Potential Dextromethorphan-Induced Serotonin Syndrome Leading to Homicide and Suicide.

Limited case reports have been published regarding serotonin syndrome due to the combined effects of supratherapeutic levels of dextromethorphan and selective serotonin reuptake inhibitor. We report a case of an adolescent with postmortem findings suggestive of a diagnosis of serotonin syndrome-induced psychosis associated with a double homicide and suicide. Postmortem toxicology of the suicide victim was remarkable for elevated serotonergic metabolites of fluoxetine and dextromethorphan in a 14-year-old male.