Rosuvastatin and Losartan Pharmacokinetics After Bariatric Surgery

This prospective, open-label, non-randomized pharmacokinetic study will evaluate how Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy affect systemic exposure to single oral test doses of rosuvastatin and losartan. Sixty adults scheduled for bariatric surgery will enter one of two parallel groups according to the clinically selected operation (30 RYGB and 30 sleeve gastrectomy). Each participant will receive rosuvastatin 10 mg and losartan 25 mg once within 30 days before surgery and again approximately 12 weeks after surgery. Plasma samples collected before dosing and at 1.5 and 4 hours after dosing will be used with maximum a posteriori Bayesian estimation to estimate individual pharmacokinetic parameters. In the 30-participant RYGB group only, paired stool samples will be used to explore gut microbiota and untargeted fecal metabolomic changes. The primary objective is to compare within-participant changes and between-procedure differences in drug exposure after bariatric surgery.