The cannabis hyperemesis syndrome characterized by persistent nausea and vomiting, abdominal pain, and compulsive bathing associated with chronic Cannabis use: a report of eight cases in the United States.

<h4>Goals/background</h4>The cannabis hyperemesis syndrome, which is associated with chronic cannabis use, was recently reported in seven case reports and one clinical series of ten patients from Australia. We further characterize this syndrome with eight well-documented cases in the United States and report results of cannabis discontinuation and cannabis rechallenge.<h4>Study methods</h4>Patients were identified by the three investigators in gastroenterology clinic or inpatient wards at William Beaumont Hospital from January to August 2009 based on chronic cannabis use; otherwise unexplained refractory, recurrent vomiting; and compulsive bathing. Charts were retrospectively analyzed with follow-up data obtained from subsequent physician visits and patient interviews.<h4>Results</h4>The eight patients on average were 32.4 ± 4.1 years old. Five were male. The mean interval between the onset of cannabis use and development of recurrent vomiting was 19.0 ± 3.7 years. Patients had a mean of 7.1 ± 4.3 emergency room visits, 5.0 ± 2.7 clinic visits, and 3.1 ± 1.9 admissions for this syndrome. All patients had visited at least one other hospital in addition to Beaumont Hospital. All patients had vomiting (mean vomiting episodes every 3.0 ± 1.7 h), compulsive bathing (mean = 5.0 ± 2.0 baths or showers/day; mean total bathing time = 5.0 ± 5.1 h/day), and abdominal pain. Seven patients took hot baths or showers, and seven patients experienced polydipsia. Four out of five patients who discontinued cannabis use recovered from the syndrome, while the other three patients who continued cannabis use, despite recommendations for cessation, continued to have this syndrome. Among those four who recovered, one patient had recurrence of vomiting and compulsive bathing with cannabis resumption.<h4>Conclusions</h4>Cannabis hyperemesis is characterized by otherwise unexplained recurrent nausea and vomiting, compulsive bathing, abdominal pain, and polydipsia associated with chronic cannabis use. This syndrome can occur in the United States as well as in Australia. Cannabis cessation may result in complete symptomatic recovery.