Haloperidol, a Novel Treatment for Cannabinoid Hyperemesis Syndrome.

Cannabinoid hyperemesis syndrome (CHS) is typically unresponsive to conventional pharmacologic antiemetics, and patients often require excessive laboratory and radiographic testing and hospital admission. We report 4 cases of CHS that failed standard emergency department therapy but improved significantly after treatment with haloperidol. Although the exact mechanism for CHS remains unclear, dysregulation at cannabinoid type 1 seems to play a role. Recent animal data demonstrate complex interactions between dopamine and cannabinoid type 1 signaling, a potential mechanism for haloperidol success in patients with CHS. Our success with haloperidol in these 4 patients warrants further investigation of haloperidol as an emergency department treatment for CHS.