Effect of Roux-en-Y gastric bypass on the bioavailability of metoprolol from immediate and controlled release tablets: a single oral dose study before and after surgery.

Objective: Roux-en-Y gastric bypass (RYGB) surgery induces major changes in the gastrointestinal tract that may alter the pharmacokinetics of orally administered drugs. Results from pharmacokinetic studies are sparse. This study aimed to investigate the effect of RYGB on the bioavailability of metoprolol from immediate release (IR) and controlled release (CR) tablets in female patient volunteers before and after surgery.

A clinical validation study for application of DBS in therapeutic drug monitoring of antidepressants.

Background: A bridging study of plasma and DBS concentrations for therapeutic drug monitoring of antidepressants was performed. RESULTS & METHODOLOGY: Potassium-based hematocrit analysis was included. In addition, we defined acceptance criteria based on the differences between individual data points of plasma and DBS concentrations.