Intravenous ondansetron to prevent hypotension during cesarean section under spinal anaesthesia

Background: Spinal anesthesia for cesarean section (CS) is associated with common side effects like hypotension and bradycardia. Ondansetron, a 5HT3 receptor antagonist, inhibits Bezold-Jarish reflex and has been found to be effective for prevention of spinal-induced hypotension for elective cesarean section. Aims: The aim of this study was to evaluate the effect of two different doses of ondansetron as prophylaxis to prevent hypotension during spinal anesthesia for caesarean section. Materials and Methods: This prospective randomized double-blinded controlled study was conducted on 150 full-term parturients undergoing CS under spinal anesthesia, who were divided into three groups, receiving saline or different drug doses: Group C: 0.9% Normal Saline 10 ml; Group O4: 4 mg Ondansetron in 8 ml NS; or Group O8: 8 mg Ondansetron in 6 ml NS, 5 min before spinal anesthesia. All the patients were monitored for blood pressure, heart rate, vasopressor requirement, and side effects. Hemodynamic variables and demographic data were compared by analysis of variance (ANOVA) and Chi-square test was used for analyzing adverse effects and P value