NAPLEX Quiz: Contraindications And Precautions

What this quiz covers

This quiz focuses on Contraindications And Precautions, giving you a quick way to practice the rules, question types, and explanations that matter most for NAPLEX.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Nitrofurantoin 100 mg by mouth twice daily for 5 days
2. Cephalexin 500 mg by mouth four times daily for 5–7 days
3. Fosfomycin tromethamine 3 g by mouth once
4. Trimethoprim/sulfamethoxazole 160/800 mg by mouth twice daily for 3 days (correct answer)

Explanation: This question tests knowledge of antibiotic safety during pregnancy, specifically first-trimester contraindications. The patient is 10 weeks pregnant with uncomplicated cystitis requiring antibiotic therapy. Trimethoprim/sulfamethoxazole (choice D) is contraindicated in the first trimester due to trimethoprim's antifolate activity, which increases the risk of neural tube defects and other congenital anomalies. Nitrofurantoin (choice A) is safe after the first trimester but should be used with caution in early pregnancy. Cephalexin (choice B) is a pregnancy category B antibiotic and represents the safest choice for this patient. Fosfomycin (choice C) has limited pregnancy data but is generally considered safe. The clinical pearl is that folate antagonists like trimethoprim should be avoided in the first trimester, and beta-lactam antibiotics like cephalexin are preferred for UTI treatment during pregnancy.

Question 2

1. Monitor for respiratory depression and excessive sedation; consider a lower dose or alternative due to COPD and age (correct answer)
2. Monitor international normalized ratio (INR) weekly due to increased bleeding risk
3. Add potassium supplementation to prevent hypokalemia
4. Avoid grapefruit juice due to risk of hypertensive crisis

Explanation: This question tests recognition of benzodiazepine precautions in patients with respiratory compromise. The patient has COPD requiring home oxygen, indicating severe respiratory impairment, and is prescribed diazepam 10 mg three times daily, which is a high dose of a long-acting benzodiazepine. The primary concern (choice A) is respiratory depression and excessive sedation, as benzodiazepines depress the respiratory drive and can precipitate respiratory failure in COPD patients, especially at high doses in elderly patients. Choice B incorrectly suggests INR monitoring, which isn't relevant to diazepam. Choice C about potassium supplementation and choice D about grapefruit juice interactions are not applicable to benzodiazepines. The clinical pearl is that benzodiazepines should be used with extreme caution in COPD patients, starting with the lowest effective dose of shorter-acting agents, and avoiding long-acting benzodiazepines like diazepam when possible.

Question 3

1. Doxycycline 100 mg orally twice daily for 7 days
2. Amoxicillin-clavulanate 875/125 mg orally twice daily for 7 days
3. Trimethoprim-sulfamethoxazole 160/800 mg orally twice daily for 7 days (correct answer)
4. Cefpodoxime 200 mg orally twice daily for 7 days

Explanation: This question tests contraindications for antibiotics in patients on QT-prolonging antiarrhythmics. The key patient-specific factor is the patient's dofetilide therapy for atrial fibrillation, which increases torsades de pointes risk. Trimethoprim-sulfamethoxazole is contraindicated because it can prolong the QT interval, potentiating arrhythmias with dofetilide. Doxycycline, amoxicillin-clavulanate, and cefpodoxime do not significantly affect QT. These options are acceptable alternatives post-allergy consideration. A pearl is to review QT risks before prescribing in arrhythmia patients, following AHA guidelines. Emphasize avoiding additive QT-prolonging agents to mitigate cardiac events.

Question 4

1. Semaglutide 0.25 mg subcutaneously once weekly (titration planned) (correct answer)
2. Empagliflozin 10 mg orally daily
3. Sitagliptin 100 mg orally daily
4. Pioglitazone 15 mg orally daily

Explanation: This question assesses contraindications for antidiabetic agents based on family history. The key patient-specific factor is the family history of medullary thyroid carcinoma, raising concerns for C-cell tumors. Semaglutide is contraindicated or should be avoided because GLP-1 agonists carry a boxed warning for thyroid C-cell tumors in patients with personal or family history of MTC or MEN2. Empagliflozin, sitagliptin, and pioglitazone lack this risk. The distractors are appropriate for glycemic control. A pearl is to screen for MTC history before GLP-1 initiation, following ADA guidelines. Decision-making should include genetic risk assessment to avoid promoting rare malignancies.

Question 5

1. Nitrofurantoin 100 mg orally twice daily for 5 days
2. Ciprofloxacin 250 mg orally twice daily for 3 days
3. TMP-SMX 160/800 mg orally twice daily for 3 days (correct answer)
4. Fosfomycin tromethamine 3 g orally once

Explanation: This question tests drug interactions between antibiotics and mood stabilizers in urinary tract infection treatment. The key patient-specific factor is the patient's lithium therapy for bipolar disorder, which can lead to toxicity with certain drugs. Trimethoprim-sulfamethoxazole is contraindicated due to its potential to decrease lithium clearance, increasing toxicity risk per interaction data. Nitrofurantoin, ciprofloxacin, and fosfomycin lack significant lithium interactions. These options are suboptimal only if resistance is present but not contraindicated. A pearl is to check for interactions with narrow therapeutic index drugs like lithium, following psychiatric guidelines. Decision-making should prioritize avoiding combinations that alter renal handling of lithium.

Question 6

1. Topical diclofenac 1% gel: apply 4 g to the knee up to four times daily
2. Acetaminophen 650 mg by mouth every 6 hours as needed (maximum 3,000 mg/day)
3. Ibuprofen 600 mg by mouth three times daily with food (correct answer)
4. Intra-articular corticosteroid injection administered in clinic

Explanation: This question evaluates NSAID contraindications in patients with cardiovascular and renal disease. The patient has heart failure with reduced ejection fraction, CKD stage 3a, and is on multiple medications that affect renal function and potassium levels, with a current potassium of 5.1 mEq/L (upper limit of normal). Ibuprofen (choice C) is contraindicated due to multiple factors: NSAIDs worsen heart failure by promoting sodium and water retention, reduce renal function in CKD patients, and can cause hyperkalemia, especially when combined with ACE inhibitors/ARBs and potassium-sparing diuretics like spironolactone. Topical diclofenac (choice A) has minimal systemic absorption and is safer. Acetaminophen (choice B) lacks these cardiovascular and renal effects. Intra-articular corticosteroids (choice D) provide local relief without systemic NSAID exposure. The key principle is that oral NSAIDs are contraindicated in heart failure and should be avoided in CKD patients on RAAS inhibitors due to cumulative risks.

Question 7

1. No adjustment is needed; use the ordered regimen because hepatic function is normal
2. Avoid colchicine and use allopurinol 300 mg daily for the acute flare instead
3. Reduce colchicine to a single 0.6 mg dose; do not repeat the course for at least 2 weeks in severe renal impairment (correct answer)
4. Increase colchicine to 0.6 mg three times daily because eGFR is low

Explanation: This question evaluates the appropriate dosing adjustment of colchicine in severe renal impairment. The patient has an eGFR of 18 mL/min/1.73 m², indicating severe renal impairment (CKD stage 4), which significantly reduces colchicine clearance and increases toxicity risk. The correct adjustment (choice C) is to reduce colchicine to a single 0.6 mg dose without repeating for at least 2 weeks, as recommended by FDA guidelines for severe renal impairment. Choice A is incorrect because normal hepatic function doesn't negate the need for renal adjustment. Choice B incorrectly suggests using allopurinol for acute flares, when it's only for chronic management. Choice D dangerously suggests increasing the dose when reduction is needed. The key principle is that colchicine requires significant dose reduction in severe renal impairment due to decreased clearance and increased risk of life-threatening toxicity.

Question 8

1. Tramadol 50 mg orally every 6 hours as needed (correct answer)
2. Acetaminophen 650 mg orally every 6 hours as needed
3. Topical diclofenac 1% gel applied four times daily to affected area
4. Naproxen 220 mg orally every 12 hours as needed with food

Explanation: This question tests contraindications for analgesics in patients on monoamine oxidase inhibitors. The key patient-specific factor is the patient's phenelzine (MAOI) therapy, increasing serotonin syndrome risk. Tramadol is contraindicated because its serotonergic effects combined with MAOIs can precipitate serotonin syndrome, including agitation and hyperthermia. Acetaminophen, topical diclofenac, and naproxen lack serotonergic activity. The distractors are safer for pain management. A pearl is to avoid serotonergic agents within 14 days of MAOIs, per psychiatric guidelines. Decision frameworks should include interaction screening to prevent neurologic crises.

Question 9

1. Dextromethorphan 20 mg orally every 6 hours as needed
2. Diphenhydramine 25 mg orally at bedtime as needed (correct answer)
3. Guaifenesin 600 mg orally every 12 hours as needed
4. Honey 1 tablespoon orally as needed for cough (if no contraindications)

Explanation: This question evaluates contraindications for cough suppressants in patients with urinary retention risks. The key patient-specific factor is the patient's benign prostatic hyperplasia with urinary retention episodes, exacerbated by anticholinergics. Diphenhydramine is contraindicated because its anticholinergic effects can worsen urinary retention and cause acute complications. Dextromethorphan lacks anticholinergic activity; guaifenesin is an expectorant without retention risks; honey is a non-pharmacologic option. The distractors are safer alternatives without similar side effects. A pearl is to assess for BPH before recommending anticholinergic OTCs, per urology guidelines. Emphasize guideline-based selection of agents with minimal anticholinergic burden in elderly or at-risk males.

Question 10

1. Acetaminophen 325 mg orally every 6 hours as needed (do not exceed 2,000 mg/day without provider input)
2. Ibuprofen 400 mg orally every 6 hours as needed with food (correct answer)
3. Topical menthol/methyl salicylate applied to back as directed
4. Nonpharmacologic heat therapy as needed

Explanation: This question assesses bleeding risk contraindications for OTC analgesics in anticoagulated patients. The key patient-specific factor is the patient's warfarin therapy with elevated INR 3.1, heightening hemorrhage potential. Ibuprofen is contraindicated or should be avoided because NSAIDs inhibit platelet function and increase bleeding risk with anticoagulants. Acetaminophen is safer at limited doses; topical menthol/methyl salicylate has lower systemic effects; heat therapy is non-pharmacologic. The distractors pose less bleeding threat. A pearl is to monitor INR with any analgesic addition, following anticoagulation guidelines. Emphasize selecting low-risk options to maintain therapeutic INR without complications.

Question 11

1. Sildenafil 50 mg orally as needed (maximum once daily) (correct answer)
2. Tadalafil 5 mg orally once daily
3. Nitroglycerin 0.4 mg sublingual as needed for chest pain
4. Acetaminophen 650 mg orally every 6 hours as needed for headache

Explanation: This question evaluates contraindications for PDE5 inhibitors in patients using nitrates. The key patient-specific factor is the patient's nitroglycerin use for stable angina, which can cause severe hypotension when combined with certain drugs. Sildenafil is contraindicated because PDE5 inhibitors potentiate nitrate-induced vasodilation, leading to life-threatening hypotension. Tadalafil has similar risks but is not the selected choice; nitroglycerin is current therapy; acetaminophen is unrelated. The distractors do not share the interaction severity. A clinical pearl is to counsel on nitrate-PDE5 spacing, per ACC guidelines. Decision-making should prioritize avoiding hypotensive synergies in cardiovascular patients.

Question 12

1. Levofloxacin 750 mg orally once daily with no renal adjustment
2. Levofloxacin 750 mg orally once, then 750 mg orally every 48 hours (renal adjustment) (correct answer)
3. Levofloxacin is contraindicated at CrCl 22 mL/min and must not be used
4. Levofloxacin 250 mg orally once daily only (no loading dose needed)

Explanation: This question assesses renal dose adjustments for antibiotics in pyelonephritis treatment. The key patient-specific factor is the patient's CKD stage 4 with CrCl 22 mL/min, necessitating dose reduction to prevent toxicity. Administering levofloxacin 750 mg once, then every 48 hours is the best adjustment per manufacturer guidelines for CrCl 20-49 mL/min to maintain efficacy while reducing accumulation. No adjustment risks overdose; complete contraindication is inaccurate as adjusted use is allowed; lower daily dose without loading may underexpose initially. The distractors could lead to subtherapeutic or toxic levels. A pearl is to use Cockcroft-Gault for antibiotic dosing, following IDSA guidelines. Emphasize renal function-based adjustments to optimize outcomes and safety.

Question 13

1. Denosumab 60 mg subcutaneously every 6 months
2. Alendronate 70 mg orally once weekly (correct answer)
3. Calcium carbonate 500 mg orally twice daily with meals
4. Vitamin D3 1,000 units orally daily

Explanation: This question evaluates contraindications for osteoporosis treatments in esophageal disorders. The key patient-specific factor is the patient's severe esophageal stricture and GERD, raising irritation risks. Alendronate is contraindicated because oral bisphosphonates can cause esophagitis and ulcers, especially with swallowing difficulties. Denosumab is injectable without GI effects; calcium and vitamin D are supportive without contraindications. The distractors are appropriate alternatives. A pearl is to ensure upright posture post-bisphosphonate dosing, per endocrinology guidelines. Emphasize selecting non-oral therapies in GI-compromised patients to avoid erosions.

Question 14

1. Cyclobenzaprine 10 mg orally three times daily as needed (correct answer)
2. Acetaminophen 650 mg orally every 6 hours as needed (maximum 3,000 mg/day)
3. Topical lidocaine 4% patch applied up to 12 hours/day
4. Physical therapy referral and stretching exercises

Explanation: This question evaluates age-related precautions for muscle relaxants in elderly patients. The key patient-specific factor is the patient's age of 74 years with Alzheimer disease and fall history, increasing anticholinergic and sedation risks. Cyclobenzaprine should be avoided because it has high anticholinergic burden, exacerbating fall risk and cognitive impairment in the elderly. Acetaminophen is safe for pain; topical lidocaine has minimal systemic effects; physical therapy is non-pharmacologic. The distractors lack similar risks. A pearl is to use Beers Criteria to avoid high-risk medications in older adults. Emphasize minimizing anticholinergics to prevent falls and delirium.

Question 15

1. Prednisone 30 mg orally daily for 5 days
2. Colchicine 1.2 mg orally once, then 0.6 mg 1 hour later
3. Indomethacin 50 mg orally three times daily with food (correct answer)
4. Intra-articular corticosteroid injection (if feasible)

Explanation: This question examines contraindications for acute gout treatments in patients with advanced renal impairment. The key patient-specific factor is the patient's chronic kidney disease stage 4 with CrCl 18 mL/min, increasing toxicity risks. Indomethacin is contraindicated because NSAIDs can further impair renal function and cause acute kidney injury in severe CKD. Prednisone is safe for short-term use; colchicine requires dose adjustment but is not contraindicated; intra-articular steroids are appropriate if feasible. The distractors are suboptimal only if ineffective, but indomethacin poses the highest renal risk. A pearl is to calculate CrCl before prescribing gout therapies, per American College of Rheumatology guidelines. Emphasize avoiding nephrotoxic agents in CKD to prevent progression to dialysis.

Question 16

1. Warfarin dosed to maintain INR 2.0–3.0
2. Apixaban 5 mg orally twice daily (correct answer)
3. Unfractionated heparin infusion per protocol
4. Enoxaparin 1 mg/kg subcutaneously every 12 hours (bridge therapy)

Explanation: This question tests contraindications for anticoagulants in patients with mechanical heart valves, based on evidence from clinical trials. The key patient-specific factor is the patient's mechanical aortic valve replacement, which requires vitamin K antagonist therapy. Apixaban is contraindicated because direct oral anticoagulants (DOACs) like apixaban have shown increased thromboembolic and bleeding risks in mechanical valve patients compared to warfarin. Warfarin is appropriate with INR monitoring; unfractionated heparin and enoxaparin are suitable for bridging in specific scenarios. The other options are not contraindicated and may be used per guidelines. A clinical pearl is to reserve DOACs for non-valvular atrial fibrillation, following American Heart Association recommendations. Decision-making should prioritize evidence-based anticoagulation to minimize stroke and valve thrombosis risks.

Question 17

1. Topical diclofenac 1% gel applied to knee four times daily
2. Acetaminophen 650 mg orally every 6 hours as needed (maximum 3,000 mg/day)
3. Ibuprofen 600 mg orally three times daily with food (correct answer)
4. Capsaicin 0.025% cream applied to knee three times daily

Explanation: This question assesses contraindications for analgesics in osteoarthritis management, focusing on comorbidities like heart failure and renal impairment. The key patient-specific factor is the patient's heart failure with reduced ejection fraction and chronic kidney disease stage 3, which heighten risks of fluid retention and renal deterioration. Ibuprofen is contraindicated because systemic NSAIDs can exacerbate heart failure through sodium retention and worsen renal function in CKD patients. Topical diclofenac is acceptable with minimal systemic absorption; acetaminophen is safe and preferred for its lack of renal or cardiac effects; capsaicin is a topical option without contraindications here. Other choices are suboptimal only if they fail to provide adequate pain relief, but ibuprofen poses the greatest risk. A clinical pearl is to prioritize non-NSAID options in patients with heart failure or CKD, per American College of Cardiology guidelines. Decision-making should emphasize avoiding agents that impair renal perfusion or promote fluid overload in vulnerable populations.

Question 18

1. Azelaic acid 15% gel applied twice daily
2. Isotretinoin 40 mg orally daily (correct answer)
3. Benzoyl peroxide 5% wash used once daily
4. Clindamycin 1% topical solution applied twice daily

Explanation: This question evaluates contraindications for acne treatments during pregnancy, highlighting teratogenic risks. The key patient-specific factor is the patient's pregnancy at 10 weeks gestation, which necessitates avoiding category X medications. Isotretinoin is contraindicated because it is highly teratogenic, causing severe birth defects like craniofacial and cardiac abnormalities. Azelaic acid is safe (category B) for topical use; benzoyl peroxide is acceptable with low systemic absorption; clindamycin topical is generally safe without pregnancy-related risks. The distractors are incorrect as they do not carry the same level of fetal harm. A transferable pearl is to always confirm pregnancy status before prescribing retinoids, adhering to iPLEDGE program requirements. Guideline-based decisions from the American Academy of Dermatology emphasize risk-benefit assessment in pregnant patients to prevent avoidable teratogenicity.

Question 19

1. Ampicillin 75 mg/kg/day intravenously divided every 6 hours
2. Ceftriaxone 100 mg/kg/day intravenously divided every 12 hours (correct answer)
3. Cefotaxime 200 mg/kg/day intravenously divided every 6 hours
4. Vancomycin 60 mg/kg/day intravenously divided every 6 hours

Explanation: This question tests knowledge of ceftriaxone contraindications in neonates with hyperbilirubinemia. The 6-week-old infant has elevated bilirubin (10 mg/dL) and suspected bacterial meningitis requiring empiric antibiotics. Ceftriaxone (choice B) is contraindicated in neonates with hyperbilirubinemia because it displaces bilirubin from albumin binding sites, potentially causing kernicterus (bilirubin encephalopathy). Ampicillin (choice A) plus gentamicin or cefotaxime (choice C) are the preferred empiric regimens for neonatal meningitis and don't carry this risk. Vancomycin (choice D) may be added for suspected resistant organisms but doesn't affect bilirubin. The clinical principle is that ceftriaxone should be avoided in neonates less than 28 days old or any neonate with hyperbilirubinemia, making cefotaxime the preferred third-generation cephalosporin for neonatal infections when needed.

Question 20

1. Acetaminophen 650 mg by mouth every 6 hours as needed (maximum 3,000 mg/day)
2. Naproxen 500 mg by mouth twice daily with food (correct answer)
3. Cyclobenzaprine 5 mg by mouth at bedtime as needed
4. Lidocaine 4% patch: apply to affected area for up to 12 hours per day

Explanation: This question tests the recognition of cross-reactivity between NSAIDs in patients with aspirin-exacerbated respiratory disease (AERD). The patient has documented AERD with aspirin-induced bronchospasm and ibuprofen-induced wheezing, indicating sensitivity to COX-1 inhibiting NSAIDs. Naproxen (choice B) is contraindicated because it shares the same COX-1 inhibition mechanism as aspirin and ibuprofen, carrying a high risk of triggering bronchospasm in this patient. Acetaminophen (choice A) is the safest analgesic option as it has minimal COX inhibition and is well-tolerated in AERD patients. Cyclobenzaprine (choice C) is a muscle relaxant without NSAID properties, and lidocaine patches (choice D) provide local analgesia without systemic NSAID exposure. The clinical pearl is that patients with AERD should avoid all non-selective NSAIDs, and acetaminophen remains the first-line oral analgesic for these patients.