B48-13 Severe Serotonin Syndrome With Acute Respiratory Failure Following Ayahuasca and Dextromethorphan Use: A Case Report
American Journal of Respiratory and Critical Care Medicine May 1, 2026 S Pack, T Ellett, J Pham et al.
A 46-year-old man developed life-threatening serotonin syndrome after consuming ayahuasca at a retreat and later taking dextromethorphan and diphenhydramine. He presented with agitation, hyperthermia, tachycardia, and respiratory failure requiring intubation and intensive care. Treatment with cyproheptadine and midazolam led to full recovery within three days. The case highlights the dangerous interaction between ayahuasca's monoamine oxidase inhibitors and over-the-counter serotonergic medications, which can synergistically cause severe toxicity.