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DDx Episode 3

Extreme reactions to marijuana

11 minutes


John Richards, M.D.

Dr. John Richards is a Professor of Emergency Medicine at the University of California, Davis Medical Center, a Level I trauma and tertiary care center serving Central and Northern California. His research interests include the treatment of acute toxicity from drugs of abuse, specifically cocaine, amphetamine derivatives such as methamphetamine and MDMA (Ecstasy), cannabis, opioids, and alcohol. Another aspect of his research is the analysis of medical mythology and outdated treatment guidelines using an evidence-based approach.


A 37-year-old man presents to the emergency department in the middle of the night with persistent vomiting and retching. He is highly vocal and agitated. Upon questioning, he reveals that he experiences these episodes frequently and previous investigations have all been inconclusive. His skin is noted to be flushed and his father explains that he has spent most of the day taking a hot shower. At this point, Dr. John Richards realizes the key piece of information other physicians may have overlooked. “Do you smoke marijuana?” he asks.