The treatment of depression with different formulations of venlafaxine: A comparative analysis

Abstract

Venlafaxine is the first of a group of antidepressants that show dual reuptake inhibition of serotonin and noradrenaline (SNRIs). Originally marketed in an immediate release (IR) formulation a microencapsulated, extended release (XR) formulation is now available. Significant differences exist between these two formulations with respect to pharmacokinetic parameters which have an impact on clinical use. The XR has lower maximum plasma concentrations (Cmax) and achieves-these at a later time (higher Tmax). The longer apparent elimination half-life of the drug after single XR doses suggests that it is suitable for once daily dosing compared with the twice daily dosing regimen required by the IR..