Effect of a Roux-en-Y Gastric Bypass on the Pharmacokinetics of Oral Morphine Using a Population Approach

Background and Objectives Obesity and opioid use for chronic pain in obese individuals are both important public health concerns. The pharmacokinetics of oral morphine after Roux-en-Y gastric bypass (RYGB) are unknown. Therefore, we aimed to study the pharmacokinetics of oral morphine in morbidly obese patients before and after RYGB surgery, to identify the effects of RYGB and the subsequent reversal of morbid obesity on the pharmacokinetic parameters of morphine.