Ondansetron versus gabapentin in preventing postoperative nausea and vomiting after laparoscopic sleeve gastrectomy: a randomized study.

Despite the use of costly serotonin (5-HT3) receptor antagonists, preventing postoperative nausea and vomiting (PONV) particularly after laparoscopic sleeve gastrectomy (LSG) remains challenging. This study was aimed at evaluating the impact of ondansetron versus gabapentin in preventing PONV in morbidly obese patients underwent LSG. In this double-blind placebo controlled parallel study, 100 morbidly obese patients who were scheduled for LSG were randomized into two groups; group 1 (n = 50) which received intravenous ondansetron 8 mg before surgery and group 2 (n = 50) which received 600 mg oral gabapentin an hour before the anticipated time of surgery. The severity of PONV using the Rhodes index and the percentage of complete response as well as intensity of pain using visual analogue scale (VAS) scores during the first 48 h were evaluated alongside with the assay of serum levels of substance P, serotonin, and vasopressin at baseline, and 24 h after surgery. The severity of PONV was comparable between both groups during the first 2 h and from 2 to 24 h postoperatively. However, fewer patients in the gabapentin group required rescue antiemetics within 24 h (P = 0.001). Gabapentin was also associated with significantly lower serum levels of both vasopressin (P = 0.001) and substance P (P = 0.014), with no difference in serotonin levels between groups. Pain intensity was significantly lower in gabapentin group at 0-2 h, 6 h, and 12 h, but not at 24 or 48 h. Based on the safety profile and known analgesic property, gabapentin could represent a cost-effective prophylactic agent for PONV in patients undergoing LSG. Clinical trial registration: ClinicalTrials.gov Identifier: NCT05620641 (11/11/2022).