CYP2B6 and chronic kidney disease: They were unable to show a direct effect of CKD on BUP metabolism but did record increases in half‐life and area under the plasma‐concentration time curve (AUC) (140% and 126%, respectively) corresponding with an apparent reduction in clearance of 63% in CKD patients.42 Based on experimental conditions the evidence suggested that CYP2B6 activity was decreased, but the authors could not unequivocally state this claim.