Metronidazole-induced neurotoxicity

A 50 year old male with history of prolonged intake of metronidazole for treatment of liver abscess developed acute ataxia, disorientation, distal symmetrical sensory and proximal motor neuropathy. Patients being treated with metronidazole particularly those on high doses for prolonged period should be monitored for neurotoxicity. extremes of vision. He exhibited past-pointing on finger-nose test. He was severely ataxic and was unable to walk unassisted without falling. Routine laboratory results including CSF examination were unremarkable. CT scan (head) revealed hypodense areas in the cerebellum (Fig. 1). Within 3 to 4 days of stopping metronidazole patient’s condition improved remarkably with normal mentation, his speech became coherent, cerebellar signs were much improved, and he could walk unassisted although he remained unsteady. He then disclosed that after about three weeks of initial discharge, he had developed progressive numbness, tingling and pain in both lower limbs. Symptoms started distally and slowly progressed proximally and involved both hands as well. After 3 to 4 weeks he also experienced difficulty in standing from a squatting position followed by difficulty in *Senior Resident; **Reader; ***Professor;****DNB Student, Department of Medicine, University College of Medical Sciences and GTB Hospital, Delhi 110 095. Received : 2.8.2001; Accepted : 29.4.2003 INTRODUCTION Metronidazole is a 5-nitroimidazole and has potent activity against anaerobic bacteria, several protozoa including Entamoeba, Giardia, Trichomonas and B. coli, H. pylori and Guinea worm. It is generally well tolerated and common side effects include nausea, dizziness, ataxia, seizures, encephalopathy and neuropathy. We are presenting a case report of a patient who developed a combination of neurotoxic manifestations following prolonged intake of metronidazole.