Population pharmacokinetics and Monte Carlo simulations demonstrated similar pharmacokinetics of risperidone in children, adolescents and adults.

No abstract

Many patients with acute coronary syndrome receive chronic dual antiplatelet therapy (acetylsalicylic acid and clopidogrel) for secondary event prophylaxis, and new oral anticoagulants are being investigated as adjunctive therapy in this indication. Gastrointestinal side effects such as bleeding are commonly associated with antiplatelet use; accordingly, many patients receive proton pump inhibitors (PPIs) to mitigate this. PPIs can reduce the antiplatelet activity of clopidogrel through cytochrome P450 2C19 inhibition, and pantoprazole reduces the bioavailability of dabigatran, a direct thrombin inhibitor that acts via cytochrome P450 2C19-independent mechanisms. These observations support the investigation of potential pharmacokinetic and pharmacodynamic interactions between PPIs and anticoagulants. We evaluated the influence of administering once-daily omeprazole 40 mg for 5 days on the pharmacokinetics and pharmacodynamics of a single 20-mg dose of the oral direct factor Xa inhibitor, rivaroxaban, in a randomized, open-label, 2-way, crossover, drug-drug interaction study in healthy subjects. No clinically meaningful interactions were observed; geometric mean ratios were 101%, 101%, and 93.5% for rivaroxaban area under the plasma concentration-time curve from time 0 to the time of the last quantifiable concentration (AUClast), or until infinity (AUC∞), and maximum plasma concentration (Cmax), respectively. Prothrombin time increased similarly in both treatment groups, with maximal values observed approximately 4 hours post rivaroxaban administration. A single 20-mg rivaroxaban dose appears well tolerated when administered alone or after 5 days of once-daily omeprazole 40 mg administration.

Dapoxetine is a short-acting selective serotonin reuptake inhibitor developed for the on-demand treatment of premature ejaculation and is approved in some European Union countries, as well as Mexico and Korea, for this indication. The pharmacokinetics of dapoxetine 30 mg and 60 mg in healthy Chinese (single dose), Japanese, and Caucasian men (single and multiple dose) were assessed in 2 studies. In the 3 ethnic groups, dapoxetine was rapidly absorbed following oral administration, with peak plasma concentrations evident approximately 1 hour after dosing, independent of dose, dosing frequency (single or multiple dosing), or ethnicity. Dapoxetine was eliminated in a biphasic manner with an apparent mean terminal half-life of 14 to 17 hours. There was a dose-proportional increase in dapoxetine maximum plasma concentration (C(max)) and area under concentration-time curves (AUCs). The single-dose pharmacokinetic parameters of dapoxetine metabolites were also similar for the 3 ethnic groups, as were the pharmacokinetics of dapoxetine and its metabolites following single and multiple dosing in Caucasian and Japanese men. Dapoxetine was well tolerated by all 3 ethnic groups.