Desvenlafaxine in the treatment of major depressive disorder

Major depressive disorder (MDD) is among the most incapacitating conditions in the world. The emergence of the selective serotonin reuptake inhibitor (SSRI) and serotonin norepinephrine reuptake inhibitors (SNRI) antidepressants has improved the treatment of MDD. Desvenlafaxine succinate (DVS) is the succinate salt of the isolated major active metabolite of venlafaxine, O-desmethylvenlafaxine: it is the third SNRI to become available in the United States, and was approved in 2008 by the US Food and Drug Administration (FDA) for the treatment of MDD. Early investigations showed therapeutic efficacy for doses between 50 and 400 mg/day; however in doses above 100 mg/day there were incremental increases in side effects. Nausea was the most frequent adverse effect. Hence the recommended dosing for DVS is in the 50 to 100 mg range. Desvenlafaxine is excreted in urine, it is minimally metabolized via the CYP450 pathway, and is a weak inhibitor of CYP2D6. A reduced risk for pharmacokinetic drug interactions is a potential advantage over other SNRI. Further head-to-head trials involving comparisons of DVS in the 50 to 100 mg dose range with currently available SSRI and SNRI antidepressants are required. Evidence for relapse prevention is available in the 200 to 400 mg dose range, but this needs to be demonstrated in the 50 to 100 mg dose range, as well as health economic measures and quality of life evaluations.