Psychotic mania induced by metronidazole: A rare case of antibiomania

Metronidazole, a widely used antimicrobial agent, has been associated with rare neuropsychiatric adverse effects, including antibiotic-induced mania (antibiomania). We report the case of a 46-year-old woman with a history of bipolar disorder type I, previously triggered by antidepressant treatment, who presented with an acute onset of a manic episode with psychotic features following prolonged metronidazole treatment. The patient had remained euthymic and medication-free for approximately nine years prior to this episode. Metronidazole was discontinued upon admission, and appropriate psychiatric treatment was initiated. Manic and psychotic symptoms resolved completely within three days, supporting a probable causal association. This case highlights the potential of metronidazole to induce manic episodes, particularly in individuals with a predisposition to mood disorders, and aims to discuss the possible underlying mechanisms through which metronidazole may contribute to the development of mania.