Ethanol pharmacokinetics before and after sleeve gastrectomy and Roux-en-Y gastric bypass: a 3 year prospective study (the BAR-TRIAL)

Abstract Objectives To compare ethanol pharmacokinetics before and after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) over a three-year period. Methods This was a prospective, longitudinal, non-randomized controlled study at St. Olavs Hospital, Trondheim, including 33 adults without histories of alcohol use disorder (RYGB: n = 14; SG: n = 19). Participants underwent oral and intravenous ethanol challenge tests preoperatively and at 3, 12, and 36 months postoperatively. Primary outcomes included maximum plasma concentration (C max ), time to reach maximum concentration (T max ), and area under the curve to the last measurable concentration (AUC last ). Results The ethanol uptake after both surgical procedures was bioequivalent for AUC last , but not for C max and T max . At 12 months, RYGB gave a 27% higher C max and 31% shorter T max than SG, while no significant differences were observed for AUC last . Both procedures induced profound and persistent alterations in ethanol pharmacokinetics over the three-year period: C max and AUC last approximately doubled, and T max was reduced to about half the preoperative value. C max occurred within 9–15 min compared to 25–29 min before surgery. Patients also had concomitant reductions in total body water, averaging 3.2 kg after SG and 4.8 kg after RYGB at 12 months. Conclusion Both RYGB and SG permanently altered ethanol pharmacokinetics, resulting in faster absorption, higher peak concentrations, and higher systemic exposure of alcohol. These changes, which were more pronounced after RYGB, may increase the risk of alcohol use disorders post-surgery. Awareness of the pharmacokinetic effects on RYGB and SG may be relevant for patient education, surgical decision-making, and postoperative monitoring. Clinical trial registration This study was registered in ClinicalTrials.gov on May 15 2013. Identifier: NCT01840020.