Short-course metronidazole-induced reversible acute neurotoxicity in a renal transplant recipient

Neurotoxic manifestations due to chronic metronidazole intake are well known, but neurotoxicity due to short-term use of metronidazole is very rare. We present a case of acute neurotoxicity due to short course of injectable metronidazole given in usual doses to a renal allograft recipient for persistent diarrhea. It responded to withdrawal of the offending drug. Tacrolimus trough concentration did not increase during neurotoxicity, thereby ruling out any metronidazole-tacrolimus interaction. Magnetic resonance imaging of the brain showed widespread osmotic demyelination and its recovery after drug withdrawal. This is the first reported case of a renal transplant recipient developing acute neurotoxicity due to short-term use of metronidazole, without any increase in tacrolimus trough concentrations.