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 .
The Delay of Gastric Emptying Induced by Remifentanil Is Not Influenced by Posture
Posture has an effect on gastric emptying . In this study , we investigated whether posture influences the delay in gastric emptying induced by opioid analgesics . Ten healthy male subjects underwent 4 gastric emptying studies with the acetaminophen method . On two occasions the subjects were given a continuous infusion of remifentanil ( 0.2 μg · kg−1 · min−1 ) while lying either on the right lateral side in a 20 ° head-up position or on the left lateral side in a 20 ° head-down position . On two other occasions no infusion was given , and the subjects were studied lying in the two positions . When remifentanil was given , there were no significant differences between the two postures in maximal acetaminophen concentration ( right side , 34 μmol · L−1 ; versus left side , 16 μmol · L−1 ) , time taken to reach the maximal concentration ( 94 versus 109 min ) , or area under the serum acetaminophen concentration time curve from 0 to 60 min ( 962 versus 197 min · μmol · L−1 ) . In the control situation , there were differences between the postures in maximal acetaminophen concentration ( 138 versus 94 μmol · L−1 ; P < 0.0001 ) and area under the serum acetaminophen concentration time curves from 0 to 60 min ( 5092 versus 3793 min · μmol · L−1 ; P < 0.0001 ) , but there was no significant difference in time taken to reach the maximal concentration ( 25 versus 47 min ) . Compared with the control situation , remifentanil  delayed gastric emptying in both postures . We conclude that remifentanil  delays gastric emptying and that this delay is not influenced by posture
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 .