In the case of the majority of studied drugs , an increased absorption rate was observed early after RYGBP .
The effect on systemic exposure allows for a low degree of extrapolation , including between drugs subjected to the same major metabolic and transporter pathways .
Anatomical changes in the gastrointestinal tract and subsequent weight loss may influence drug disposition and thus drug dosing following bariatric surgery .
This review systematic ally examines the effects of bariatric surgery on drug pharmacokinetics , focusing especially on the mechanisms involved in restricting oral bioavailability .
Significant Increase in Systemic Exposure of Atorvastatin After Biliopancreatic Diversion With Duodenal Switch
Biliopancreatic diversion with duodenal switch is a combined restrictive and malabsorptive surgical weight loss procedure . Given that this procedure introduces a bypass of the proximal small intestine , it is a suitable model for investigating the influence of the proximal intestine on drug bioavailability . Eight‐hour pharmacokinetic profiles were obtained the day before surgery and again after surgery at ( median ) 6 weeks ( range , 4–8 weeks ) in 10 morbidly obese patients who were receiving treatment with 20–80 mg atorvastatin each morning .  The bioavailability of atorvastatin  acid was significantly increased , with a mean twofold higher AUC0–8 after surgery ( range 1.0–4.2 , P = 0.001 ) . Time to maximum plasma concentration ( Cmax ) increased from 1.2 h before surgery to 2.3 h after surgery ( P = 0.03 ) . The results emphasize the protective nature of the proximal small intestine against ingested exogenous compounds . Consequently , retitration to the lowest effective dose should be considered after biliopancreatic diversion with duodenal switch in the case of drugs with a high degree of intestinal first pass metabolism and a narrow therapeutic window
In the case of the majority of studied drugs , an increased absorption rate was observed early after RYGBP .
The effect on systemic exposure allows for a low degree of extrapolation , including between drugs subjected to the same major metabolic and transporter pathways .
Anatomical changes in the gastrointestinal tract and subsequent weight loss may influence drug disposition and thus drug dosing following bariatric surgery .
This review systematic ally examines the effects of bariatric surgery on drug pharmacokinetics , focusing especially on the mechanisms involved in restricting oral bioavailability .