Effects of Sleeve Gastrectomy and Roux-en-Y Gastric Bypass on Escitalopram Pharmacokinetics: A Cohort Study

BACKGROUND: Changes in the gastrointestinal physiology after bariatric surgery may affect the pharmacokinetics of medications. Data on the impact of different surgical techniques on the pharmacokinetics of commonly prescribed antidepressants such as escitalopram are limited. METHODS: This case-only prospective study investigated escitalopram-treated patients who underwent bariatric surgery at hospitals in Central Norway. Escitalopram concentrations were assessed using serial blood samples obtained during a dose interval of 24 hours preoperatively and at 1, 6, and 12 months, postoperatively. The primary outcomes were changes in the area under the time–concentration curve (AUC(0-24)) with secondary outcomes, including full pharmacokinetic profiling. We performed repeated-measures analysis of variance for the AUC(0-24) and secondary outcomes. RESULTS: Escitalopram-treated obese patients who underwent sleeve gastrectomy (n = 5) and Roux-en-Y gastric bypass (n = 4) were included. Compared with preoperative baseline, dose-adjusted AUC(0-24) values were within ±20% at all time points, postoperatively in the sleeve gastrectomy and oux-en-Y gastric bypass groups, with the largest changes occurring 1 month postoperatively (+14.5 and +17.2%, respectively). No statistically significant changes in any pharmacokinetic variables over time were reported; however, there was a trend toward increased maximum concentrations after surgery (P = 0.069). CONCLUSIONS: Our findings suggest that bariatric surgery has no systematic effect on the pharmacokinetics of escitalopram. However, because of the substantial interindividual variation, therapeutic drug monitoring can be considered to guide postoperative dose adjustments.