Dopamine antagonists and topical capsaicin for cannabis hyperemesis syndrome (CHS) in the emergency department: a systematic review of direct evidence

Abstract

AbstractBackgroundAdults with cannabis hyperemesis syndrome (CHS) are increasingly presenting to the emergency department (ED) and this systematic review will evaluate the direct evidence on the effectiveness of capsaicin and dopamine antagonists in its clinical management.MethodsA bibliographic search was conducted to address the following population‐intervention‐control‐ outcome (PICO) question: (P) Adults >18 years old with a diagnosis of acute CHS presenting to the ED; (I) dopamine antagonists (e.g. haloperidol, droperidol) and topical capsaicin; (C) usual care or no active comparator; (O) symptoms improvement/resolution in ED, ED length of stay, admission rate, ED recidivism, need for rescue medication, adverse events. This systematic review was conducted in accordance with PRISMA reporting recommendations.ResultsFrom 53 potentially relevant articles, 7 articles were included: 5 observational studies and 2 randomized controlled trials (RCTs), including a total of 492 patients. Five of these studies evaluated the efficacy of capsaicin cream (n=386), two examined dopamine antagonists (haloperidol, droperidol; n=106). There was mixed evidence for the efficacy of capsaicin for reducing nausea and emesis. Both studies evaluating dopamine antagonists detected clinical benefit to usual care or no active comparator.ConclusionsThere is limited direct evidence on the efficacy of dopamine antagonists or capsaicin for treating CHS in the ED. Current evidence is mixed for capsaicin and potentially beneficial for dopamine antagonists. Because of the small number of studies, small number of participants, lack of standardization of treatment administration, and risk of bias of the included studies, methodologically rigorous trials on both types of intervention are needed to directly inform ED management of CHS.