Marijuana, Ondansetron, and Promethazine Are Perceived as Most Effective Treatments for Gastrointestinal Nausea

Background: Many anti-nausea treatments are available for chronic gastrointestinal syndromes, but data on efficacy and comparative effectiveness are sparse.

Aims: To conduct a sectional survey study of patients with chronic nausea to assess comparative effectiveness of commonly used anti-nausea treatments.

Methods: Outpatients at a single center presenting for gastroenterology evaluation were asked to rate anti-nausea efficacy on a scale of 0 (no efficacy) to 5 (very effective) of 29 commonly used anti-nausea treatments and provide other information about their symptoms. Additional information was collected from the patients’ chart. The primary outcome was to determine which treatments were better or worse than average using a t test. The secondary outcome was to assess differential response by individual patient characteristics using multiple linear regression.

Results: One hundred and fifty-three patients completed the survey. The mean efficacy score of all anti-nausea treatments evaluated was 1.73. After adjustment, three treatments had scores statically higher than the mean, including marijuana (2.75, p < 0.0001), ondansetron (2.64, p < 0.0001), and promethazine (2.46, p < 0.0001). Several treatments, including many neuromodulators, complementary and alternative treatments, erythromycin, and diphenhydramine had scores statistically below average. Patients with more severe nausea responded better to marijuana (p = 0.036) and diphenhydramine (p < 0.001) and less so to metoclopramide (p = 0.020). There was otherwise no significant differential response by age, gender, nausea localization, underlying gastrointestinal cause of nausea, and GCSI.

Conclusions: When treating nausea in patients with chronic gastrointestinal syndromes, clinicians may consider trying higher performing treatments first, and forgoing lower performing treatments. Further prospective research is needed, particularly with respect to highly effective treatments.