IntroductionMetronidazole is an antibiotic that is widely used to treat a range of bacterial and protozoan infections, especially those caused by anaerobic bacteria and parasites ( 1 ). It is potent against bacterial vaginosis, Clostridium difficile infections, and Giardia lamblia infections (2, 3). Metronidazole kills these organisms by directly interfering with nucleic acid synthesis (4). Although metronidazole is very effective, it is also associated with a number of adverse effects, which can include both gastrointestinal effects and, to a lesser extent, neurological effects. Although the drug is well tolerated, prolonged use or high doses are associated with severe therapeutic responses(5).Metronidazole-induced encephalopathy (MIE) is one of the most severe and rare issues related to metronidazole use and is reflected in a wide range of neurological manifestations including confusion, seizures, and ataxia (6). These symptoms have mainly been observed in patients treated with higher doses of metronidazole and for a longer time period, in particular in those with hepatic impairment, wherein drug excretion is impaired (7). The exact mechanism of MIE is not yet known, but it is thought to involve accumulation of neurotoxic metabolites or direct neurotoxicity of metronidazole (8). With an increasing awareness of this diagnosis, it is imperative that healthcare professionals remain vigilant in identifying patients who may experience this potentially serious side effect resulting from metronidazole therapy, particularly among those who have been on the medication long term, in order to institute timely diagnosis and management.We present a case of a 79-year-old woman who developed neurological symptoms after being treated with metronidazole to a liver abscess.
