PEBC Treatment Planning 2 — Questions and Answers
Question 1: A 68-year-old patient with type 2 diabetes and CKD stage 3 (eGFR 35 mL/min/1.73m²) is poorly controlled on metformin 1000 mg BID. Which adjustment is most appropriate?
- Increase metformin to 2000 mg BID
- Discontinue metformin and initiate insulin (Correct answer)
- Reduce metformin to 500 mg BID and monitor renal function
- Add sitagliptin without changing metformin
Correct answer: Discontinue metformin and initiate insulin
Metformin is contraindicated when eGFR falls below 30 and should be used with caution below 45; at eGFR 35 with poor control, transitioning to insulin is the safest option.
Question 2: A patient on warfarin for atrial fibrillation requires short-term analgesia. Which agent poses the LEAST risk of significant drug interaction?
- Ibuprofen 400 mg TID
- Naproxen 500 mg BID
- Acetaminophen 500 mg Q6H PRN (Correct answer)
- Celecoxib 200 mg daily
Correct answer: Acetaminophen 500 mg Q6H PRN
Acetaminophen at low-to-moderate doses is the preferred analgesic in warfarin patients as NSAIDs increase bleeding risk through antiplatelet effects and GI irritation.
Question 3: Which pharmacokinetic parameter is most relevant when designing a dosing regimen to maintain drug concentrations above the MIC for a time-dependent antibiotic like amoxicillin?
- Peak concentration (Cmax/MIC ratio)
- Area under the curve (AUC/MIC ratio)
- Time above MIC (%T>MIC) (Correct answer)
- Volume of distribution
Correct answer: Time above MIC (%T>MIC)
Beta-lactams like amoxicillin exhibit time-dependent killing, so the pharmacodynamic target is the percentage of the dosing interval that free drug concentrations exceed the MIC.
Question 4: A 55-year-old woman with osteoporosis and GERD is prescribed alendronate. What counselling point is MOST critical for effective treatment?
- Take with a full glass of milk to enhance calcium absorption
- Take immediately after breakfast to reduce GI side effects
- Take on an empty stomach with plain water and remain upright for 30 minutes (Correct answer)
- Take at bedtime to improve bone metabolism during sleep
Correct answer: Take on an empty stomach with plain water and remain upright for 30 minutes
Bisphosphonates must be taken on an empty stomach with 8 oz of plain water, and the patient must remain upright for at least 30 minutes to prevent esophageal irritation.
Question 5: A patient with heart failure (EF 35%) and hypertension is already on an ACE inhibitor and beta-blocker. Which additional agent has the strongest evidence for reducing mortality in this population?
- Amlodipine 5 mg daily
- Spironolactone 25 mg daily (Correct answer)
- Hydralazine 25 mg TID
- Digoxin 0.125 mg daily
Correct answer: Spironolactone 25 mg daily
Aldosterone antagonists like spironolactone have demonstrated mortality reduction in HFrEF patients already on ACE inhibitors and beta-blockers in landmark trials such as RALES.
Question 6: A pharmacist reviews a prescription for ciprofloxacin 500 mg BID for a patient also taking sucralfate. What is the most appropriate action?
- Dispense as written; there is no significant interaction
- Recommend taking ciprofloxacin 2 hours before or 6 hours after sucralfate (Correct answer)
- Switch ciprofloxacin to amoxicillin-clavulanate to avoid the interaction
- Discontinue sucralfate immediately
Correct answer: Recommend taking ciprofloxacin 2 hours before or 6 hours after sucralfate
Sucralfate chelates fluoroquinolones and significantly reduces their absorption; separating administration by at least 2 hours before or 6 hours after sucralfate resolves this interaction.
Question 7: Which monitoring parameter is MOST important to assess within the first 1–2 weeks of initiating an ACE inhibitor in a patient with hypertension and mild CKD?
- Serum sodium and chloride
- Serum potassium and creatinine (Correct answer)
- Liver function tests
- Complete blood count
Correct answer: Serum potassium and creatinine
ACE inhibitors can cause hyperkalemia and an acute rise in serum creatinine, particularly in patients with CKD, making early electrolyte and renal function monitoring essential.
PEBC Treatment Planning 2
A 68-year-old patient with type 2 diabetes and CKD stage 3 (eGFR 35 mL/min/1.73m²) is poorly controlled on metformin 1000 mg BID.
Which adjustment is most appropriate?