Comparative antiemetic efficacy of metoclopramide, ondansetron and pyridoxine for the prevention nausea and vomiting in patients undergoing cesarean section under spinal anesthesia

Introduction. One of the complications after Cesarean Section is nausea and vomiting, especially during spinal anesthesia. The main causes of nausea and vomiting are complex, and may be related to surgical intervention, decrease in blood pressure, vagal excitation, and oxytocin administration. The objective was to compare and estimate the efficacy of intravenous injections of ondansetron, pyridoxine and metoclopramide in inhibiting emesis prophylactically in patients undergoing cesarean section under spinal anesthesia. Materials and methods. This study included 100 pregnant females in the last term without significant concomitant pathology of ASA grades I and II. Patients were randomly allocated into three drug groups and a control group. Each group consisted of 25 patients: the ondansetron group (4 mg intravenously), the metoclopramide group (10 mg intravenously), the pyridoxine group (100 mg intravenously), and the placebo group or the control group (normal saline - 2 ml intravenously). During the study, nausea and vomiting occurred during and after surgery, in addition to any additional adverse effects. Statistical software (SPSS 20.0) was used for statistical data analysis. Results. The incidence of intra- and postoperative nausea and vomiting was higher in the placebo group (40% and 32%) compared with the ondansetron group (4% and 8%), the metoclopramide group (8% and 16%), and the pyridoxine group (20% and 24%). Signs of gastrointestinal disorders were more pronounced in the pyridoxine group compared with the metoclopramide and ondansetron groups. The incidence of nausea and vomiting after surgery was high in the placebo group and statistically significant compared with the ondansetron group (p = 0.0232), there was no statistically significant difference with the metoclopramide and ondansetron groups. Conclusion. According to the results of the study, ondansetron and metoclopramide were more effective in reducing nausea and vomiting than pyridoxine and placebo. Ondansetron was significantly more effective for prevention of both intra- and postoperative nausea and vomiting.