Exacerbation of neuropsychiatric symptoms in an adult male with influenza A virus treated with oseltamivir

Oseltamivir (Tamiflu) package labeling has a warning for neuropsychiatric adverse events (NPAE), most commonly in children and adolescents, especially males. There are several case reports of NPAE in adults treated with oseltamivir, but few document patients with preexisting neuropsychiatric conditions without additional contributing factors. This case report describes a 22-year-old male with a history of bipolar disorder, depression, and attention-deficit/hyperactivity disorder who had been stable on his medication regimen before experiencing sudden worsening of symptoms after the initiation of oseltamivir. The case adds to previous literature by strengthening the correlation between oseltamivir and a sudden increase in neuropsychiatric symptoms. Providers should be aware that oseltamivir may exacerbate symptoms of previously stable patients. Depending on the severity of neuropsychiatric effects, discontinuation of oseltamivir and symptom treatment with pharmacotherapy may be warranted.