A 55-year-old woman treated with high-dose metronidazole for six weeks for anaerobic osteomyelitis develops progressive numbness and tingling in both feet. The most likely diagnosis is:

• A Metronidazole-induced peripheral neuropathy ✓
• B Guillain-Barre syndrome triggered by infection
• C Diabetic distal symmetrical polyneuropathy
• D Vitamin B12 deficiency secondary to malabsorption

Explanation

Prolonged or repeated courses of metronidazole cause a dose-related, usually reversible sensory peripheral neuropathy, and rarely CNS toxicity with cerebellar ataxia and encephalopathy. The temporal link with six weeks of continuous high-dose therapy makes the drug the clear culprit. Treatment should be stopped once neuropathy appears. Diabetes and B12 deficiency are plausible distractors but there is no supporting history, and Guillain-Barre is characteristically motor and ascending.

Reference: KD Tripathi Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.