Metronidazole-associated mood changes: A case report

Introduction Metronidazole is an antibiotic used in the treatment of wide array of bacterial infections. Case report This case report describes a 55-year-old female patient taking treatment for sigmoid non-complicated diverticulitis who developed an unanticipated adverse drug reaction with metronidazole and ciprofloxacin. Discussion The patient had previously experienced mood changes while receiving bismuth-based therapy for Helicobacter pylori infection. During metronidazole therapy, no drugs other than ciprofloxacin were administered. The Naranjo Probability Score was calculated at 7. Therefore, the association between metronidazole and the mood changes experienced by the patient is probable. Conclusion To manage the mood changes, metronidazole was discontinued with a favorable clinical response. Although this adverse drug event is uncommon, clinicians should be vigilant about identifying mood changes that may occur with metronidazole, and promptly discontinuing the drug. Significance statement • Clinicians should monitor for mood changes during metronidazole therapy. • Prompt drug discontinuation may rapidly reverse neuropsychiatric adverse reactions.