Inhibition of oral midazolam clearance by boosting doses of ritonavir, and by 4,4-dimethyl-benziso-(2H)-selenazine (ALT-2074), an experimental catalytic mimic of glutathione oxidase.

What Is Already Known About This Subject: * The viral protease inhibitor ritonavir is known to inhibit clearance of intravenous midazolam. * ALT-2074, a catalytic mimic of glutathione oxidase, inhibits human cytochrome P450 3A (CYP3A) isoforms in vitro.

What This Study Adds: * Short-term administration of low-dose ritonavir increases area under the plasma concentration curve following oral midazolam by a factor of 28.

Sitagliptin, an dipeptidyl peptidase-4 inhibitor, does not alter the pharmacokinetics of the sulphonylurea, glyburide, in healthy subjects.

Aims: Sitagliptin, a dipeptidyl peptidase-4 inhibitor, is an incretin enhancer that is approved for the treatment of Type 2 diabetes. Sitagliptin is mainly renally eliminated and not an inhibitor of CYP450 enzymes in vitro. Glyburide, a sulphonylurea, is an insulin sensitizer and mainly metabolized by CYP2C9.

Effect of food on the pharmacokinetics of a vildagliptin/metformin (50/1000 mg) fixed-dose combination tablet in healthy volunteers.

Objective: Vildagliptin is an orally active, potent and selective DPP-4 inhibitor that improves glycemic control in patients with type 2 diabetes by increasing alpha- and beta-cell responsiveness to glucose.

Research Design And Methods: This open-label, single-center, randomized, two-period crossover study in healthy subjects (n=23) ages 18-45 years investigated the effect of food on the pharmacokinetics of vildagliptin and metformin following administration of a vildagliptin/metformin (50/1000 mg) fixed-dose combination tablet.

Results: Administration of the fixed-dose combination tablet following a high-fat meal had no effect on vildagliptin AUC(0-infinity) (ratio of geometric mean for fed:fasted state, 1.

Pomegranate juice does not impair clearance of oral or intravenous midazolam, a probe for cytochrome P450-3A activity: comparison with grapefruit juice.

The effect of pomegranate juice (PJ) or grapefruit juice (GFJ) on CYP3A activity was studied in vitro and in healthy human volunteers. In human liver microsomes, the mean 50% inhibitory concentrations (IC(50)) for PJ and GFJ versus CYP3A (triazolam alpha-hydroxylation) were 0.61% and 0.

Interaction of flurbiprofen with cranberry juice, grape juice, tea, and fluconazole: in vitro and clinical studies.

Objectives: Recent anecdotal, unvalidated case reports have suggested potentiation of warfarin-induced anticoagulation by cranberry juice, possibly through inhibition of human cytochrome P450 (CYP) 2C9, the enzyme responsible for the clearance of the active S-enantiomer of warfarin. To address this question, the effect of cranberry juice and other beverages on CYP2C9 activity was evaluated in vitro and in vivo.

Methods: The effects of 4 beverages on CYP2C9 activity were studied in human liver microsomes, by use of flurbiprofen hydroxylation as the index reaction.