate infusion. The nurse finds absent patellar deep tendon reflexes, a respiratory rate of 10, and urine output of 20 mL over the last hour. Which is the correct sequence of nursing actions?

1. Increase the infusion rate, then notify the provider
2. Stop the infusion, administer calcium gluconate as ordered, and notify the provider
3. Administer naloxone, then stop the infusion
4. Continue the infusion and recheck reflexes in one hour

Answer: 2 (B) Stop the infusion, administer calcium gluconate as ordered, and notify the provider.

Rationale: Loss of deep tendon reflexes is the earliest reliable sign of magnesium toxicity, followed by respiratory depression, oliguria, and eventually cardiac arrest. Magnesium is renally cleared, so falling urine output accelerates accumulation. The nurse stops the infusion first, then gives the antidote, calcium gluconate, and notifies the provider. Option 1 worsens the toxicity. Option 3 is wrong because naloxone reverses opioids, not magnesium. Option 4 delays treatment of an evolving emergency.

This page is independent study material for nursing licensure exam preparation. NCLEX-RN® and NCLEX-PN® are registered trademarks of the National Council of State Boards of Nursing (NCSBN). This content is not produced, reviewed, or endorsed by NCSBN. Always verify clinical information against current facility policy, drug references, and your nursing program's curriculum before applying it in practice.