A 74-year-old man with diabetic nephropathy (eGFR 22 mL/min/1.73 m2) on long-term glyburide is found drowsy with capillary glucose of 38 mg/dL. He requires repeated dextrose infusions over 36 hours. Which property of glyburide best explains this prolonged course?

• A It is a weak inducer of hepatic CYP enzymes
• B It antagonizes glucagon receptors in the liver
• C Its active metabolites are renally excreted and accumulate in renal failure ✓
• D It forms an insoluble depot in adipose tissue

Explanation

Glyburide (glibenclamide) produces active metabolites that are cleared by the kidney, so renal failure leads to accumulation and prolonged, recurrent hypoglycemia. It is therefore avoided in elderly patients and in CKD. Shorter-acting agents such as gliclazide or non-sulfonylurea secretagogues are preferred. Glyburide is not a CYP inducer, has no glucagon antagonist action, and its persistence reflects metabolite accumulation rather than fat depots.

Reference: Goodman and Gilman's The Pharmacological Basis of Therapeutics, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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