Which 5-HT3 antagonist prevents nausea and vomiting in cesarean section more effectively: a network meta-analysis

INTRODUCTION: Selective 5-hydroxytryptamine 3 receptor (5-HT3) antagonists are commonly used to prevent nausea and vomiting (NV) after cesarean section, but the comparative efficacy of different 5-HT3 antagonists remains unclear. This network meta-analysis aimed to determine which 5-HT3 antagonists might be the preferred choice for preventing NV in parturient scheduled for elective cesarean delivery under spinal anesthesia. EVIDENCE ACQUISITION: PubMed, EMBASE, Cochrane library, and Web of Science were searched for relevant randomized controlled trials (RCTs) published before August 24, 2023. Random network meta-analysis was performed using Stata 14.0 to estimate the efficacy of different 5-HT3 antagonists in preventing intra- and post-operative NV. EVI DENCE SYNT HESIS : Twenty-eight studies involving seven dosing regimens of three 5-HT3 antagonists were included. Pooled results showed that ondansetron 12 mg was superior to other six dosing regimens in the prevention of postoperative NV (PONV), PON, and POV, with the ranking probability of 80.2%, 95.8%, and 87.7%, respectively, followed by granisetron two mg. Ondansetron 4 mg might be the first choice for preventing intraoperative NV (IONV) (92.8%), with the least use of postoperative rescue antiemetics (90.6%). Granisetron 3 mg and tropisetron 2 mg might be the best options for preventing ION and IOV, respectively. CONCLUSIONS: Based on available data, ondansetron 12 mg may have the best efficacy in preventing PONV, PON, and POV. Additionally, more studies are warranted to compare the safety of ondansetron 12 mg versus granisetron two mg.