Desvenlafaxine succinate for major depressive disorder.

Desvenlafaxine (O-desmethylvenlafaxine) is the major active metabolite of venlafaxine. Desvenlafaxine succinate is now undergoing active evaluation for its therapeutic efficacy in a variety of disorders, including major depressive disorder, vasomotor symptoms associated with menopause, fibromyalgia and diabetic neuropathy. Desvenlafaxine is a serotonin and norepinephrine reuptake inhibitor (SNRI) with similar activity to its parent compound venlafaxine, and little affinity for other brain targets, including muscarinic, cholinergic, histamine H(1) and alpha-adrenergic receptors. Desvenlafaxine has linear pharmacokinetics, low protein binding, a half-life of approximately 10 hours and is metabolized primarily via glucuronidation, and to a minor extent through CYP3A4. The desvenlafaxine succinate formulation appears to have good oral bioavailability. Clearance rates are reduced in the elderly, those with severe renal dysfunction and those with moderate to severe hepatic dysfunction, which may require dosage adjustments. Three published clinical trials have shown supportive but mixed results for the efficacy of desvenlafaxine in the treatment of major depressive disorder with daily doses ranging from 100 mg to 400 mg. One published clinical trial has shown mixed results for the efficacy of desvenlafaxine in the treatment of vasomotor symptoms associated with menopause with daily doses ranging from 50 mg to 200 mg. In these four clinical trials, desvenlafaxine was associated with several mild adverse effects, with the most common effect being nausea. Less common, but more serious, adverse effects reported in these trials included hypertension, QTc interval prolongation, exacerbation of ischemic cardiac disease, elevated lipids and elevated liver enzymes. The exact nature of these serious adverse effects, including the prevalence, clinical significance and potential risk factors, still needs to be fully elucidated. Desvenlafaxine has a low propensity for pharmacokinetic-based drug interactions, although it has the same potential for pharmacodynamic interactions as other serotonin-norepinephrine reuptake inhibitors. Desvenlafaxine is currently another treatment option for major depressive disorder. The only identified potential advantage of desvenlafaxine over venlafaxine or other antidepressant agents at this time is the apparently reduced risk for pharmacokinetic drug interactions.