Free practice quiz
NAPLEX Prep Course (NAPLEX): free quiz
10 questions from the program. See your score right away, then unlock the explanation of every answer.
- Question 1 of 10
A pharmacist is verifying medications for Ms. L., age 84 years, weight 58 kg, SCr 1.6 mg/dL. Her profile includes apixaban 5 mg PO twice daily for atrial fibrillation. A new prescription is clarithromycin 500 mg PO twice daily for 7 days. Which medication-related problem and pharmacist action should be prioritized?
Safety MRP—apixaban
C is correct: apixaban exposure rises with strong CYP3A4/P-gp inhibition; this patient also meets NVAF dose-reduction criteria, so clarify before dispensing. D is tempting as counseling, but spacing does not remove metabolic/transport inhibition. B is tempting for adherence, but rivaroxaban is also affected by strong inhibitors and requires renal review. A uses the right dose criterion but misses the interacting clarithromycin and need to contact the prescriber.
Pharmacist Action: NOTICE age/weight/SCr plus clarithromycin; SAY interaction and dose concern; MONITOR bleeding and renal function; HOLD/CLARIFY before concurrent therapy. - Question 2 of 10
A 76-year-old patient brings a new prescription for nirmatrelvir 300 mg/ritonavir 100 mg by mouth twice daily for 5 days for COVID-19. The profile lists apixaban, atorvastatin, and amlodipine; last serum creatinine is unavailable, and the patient reports “kidney problems.” As the verifying pharmacist, what is the safest next action before dispensing?
Core Patient Data for Antiviral Verification
C is correct. Nirmatrelvir exposure depends on renal function; ritonavir strongly inhibits CYP3A, affecting atorvastatin, amlodipine, and apixaban. A is tempting because holding atorvastatin is appropriate, but it misses renal dosing and apixaban risk. B is tempting as a dose adjustment, but the reduction is based on eGFR, not age or weight alone. D is tempting because molnupiravir avoids CYP3A inhibition, but substitution requires prescriber authorization. NOTICE missing eGFR and CYP3A interactions; SAY dose and interaction plan must be clarified; MONITOR renal function before dispensing and bleeding symptoms if apixaban continues; HOLD/CLARIFY until renal function and prescriber plan are documented.
- Question 3 of 10
As the verifying pharmacist, you review apixaban 5 mg by mouth twice daily for atrial fibrillation in a patient also taking carbamazepine 200 mg by mouth twice daily. The prescriber asks for the most authoritative source to confirm dosing and interaction safety before dispensing today. Which resource should you consult first?
Review Drug Information Resource Tiers
A is correct: labeling is authoritative for approved dosing and the strong CYP3A4/P-gp inducer warning; carbamazepine can lower apixaban exposure. D is tempting but anecdotal and not first-line for routine dosing safety. C is useful tertiary background but may lag labeling updates. B is strong primary evidence, but trials may not answer the exact interaction/dosing question quickly.
Pharmacist Action: NOTICE carbamazepine; SAY labeling recommends avoiding the interaction; MONITOR for thromboembolism/bleeding if therapy changes; HOLD/CLARIFY before dispensing until the prescriber addresses the interaction. - Question 4 of 10
A pharmacist is verifying an order for potassium chloride 20 mEq PO twice daily. The available oral solution is potassium chloride 10% w/v, and the molecular weight of KCl is 74.5 g/mol with valence 1. The patient also takes lisinopril 20 mg PO daily. After confirming therapy is intended, what volume should be dispensed for each potassium chloride dose?
Potassium chloride concentration conversion
Correct: D. For monovalent KCl, 1 \(mEq = 74\).5 mg; 20 \(mEq = 1490 mg\). A 10% w/v solution contains 10 g/100 mL = 100 mg/mL, so 1490 mg ÷ 100 \(mg/mL = 14\).9 mL. B is tempting but is a 10-fold decimal error. A uses 10 mEq instead of the ordered 20 mEq. A uses the 40 mEq daily dose as one dose. Lisinopril is an interaction red flag because ACE inhibitors can increase potassium; it does not change this volume calculation but requires monitoring.
Pharmacist Action: NOTICE ACE inhibitor use; SAY confirm potassium plan; MONITOR serum potassium and renal function; HOLD/CLARIFY if hyperkalemia or renal decline is present. - Question 5 of 10
A community pharmacist is verifying a prescription for insulin glargine-yfgn 100 units/mL pens: inject 28 units subcutaneously every night; dispense 15 mL. The profile also includes carvedilol 12.5 mg by mouth twice daily. The pen instructions require priming with 2 units before each injection. What day supply should the pharmacist enter for adjudication?
Review Insulin Pen Day Supply
A is correct: 15 mL × 100 \(units/mL = 1500 units\); daily use is 28-unit dose + 2-unit safety prime = 30 units, so 50 days. B is tempting from the prescribed dose alone, but pen labeling requires priming before injections. D is tempting because opened pens have an in-use discard period, but each 300-unit pen lasts 10 days at 30 units/day, within 28 days. C is an interaction trap: carvedilol can mask hypoglycemia symptoms, but it does not change adjudicated days supply.
Pharmacist Action: NOTICE priming units and beta-blocker use; SAY to prime each dose and monitor glucose; MONITOR hypoglycemia at refills; HOLD/CLARIFY if directions or quantity conflict. - Question 6 of 10An entry-level pharmacist is verifying vancomycin 1,000 mg IV every 12 hours for a fictional 62-year-old inpatient receiving piperacillin-tazobactam. SCr is stable at 0.9 mg/dL. A correctly timed trough before the fourth dose is 8 mg/L; the indication requires serious MRSA coverage. Which pharmacist recommendation best uses PK parameters for dosing?
Review Vancomycin AUC Monitoring
B is correct: vancomycin efficacy and toxicity correlate with AUC/MIC; guidelines recommend AUC 400–600 and Bayesian or two-level PK dosing. A is tempting because troughs were historically used, but forcing 15–20 mg/L raises nephrotoxicity risk. C is tempting because the fourth dose approximates steady state, but steady state does not replace AUC estimation. D is tempting as an interval adjustment, but piperacillin-tazobactam is a nephrotoxicity risk signal, not a reason to shorten the interval.
NOTICE low trough plus nephrotoxin; SAY recommend AUC-based adjustment; MONITOR SCr daily during acute therapy; HOLD/CLARIFY if renal function worsens or AUC exceeds 600.
- Question 7 of 10
A pharmacist is verifying an adult PN order: amino acids 90 g IV daily, dextrose 250 g IV daily, and 20% lipid injectable emulsion 250 mL IV daily. Ceftriaxone 2 g IV q24h is active on the MAR but is not admixed in the PN. Using 4 kcal/g protein, 3.4 kcal/g dextrose, and 2 kcal/mL for 20% lipid, which documentation and recommendation is most appropriate?
Protein: 90 × 4 = 360 kcal; dextrose: 250 × 3.4 = 850 kcal; 20% lipid: 250 × 2 = 500 kcal; \(total = 1\),710 kcal/day. A is tempting because lipids may hang separately, but IV lipid still contributes calories. B is correct and addresses ceftriaxone as a separate compatibility issue. C uses the enteral carbohydrate factor; parenteral dextrose is 3.4 kcal/g. D overcounts lipid and misapplies the ceftriaxone-calcium warning; separate administration does not change PN calories.
NOTICE macronutrient amounts and ceftriaxone; SAY total calories and separation plan; MONITOR glucose/triglycerides/electrolytes daily initially; HOLD/CLARIFY if admixture or Y-site compatibility is uncertain. - Question 8 of 10
A pharmacist is verifying a refill written as Toprol-XL 100 mg PO once daily. The technician selected metoprolol tartrate 100 mg tablets with directions to take 1 tablet PO once daily. The patient also takes fluoxetine 20 mg PO daily and has an eGFR of 35 mL/min/1.73 m2. Which product and directions should the pharmacist verify?
Release Form and Name Check
C is correct: Toprol-XL is metoprolol succinate ER for once-daily beta1 blockade. A is tempting because the daily dose matches, but tartrate is immediate-release and not interchangeable once daily. B is tempting with eGFR 35, but metoprolol does not require renal adjustment. D notes a real fluoxetine CYP2D6 interaction, but the response is monitoring or prescriber discussion, not automatic formulation conversion.
NOTICE the salt and release form. SAY the selected product does not match Toprol-XL. MONITOR heart rate and blood pressure after dispensing. HOLD/CLARIFY if formulation or dose intent is ambiguous. - Question 9 of 10
A community pharmacist is verifying amoxicillin/clavulanate 400 mg/57 mg per 5 mL oral suspension, 5 mL by mouth every 12 hours for 10 days for a child. The powder is reconstituted today. The manufacturer labeling states the dry powder is stored at or below 25°C and the reconstituted suspension must be refrigerated and discarded after 10 days. Which dispensing action best protects product integrity?
Storage Stability Fundamentals
C is correct: aqueous amoxicillin/clavulanate loses stability after reconstitution, especially the clavulanate component; FDA labeling requires refrigeration and discard after 10 days. B is tempting because USP provides default nonsterile aqueous BUDs, but product-specific manufacturer dating supersedes broad defaults. A is tempting as a conservative antibiotic rule, but it unnecessarily prevents completion of the labeled 10-day course. D is a dose-adjustment and interaction trap: pharmacists should not alter the prescribed regimen for storage, and iron/antacid separation is not the key stability issue.
Pharmacist Action: NOTICE reconstitution date; SAY refrigerate, shake, discard after 10 days; MONITOR adherence; HOLD/CLARIFY if dating exceeds labeling. - Question 10 of 10
A prescriber orders tretinoin 0.025% topical gel, apply a thin layer to the face nightly. The patient also uses benzoyl peroxide 5% wash each morning. As the dispensing pharmacist preparing a nonsterile compound from tretinoin powder, which base and technique are most appropriate?
Review Nonsterile Dosage Form Bases
D is correct: tretinoin is light and oxidation sensitive; an appropriate gel or cream base preserves the ordered strength, and insoluble powders need levigation plus geometric dilution for uniformity. A is tempting for skin contact, but occlusive ointment and twice-daily use may increase irritation and change the intended dosage form. C is tempting for tolerability, but the pharmacist should not halve the prescribed strength without authorization. B is tempting for acne synergy, but benzoyl peroxide can oxidize tretinoin; separate administration is preferred.
Notice tretinoin strength and benzoyl peroxide use. Say use tretinoin nightly and separate benzoyl peroxide. Monitor irritation initially. Hold/clarify ambiguous base, strength, or route.
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