Comparison of the effectiveness of ondansetron versus metoclopramide in hyperemesis gravidarum: a randomized clinical trial

Objective: Nausea and vomiting are the most common complications and the first cause of hospitalization of pregnant women in the first trimester of pregnancy. Given the maternal and fetal complications as well as the negative psychosocial and economic effects of nausea and vomiting, the present study aimed to compare the antiemetic effects of ondansetron and metoclopramide. Methods: The present double-blind randomized clinical trial study was conducted on 153 pregnant women with a complaint of nausea and vomiting during pregnancy referred to the obstetrics and gynecology ward. Patients were randomly divided into two metoclopramide and ondansetron groups. The outcomes of interest were nausea and vomiting, the number of used doses of the drug, and the length of hospital stay. The Pregnancy-Unique Quantification of Emesis (PUQE) questionnaire was used to assess the severity of nausea and vomiting. Results: The mean age was significantly higher in the metoclopramide group (28.44 +/- 6.45 vs. 25.43 +/- 5.42 years, P=0.004). On day 3, the PUQE score was significantly higher in the ondansetron group (6.60 +/- 1.10 vs. 6.56 +/- 0.88, P<0.001). The decrease in the severity of nausea and vomiting was significantly higher in the ondansetron group (5.29 +/- 1.35 vs. 4.90 +/- 1.17, P=0.05) in the second day compared to the first day. In the repeated measure analysis, significant differences were found between the two treatment groups (F=7.01, P=0.009). There was no significant difference between the two groups in terms of the length of hospital stay (P>0.05). Conclusion: In this study, ondansetron revealed more efficacy than metoclopramide on the nausea and vomiting of pregnancy (NVP) management. Ondansetron may, therefore, be considered as a safe and effective alternative for metoclopramide in the treatment of NVP.