Pharmacology · single question
Which medication requires DOSE ADJUSTMENT in patients with CHRONIC KIDNEY DISEASE?
Show answer and explanation
Correct answer: A. Cefalexin (Cephalexin)
Cefalexin (cephalexin, a first-generation cephalosporin) is primarily renally excreted and requires dose reduction in chronic kidney disease. Clindamycin is hepatically metabolized and does NOT require renal dose adjustment. Amoxicillin requires dose adjustment only in severe renal impairment (GFR <30). Tetracycline is CONTRAINDICATED in renal failure (accumulates, can worsen uremia) — not just 'adjusted.' Per most dental pharmacology references, Cefalexin is the classic 'requires dose adjustment' antibiotic in the renal context.
- A. Incorrect. Amoxicillin requires dose adjustment only in severe CKD (GFR <10-30) but not in moderate CKD — and is generally considered safer than cefalexin for renal patients.
- B. CORRECT. Cefalexin (cephalexin) is renally cleared and requires dose adjustment in CKD patients — accumulation can cause neurotoxicity.
- C. Incorrect. Clindamycin is primarily hepatically metabolized (biliary excretion) — it does NOT require dose adjustment for renal impairment.
- D. Incorrect. Tetracycline is CONTRAINDICATED (not just adjusted) in renal failure — it increases nitrogen load and worsens uremia. It is avoided entirely, not merely dose-adjusted.