Errors, Omissions, And Duplication - NAPLEX

1. A 48-year-old female (weight 70 kg) with depression and neuropathic pain reports dry mouth, constipation, and confusion. Medical history includes major depressive disorder and diabetic neuropathy; allergies: none. Current medications: amitriptyline 25 mg by mouth at bedtime, nortriptyline 25 mg by mouth at bedtime, sertraline 50 mg by mouth daily, metformin 500 mg by mouth twice daily. Labs: hemoglobin A1c 7.8%, serum creatinine 0.9 mg/dL. What is the most significant error in this patient's medication regimen?
   Answer: Unnecessary duplication of tricyclic antidepressants; discontinue one TCA and reassess adverse effects and efficacy This question tests the identification of therapeutic duplication in a patient's medication regimen, particularly with drugs sharing similar mechanisms and side effect profiles. The key patient-specific factor is the concurrent use of two tricyclic antidepressants (TCAs), amitriptyline and nortriptyline, which can amplify anticholinergic adverse effects such as dry mouth, constipation, and confusion in a patient with depression and diabetic neuropathy. Choice A is the best option because discontinuing one TCA addresses the unnecessary duplication, potentially alleviating the reported side effects while maintaining therapeutic efficacy for depression and neuropathy. Choice B is incorrect as sertraline (an SSRI antidepressant) does not duplicate the antidiabetic effects of metformin, and stopping it could worsen depression without justification. Choice C is suboptimal because increasing metformin to 2000 mg three times daily exceeds the maximum recommended dose of 2550 mg daily and metformin is not primarily indicated for neuropathy management; choice D is inappropriate as adding diphenhydramine, another anticholinergic agent, would likely exacerbate the patient's dry mouth and confusion. A key clinical pearl is to routinely screen medication lists for duplications within the same drug class to minimize cumulative toxicity. This decision framework emphasizes prioritizing the resolution of adverse effects by eliminating redundancies before adding new therapies.
2. A 29-year-old woman (weight 68 kg) is starting isotretinoin for severe acne through a dermatology clinic. Medical history includes acne vulgaris; no liver disease. Current medications: isotretinoin 30 mg by mouth twice daily, doxycycline 100 mg by mouth twice daily (leftover from prior acne treatment), and a combined oral contraceptive pill (ethinyl estradiol/levonorgestrel) 1 tablet by mouth daily. Pertinent labs: alanine aminotransferase 32 units/L (7–56), triglycerides 210 mg/dL (<150), serum creatinine 0.7 mg/dL (0.6–1.3). Allergies: none. What is the most significant error in this patient's medication regimen?
   Answer: Stop doxycycline due to increased risk of intracranial hypertension when used with isotretinoin This question tests knowledge of drug interactions causing intracranial hypertension. Concurrent use of isotretinoin and tetracycline antibiotics (including doxycycline) is contraindicated due to increased risk of pseudotumor cerebri (intracranial hypertension). Both medications independently can cause this serious adverse effect, and combination use significantly increases the risk. Option A incorrectly suggests the combination is beneficial. Option C addresses a non-existent indication. Option D is unnecessary as the oral contraceptive is appropriately required with isotretinoin for pregnancy prevention. The clinical pearl is that isotretinoin must never be combined with tetracycline antibiotics due to additive risk of intracranial hypertension; alternative acne antibiotics should be discontinued before starting isotretinoin.
3. A 58-year-old man (weight 92 kg) presents for medication therapy management after an emergency department visit for dizziness. Medical history includes hypertension, type 2 diabetes mellitus, and hyperlipidemia. Current medications: lisinopril 20 mg by mouth daily, amlodipine 10 mg by mouth daily, atorvastatin 40 mg by mouth nightly, metformin 1000 mg by mouth twice daily, and sitagliptin 100 mg by mouth daily. Pertinent labs: serum creatinine 2.2 mg/dL (0.6–1.3), estimated creatinine clearance 28 mL/min, alanine aminotransferase 22 units/L (7–56), hemoglobin A1c 7.4%. Allergies: no known drug allergies. Which error in dosing needs correction?
   Answer: Reduce sitagliptin to 25 mg by mouth daily due to creatinine clearance 28 mL/min This question tests the ability to identify inappropriate dosing in chronic kidney disease. The patient has severe renal impairment with a creatinine clearance of 28 mL/min, requiring dose adjustment for renally eliminated medications. Sitagliptin requires dose reduction to 25 mg daily when CrCl is <30 mL/min to prevent drug accumulation and potential hypoglycemia. Metformin is contraindicated when eGFR <30 mL/min due to lactic acidosis risk, making option C incorrect. Atorvastatin does not require dose adjustment for renal impairment, making option D incorrect. The clinical pearl is to always calculate creatinine clearance and adjust doses of renally eliminated drugs accordingly, particularly DPP-4 inhibitors which accumulate in kidney disease.
4. A 50-year-old male (weight 102 kg) with gastroesophageal reflux disease reports persistent symptoms despite therapy. Medical history: GERD; allergies: none. Current medications: omeprazole 20 mg by mouth daily, pantoprazole 40 mg by mouth daily, calcium carbonate chewable tablets as needed. Labs: magnesium 1.6 mg/dL (low). What is the most significant error in this patient's medication regimen?
   Answer: Unnecessary duplication of proton pump inhibitors; use a single PPI at an appropriate dose and evaluate ongoing need This question tests recognition of therapeutic duplication in acid-suppressive therapy for GERD. The key patient-specific factor is concurrent omeprazole and pantoprazole, both PPIs, leading to hypomagnesemia and potential overuse without improved control. Using a single PPI and evaluating need is the best choice to reduce risks and costs. Stopping calcium carbonate ignores its antacid role, adding ranitidine adds redundancy, and switching to esomeprazole maintains duplication. These distractors perpetuate overlap or introduce unnecessary agents. A clinical pearl is that dual PPI therapy offers no benefit over single and increases adverse effects like hypomagnesemia or infections. In GERD management, de-escalate to the lowest effective dose or H2RA if possible, assessing symptoms periodically.
5. A 64-year-old male (weight 78 kg) with chronic atrial fibrillation presents for anticoagulation follow-up. Medical history includes atrial fibrillation and hypertension; allergies: none. Current medications: warfarin 5 mg by mouth daily, amiodarone 200 mg by mouth daily, hydrochlorothiazide 25 mg by mouth daily. Labs: international normalized ratio (INR) 5.2 (high; goal 2–3), aspartate aminotransferase 26 U/L, serum creatinine 0.9 mg/dL. What is the most significant error in this patient's medication regimen?
   Answer: Warfarin dose is too high for a patient taking amiodarone; hold/adjust warfarin and manage supratherapeutic INR This question tests recognition of drug interactions affecting anticoagulation, specifically amiodarone's potentiation of warfarin. The key patient-specific factor is the supratherapeutic INR of 5.2, indicating increased bleeding risk due to the interaction. Holding or adjusting warfarin while managing the elevated INR is the best choice to prevent hemorrhage. Stopping hydrochlorothiazide is incorrect as it does not significantly affect warfarin, increasing amiodarone would worsen the interaction, and switching to aspirin ignores the atrial fibrillation indication for anticoagulation. These distractors either fail to address the interaction or inappropriately alter therapy. A clinical pearl is that amiodarone inhibits warfarin metabolism, often requiring a 30-50% dose reduction in warfarin. Use a framework of monitoring INR closely when starting interacting drugs and adjusting doses empirically based on interaction severity.
6. A 65-year-old male (weight 76 kg) is prescribed trimethoprim-sulfamethoxazole for cellulitis. Medical history includes atrial fibrillation on warfarin; allergies: none. Current medications: warfarin 4 mg by mouth daily, metoprolol tartrate 50 mg by mouth twice daily. Baseline INR last week was 2.4 (goal 2–3); today INR is not yet checked. What monitoring is needed for this patient?
   Answer: Check INR within 3–5 days after starting trimethoprim-sulfamethoxazole and adjust warfarin as needed This question tests monitoring for drug interactions in anticoagulation therapy. The key patient-specific factor is the addition of trimethoprim-sulfamethoxazole, which potentiates warfarin's effect by inhibiting metabolism and vitamin K-producing bacteria. Checking INR within 3-5 days and adjusting warfarin is the best choice to prevent bleeding complications. Monitoring A1c or troponin is irrelevant to this interaction, and assuming no significance ignores the well-documented risk. These distractors fail to address the potential for supratherapeutic INR. A clinical pearl is that sulfonamides like TMP-SMX can increase INR by 20-50%, necessitating proactive monitoring. Use a framework of anticipating INR changes with interacting antibiotics and scheduling checks based on interaction onset, typically 3-7 days.
7. A 45-year-old female (weight 85 kg) with type 2 diabetes requests refills and reports she has been taking two "metformin" products. Medical history: type 2 diabetes, obesity; allergies: none. Current medications: metformin immediate-release 1000 mg by mouth twice daily, metformin extended-release 1000 mg by mouth nightly, semaglutide 1 mg subcutaneously weekly. Labs: hemoglobin A1c 6.9%, serum creatinine 0.8 mg/dL. What adjustment should be made to avoid duplication?
   Answer: Discontinue metformin immediate-release and continue metformin extended-release 1000 mg nightly This question tests the identification of therapeutic duplication in diabetes management with multiple metformin formulations. The key patient-specific factor is the concurrent use of immediate-release and extended-release metformin, leading to potential overdose and gastrointestinal side effects despite controlled A1c. Discontinuing immediate-release and continuing extended-release avoids duplication while maintaining effective dosing. Continuing both or adding pioglitazone increases side effect risk, switching to insulin ignores the duplication, and stopping semaglutide is unnecessary. These options either perpetuate the error or introduce unneeded changes. A clinical pearl is to consolidate to a single metformin formulation, preferring extended-release for better tolerability in patients with GI issues. In regimens, always screen for same-drug duplications by verifying formulations and total daily doses.
8. A 40-year-old male (weight 88 kg) with epilepsy requests an early refill and reports excessive sleepiness. Medical history includes seizure disorder; allergies: none. Current medications: carbamazepine immediate-release 200 mg by mouth three times daily, carbamazepine extended-release 200 mg by mouth twice daily. Labs: sodium 130 mEq/L (low), serum creatinine 0.9 mg/dL, alanine aminotransferase 22 U/L. What adjustment should be made to avoid duplication?
   Answer: Discontinue one carbamazepine formulation and clarify intended regimen with prescriber to avoid duplicate therapy This question tests recognition of therapeutic duplication in antiepileptic therapy with multiple carbamazepine formulations. The key patient-specific factor is the combined immediate- and extended-release carbamazepine, leading to excessive dosing and side effects like hyponatremia and somnolence. Discontinuing one formulation and clarifying with the prescriber avoids duplication and toxicity. Adding levetiracetam or switching to gabapentin perpetuates or ignores the overlap, and increasing immediate-release worsens side effects. These options increase seizure risk or adverse events unnecessarily. A clinical pearl is to use a single formulation of carbamazepine, monitoring levels (4-12 mcg/mL) to guide dosing. In epilepsy regimens, screen for same-drug duplications by totaling daily doses and adjusting for formulation differences.
9. A 74-year-old male (weight 80 kg) with type 2 diabetes and chronic kidney disease comes for MTM. Medical history includes type 2 diabetes, CKD stage 3b, and hypertension; allergies: none. Current medications: metformin 1000 mg by mouth twice daily, insulin glargine 20 units subcutaneously nightly, amlodipine 10 mg by mouth daily. Labs: serum creatinine 2.0 mg/dL; estimated creatinine clearance 28 mL/min; hemoglobin A1c 7.2%. Which error in dosing needs correction?
   Answer: Metformin dose/use is inappropriate at creatinine clearance 28 mL/min; contact prescriber to discontinue or adjust per renal function This question tests renal dosing considerations for metformin in diabetes with CKD. The key patient-specific factor is the CrCl of 28 mL/min, where metformin is contraindicated due to lactic acidosis risk. Contacting the prescriber to discontinue or adjust is the best choice to ensure safety while maintaining glycemic control. Doubling insulin glargine is arbitrary, stopping amlodipine is irrelevant, and adding glyburide risks hypoglycemia in CKD. These alternatives fail to address the contraindication or introduce new risks. A clinical pearl is that metformin is contraindicated if CrCl <30 mL/min; calculate CrCl using Cockcroft-Gault for accuracy. For renal adjustments, use: CrCl = [(140-74) x 80] / (72 x 2.0) = 28 mL/min, confirming the need for discontinuation.
10. A 56-year-old female (weight 72 kg) is newly diagnosed with asthma and receives a prescription for an inhaler. Medical history includes persistent asthma symptoms several days per week; allergies: none. Current medications: albuterol metered-dose inhaler 2 puffs every 4–6 hours as needed. New prescription: fluticasone/salmeterol 250/50 mcg Diskus—inhale 1 puff by mouth every 4–6 hours as needed for shortness of breath. Labs: not applicable. What is the most significant error in this patient's medication regimen?
    Answer: Incorrect directions; fluticasone/salmeterol should be used as scheduled maintenance (e.g., 1 puff twice daily), not as needed This question tests appropriate use and directions for asthma controller medications. The key patient-specific factor is the prescription of fluticasone/salmeterol as 'as needed,' which is incorrect for a maintenance combination inhaler. Correcting to scheduled use (e.g., 1 puff BID) is the best choice to provide consistent control for persistent asthma. Stopping albuterol removes necessary rescue, increasing the dose promotes overuse, and inhaled corticosteroids are essential in asthma. These distractors lead to poor control or misuse. A clinical pearl is that ICS/LABA combinations like fluticasone/salmeterol are for daily maintenance, not PRN, to reduce exacerbations. In asthma management, distinguish controllers (scheduled) from relievers (PRN) using GINA guidelines for stepwise therapy.
11. A 58-year-old male (weight 92 kg) presents for medication therapy management after a myocardial infarction 3 months ago; he reports no medication side effects and asks if his regimen is complete. Medical history includes coronary artery disease with prior MI, hypertension, hyperlipidemia, and type 2 diabetes; allergies: none. Current medications: lisinopril 20 mg by mouth daily, metoprolol succinate extended-release 100 mg by mouth daily, atorvastatin 80 mg by mouth nightly, metformin 1000 mg by mouth twice daily. Labs: serum creatinine 1.0 mg/dL, alanine aminotransferase 28 U/L, hemoglobin A1c 7.4%. Which medication is missing from this patient's therapy?
    Answer: Aspirin 81 mg by mouth daily This question tests the application of guideline-directed medical therapy for secondary prevention after myocardial infarction. The key patient-specific factor is the history of myocardial infarction with no reported bleeding risks or contraindications to antiplatelet therapy. Aspirin 81 mg daily is the best choice as it is a cornerstone of secondary prevention to reduce the risk of recurrent cardiovascular events in post-MI patients. Clopidogrel is not routinely added without aspirin unless contraindicated, warfarin is inappropriate without indications like atrial fibrillation, and furosemide is not indicated without heart failure symptoms. Adding clopidogrel or warfarin could increase bleeding risk unnecessarily, while furosemide might cause electrolyte imbalances without edema or congestion. A clinical pearl is that all post-MI patients should receive indefinite low-dose aspirin unless contraindicated, often combined with other agents based on individual risk. When optimizing regimens, always assess for omissions in evidence-based therapies like antiplatelets, statins, beta-blockers, and ACE inhibitors.
12. A 61-year-old male (weight 84 kg) with benign prostatic hyperplasia reports lightheadedness and one fall. Medical history includes BPH and hypertension; allergies: none. Current medications: tamsulosin 0.4 mg by mouth daily, doxazosin 4 mg by mouth at bedtime, lisinopril 20 mg by mouth daily. Labs: blood pressure 98/60 mmHg. What adjustment should be made to avoid duplication?
    Answer: Discontinue one alpha-1 blocker (tamsulosin or doxazosin) and reassess symptoms and blood pressure This question tests identification of therapeutic duplication in alpha-1 blocker use for BPH and hypertension. The key patient-specific factor is concurrent tamsulosin and doxazosin, both alpha-1 blockers, causing hypotension and falls as seen with low BP and dizziness. Discontinuing one and reassessing is the best choice to minimize orthostatic risks while addressing symptoms. Adding finasteride maintains duplication, increasing doxazosin worsens hypotension, and stopping lisinopril removes needed BP control. These options exacerbate adverse effects or inadequately manage conditions. A clinical pearl is to avoid combining non-selective (doxazosin) and selective (tamsulosin) alpha-1 blockers due to additive hypotensive effects. In BPH regimens, prefer monotherapy and monitor for orthostasis, especially in hypertensives.
13. A 60-year-old male (weight 83 kg) is started on spironolactone for heart failure. Medical history includes HFrEF and hypertension; allergies: none. Current medications: spironolactone 25 mg by mouth daily (new), lisinopril 20 mg by mouth daily, carvedilol 12.5 mg by mouth twice daily, furosemide 20 mg by mouth daily. Baseline labs today: potassium 4.9 mEq/L, serum creatinine 1.3 mg/dL. What monitoring is needed for this patient?
    Answer: Check potassium and serum creatinine within 3–7 days of initiation and again at 1 month, then periodically This question assesses appropriate laboratory monitoring for aldosterone antagonists like spironolactone in patients with heart failure with reduced ejection fraction (HFrEF). The key patient-specific factors include the initiation of spironolactone at 25 mg daily alongside an ACE inhibitor (lisinopril), with baseline potassium at 4.9 mEq/L (upper normal limit) and serum creatinine at 1.3 mg/dL indicating potential renal impairment risk. Choice A is the best monitoring plan as it checks potassium and serum creatinine within 3–7 days, at 1 month, and periodically thereafter to detect hyperkalemia or worsening renal function early, which are common risks with this combination. Choice B is incorrect because the patient is not on warfarin, so INR monitoring for a spironolactone-warfarin interaction is irrelevant; choice C is suboptimal as spironolactone does not typically cause significant hyperglycemia requiring A1c checks in 2 weeks. Choice D is inappropriate because spironolactone requires routine monitoring due to its potassium-sparing effects, especially in HFrEF patients on renin-angiotensin system inhibitors. A transferable clinical pearl is that in heart failure management, aldosterone antagonists necessitate close electrolyte and renal function surveillance to prevent life-threatening complications like hyperkalemia. This framework involves tailoring monitoring frequency based on baseline labs and concurrent medications that affect potassium or renal clearance.
14. A 66-year-old female (weight 62 kg) with hypothyroidism reports palpitations and weight loss. Medical history includes hypothyroidism; allergies: none. Current medications: levothyroxine 75 mcg by mouth daily, levothyroxine 50 mcg by mouth daily (from an older bottle she continued), calcium carbonate 500 mg by mouth twice daily. Labs: thyroid-stimulating hormone (TSH) 0.05 mIU/L (low). What adjustment should be made to avoid duplication?
    Answer: Stop one levothyroxine product and confirm the intended single daily dose with the prescriber; counsel on separating from calcium This question tests identification of therapeutic duplication in thyroid hormone replacement. The key patient-specific factor is the use of two levothyroxine doses concurrently, leading to overdose symptoms and suppressed TSH, compounded by calcium interference. Stopping one product, confirming the dose, and counseling on separation is the best choice to normalize thyroid function. Continuing both or adding propranolol risks thyrotoxicosis, stopping calcium ignores its need, and switching to liothyronine is unnecessary. These options perpetuate overdose or introduce unneeded drugs. A clinical pearl is to administer levothyroxine on an empty stomach, separating from calcium by 4 hours to optimize absorption. In hypothyroidism management, verify total daily dose and monitor TSH every 6-8 weeks after changes.
15. A 63-year-old male (weight 79 kg) with a history of ischemic stroke is seen for secondary prevention review. Medical history includes prior ischemic stroke, hypertension, and hyperlipidemia; allergies: none. Current medications: atorvastatin 40 mg by mouth nightly, amlodipine 5 mg by mouth daily. Labs: serum creatinine 1.0 mg/dL, alanine aminotransferase 30 U/L, blood pressure 132/78 mmHg. Which medication is missing from this patient's therapy?
    Answer: Aspirin 81 mg by mouth daily (or another appropriate antiplatelet) for secondary stroke prevention This question tests secondary prevention strategies after ischemic stroke. The key patient-specific factor is the history of ischemic stroke without atrial fibrillation, necessitating antiplatelet therapy for recurrence prevention. Adding aspirin 81 mg daily is the best choice as it reduces stroke risk by about 20% in non-cardioembolic cases. Rivaroxaban is not indicated without AF, clonidine lacks preventive evidence, and prednisone can increase vascular risks. These alternatives are inappropriate or harmful for secondary prevention. A clinical pearl is that aspirin monotherapy is first-line for secondary stroke prevention in non-AF patients, with dual therapy considered for high-risk cases. Use a decision framework of assessing stroke etiology (e.g., TOAST classification) to select antiplatelet vs. anticoagulant therapy.
16. A 73-year-old female (weight 66 kg) is on chronic opioid therapy for osteoarthritis and requests advice for constipation. Medical history includes osteoarthritis, chronic pain; allergies: none. Current medications: oxycodone 10 mg by mouth three times daily, acetaminophen 650 mg by mouth every 6 hours as needed, omeprazole 20 mg by mouth daily. Labs: serum creatinine 1.0 mg/dL, alanine aminotransferase 24 U/L. Which medication is missing from this patient's therapy?
    Answer: A stimulant or osmotic laxative regimen (e.g., senna or polyethylene glycol) for opioid-induced constipation prophylaxis This question tests prophylaxis for opioid-induced constipation in chronic pain management. The key patient-specific factor is chronic opioid use without a laxative, increasing constipation risk in an elderly patient. Adding a stimulant or osmotic laxative like senna or polyethylene glycol is the best choice for effective prophylaxis. Docusate alone is often insufficient, loperamide would worsen constipation, and diphenhydramine has no role in motility. These distractors are ineffective or counterproductive for OIC. A clinical pearl is that all patients on scheduled opioids should receive prophylactic laxatives, preferring stimulants over stool softeners for OIC. Use a decision framework of assessing bowel regimen in opioid users and escalating to osmotics if stimulants fail.
17. A 26-year-old female (weight 58 kg) is 10 weeks pregnant and asks about a refill. Medical history includes chronic hypertension; allergies: none. Current medications: lisinopril 20 mg by mouth daily, prenatal vitamin 1 tablet by mouth daily. Labs: serum creatinine 0.6 mg/dL, potassium 4.1 mEq/L. What should the pharmacist do to resolve the contraindication?
    Answer: Recommend stopping lisinopril and contacting the prescriber promptly to switch to a pregnancy-compatible antihypertensive This question tests recognition of teratogenic contraindications in pregnancy. The key patient-specific factor is the 10-week pregnancy, making lisinopril contraindicated due to fetal renal and cardiovascular risks. Recommending to stop lisinopril and contact the prescriber for a safer alternative like labetalol is the best choice for maternal-fetal safety. Continuing or reducing lisinopril exposes the fetus to harm, and adding potassium is irrelevant. These distractors prioritize BP over fetal risks inappropriately. A clinical pearl is that ACE inhibitors are pregnancy category D/X, requiring immediate discontinuation upon pregnancy confirmation. Use a framework of reviewing all medications for teratogenicity in reproductive-age women and switching to pregnancy-safe options promptly.
18. A 45-year-old woman (weight 63 kg) presents to the pharmacy with a new prescription for pain after a dental procedure. Medical history includes asthma and nasal polyps; she reports a prior episode of hives and wheezing after taking ibuprofen. Current medications: albuterol metered-dose inhaler 2 puffs every 4–6 hours as needed, fluticasone/salmeterol 100 mcg/50 mcg inhaled twice daily, and cetirizine 10 mg by mouth daily. Pertinent labs: serum creatinine 0.8 mg/dL (0.6–1.3). Allergies: ibuprofen (hives, wheezing). New prescription: naproxen 500 mg by mouth twice daily as needed for pain. What should the pharmacist do to resolve the contraindication?
    Answer: Recommend acetaminophen 650 mg by mouth every 6 hours as needed and contact the prescriber to change therapy This question tests recognition of NSAID cross-reactivity in aspirin-exacerbated respiratory disease (AERD). The patient has the classic triad of asthma, nasal polyps, and NSAID sensitivity, indicating AERD (Samter's triad). Naproxen is contraindicated due to cross-reactivity with all nonselective NSAIDs in patients with ibuprofen-induced bronchospasm. Option B correctly recommends acetaminophen as a safe alternative and contacting the prescriber. Option A is incorrect because all nonselective NSAIDs cross-react in AERD. Option C does not address the contraindication. Option D is dangerous as pre-treatment with albuterol will not prevent severe bronchospasm. The clinical pearl is that patients with AERD must avoid all nonselective NSAIDs; acetaminophen and selective COX-2 inhibitors (at low doses) are safer alternatives.
19. A 66-year-old woman (weight 74 kg) is seen in clinic for follow-up after a transient ischemic attack 2 weeks ago; she reports no bleeding. Medical history includes hypertension and hyperlipidemia. Current medications: atorvastatin 40 mg by mouth nightly, lisinopril 10 mg by mouth daily, hydrochlorothiazide 25 mg by mouth daily, and omeprazole 20 mg by mouth daily. Pertinent labs: serum creatinine 0.9 mg/dL (0.6–1.3), alanine aminotransferase 18 units/L (7–56), blood pressure 132/78 mmHg. Allergies: none. Which medication is missing from this patient's therapy?
    Answer: Aspirin 81 mg by mouth daily for secondary stroke prevention This question tests knowledge of secondary stroke prevention after transient ischemic attack (TIA). The patient experienced a TIA 2 weeks ago and requires antiplatelet therapy for secondary prevention. Aspirin 81 mg daily is the first-line antiplatelet agent for secondary stroke prevention and is notably absent from her regimen. Clopidogrel 75 mg daily (option A) is an alternative first-line option but not superior to aspirin. Warfarin (option C) is not indicated for TIA without atrial fibrillation or other cardioembolic source. Dipyridamole/aspirin (option D) is an alternative but not preferred over aspirin monotherapy due to increased side effects. The clinical pearl is that all patients with TIA or ischemic stroke require antiplatelet therapy unless anticoagulation is indicated for another reason.
20. A 52-year-old man (weight 95 kg) with chronic low back pain requests an early refill and reports taking extra doses for breakthrough pain. Medical history includes chronic pain and depression. Current medications: oxycodone immediate-release 5 mg by mouth every 6 hours as needed, oxycodone extended-release 10 mg by mouth every 12 hours, sertraline 100 mg by mouth daily, and docusate 100 mg by mouth twice daily. Pertinent labs: serum creatinine 0.9 mg/dL (0.6–1.3), alanine aminotransferase 24 units/L (7–56). Allergies: none. What is the most significant error in this patient's medication regimen?
    Answer: Omission of a bowel regimen escalation; add a stimulant laxative (e.g., senna) due to chronic opioid use This question tests recognition of inadequate constipation prophylaxis in chronic opioid therapy. The patient is on scheduled extended-release oxycodone plus immediate-release for breakthrough pain but only has docusate (a stool softener) for constipation prevention. Chronic opioid use requires a stimulant laxative (like senna or bisacodyl) in addition to a stool softener for adequate bowel regimen. Option A is incorrect as combining long-acting and short-acting opioids is appropriate pain management. Option C is false as sertraline can be used with opioids. Option D suggests an inappropriate formulation change. The clinical pearl is that all patients on chronic opioids require both a stool softener AND a stimulant laxative; docusate alone is insufficient for opioid-induced constipation prevention.

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