Urinary Cannabis Metabolite Concentrations in Cannabis Hyperemesis Syndrome.
Cannabis Hyperemesis Syndrome (CHS) is characterized by recurrent episodes of intractable emesis associated with heavy use of cannabis. Recognition of CHS can be problematic due to the lack of specific biomarkers, which can point the clinician to the diagnosis. We present, retrospectively, a series of adolescentyoung adult patients who presented to a pediatric gastroenterology (GI) service with acute on chronic nausea and vomiting, subsequently found to have CHS with associated elevated urinary cannabis metabolite concentrations. We describe 15 patients referred to our pediatric GI division for intractable emesis with spot urinary cannabis metabolite carboxy-THC (THC-COOH) concentrations from January 1, 2018 through April 20, 2019. Urinary testing was performed using gas chromatography mass-spectrometry (GC-MS) in a manner consistent with Clinical Laboratory Improvement Amendments (CLIA) requirements at Mayo Clinic laboratory (Rochester, MN). The laboratory cutoffs were 3.0 ngmL. Data was extracted via chart review and analyzed via online statistical application. Fifteen patients (seven females, eight males) were studied with an average age of 17.7 years. All patients reported frequent cannabis use for at least 1 month and exhibited intractable, non-bilious emesis for at least 2 weeks. Twelve patients also reported weight loss. Two patients had underlying gastrointestinal disease (one with Crohn disease and one with irritable bowel syndrome). All patients had essentially normal GI workup including laboratory tests, imaging studies and endoscopies.Fourteen of 15 patients had urinary THC-COOH concentrations >100 ngmL, with seven individuals exhibiting levels >500 ngmL. One patient had a urinary TCH-COOH concentration level under 100 ngmL had not used cannabis for 2 weeks. Most other patients had used cannabis within 2 days of providing a urine sample. The Binomial test for CHS patients with urinary THC-COOH levels over 100 ngmL was significant with a P-value of <0.0005 (one tail test). CHS is associated with an elevated urinary THC-COOH level usually exceeding 100 ngmL, which is indicative of significant chronic cannabis exposure. In patients with a history consistent with CHS, urine THC-COOH testing may help guide the diagnostic evaluation of these patients and decrease the need for further workup.