59: Ondansetron versus doxylamine/pyridoxine for treatment of nausea and vomiting in pregnancy: a prospective randomized double-blind trial


      To determine whether ondansetron or the combination of doxylamine plus pyridoxine was superior for treatment of nausea and vomiting of pregnancy (NVP).

      Study Design

      We performed a prospective, randomized, double blind trial of women in early pregnancy requesting treatment for NVP. Before treatment, subjects graded their nausea and emesis on two visual analog scales (VAS). Subjects were then randomized to receive either: 4mg ondansetron plus a placebo tablet or 25 mg pyridoxine plus 12.5 mg doxylamine every 8 hours for 5 days. A VAS was repeated 5-7 days after initiating the regemin to assess nausea and vomiting. Any adverse effects of the treatments were recorded. The primary outcome was reduction in nausea on the VAS by 25mm. Secondary outcomes were reduction in vomiting on the VAS and number of patients reporting sedation or constipation.


      A total of 36 women were enrolled with 30 fully completing the study. Demographics were not significantly different between the two groups. Patients randomized to ondansetron demonstrated a greater reduction in nausea as compared to those taking pyridoxine and doxylamine (p < .05). Furthermore, women taking ondansetron reported less vomiting (p = .05). There was no significant difference between the groups with respect to sedation or constipation (p >0.05).


      Ondansetron was superior to the combination of pyridoxine and doxylamine for the reduction of nausea and vomiting occurring in the first trimester of pregnancy.