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 .
Co-administration of rivaroxaban with drugs that share its elimination pathways: pharmacokinetic effects in healthy subjects.
AIMS The anticoagulant rivaroxaban is an oral , direct Factor Xa inhibitor for the management of  thromboembolic disorders .  Metabolism and excretion involve cytochrome P450 3A4 ( CYP3A4 ) and 2J2 ( CYP2J2 ) , CYP-independent mechanisms , and P-glycoprotein ( P-gp ) and breast cancer resistance protein ( Bcrp ) ( ABCG2 ) . METHODS The pharmacokinetic effects of substrates or inhibitors of CYP3A4 , P-gp and Bcrp ( ABCG2 ) on rivaroxaban were studied in healthy volunteers . RESULTS Rivaroxaban did not interact with midazolam ( CYP3A4 probe substrate ) . Exposure to  rivaroxaban when co-administered with midazolam was slightly decreased by 11 % ( 95 % confidence interval [ CI ] -28 % , 7 % ) compared with rivaroxaban alone . The following drugs moderately affected  rivaroxaban  exposure , but not to a clinical ly relevant extent : erythromycin ( moderate CYP3A4/P-gp inhibitor ; 34 % increase [ 95 % CI 23 % , 46 % ] ) , clarithromycin ( strong CYP3A4/moderate P-gp inhibitor ; 54 % increase [ 95 % CI 44 % , 64 % ] ) and fluconazole ( moderate CYP3A4 , possible Bcrp [ ABCG2 ] inhibitor ; 42 % increase [ 95 % CI 29 % , 56 % ] ) . A significant increase in  rivaroxaban exposure was demonstrated with the strong CYP3A4 , P-gp/Bcrp ( ABCG2 ) inhibitors ( and potential CYP2J2 inhibitors ) ketoconazole ( 158 % increase [ 95 % CI 136 % , 182 % ] for a 400 mg once daily dose ) and ritonavir ( 153 % increase [ 95 % CI 134 % , 174 % ] ) . CONCLUSIONS Results suggest that rivaroxaban may be co-administered with CYP3A4 and /or P-gp substrates/moderate inhibitors , but not with strong combined CYP3A4 , P-gp and Bcrp ( ABCG2 ) inhibitors ( mainly comprising azole-antimycotics , apart from fluconazole , and HIV protease inhibitors ) , which are multi-pathway inhibitors of rivaroxaban clearance and elimination
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 .