Desvenlafaxine (pristiq): a Selective Serotonin and Norepinephrine Reuptake Inhibitor

Volume 23, Issue 9 June 2008 1 Major depressive disorder (MDD) is characterized as a disabling psychiatric disorder, presenting with a loss of pleasure and interest in activities that normally bring satisfaction and enjoyment. MDD is a common disorder, roughly occurring at least once in the lifetime of 16.2% of US adults (32.6-35.1 million people), and at least once in the past year of 6.6% of US adults (13.1-14.2 million people). Studies show that being female, middle aged, divorced, low income, or Native American increase the risk of depression. Approximately 80% of depressed people are not currently treated and for those that are, antidepressants only work for 55-65% of them. In a group of studies evaluated by the FDA, placebos were approximately 80% as effective as the six leading antidepressant medications. Antidepressants work by attempting to correct a misbalance of neurotransmitters in the brain. Low levels of serotonin (5-HT) and norepinephrine (NE) can cause depressive symptoms and the correction of these deficiencies has been associated with an improvement of mood. Serotonin-Norepinephine Reuptake Inhibitors (SNRI) are a newer class of antidepressants that work on both neurotransmitters believed to play a major role in causing depression. Desvenlafaxine, by Wyeth Pharmaceuticals, Inc., is the third drug in the SNRI class and is the metabolite of venlafaxine. Desvenlafaxine was approved by the FDA in February of 2008, and is expected to be distributed in the second quarter of 2008. The only FDA approved indication for desvenlafaxine is for the treatment of MDD. Desvenlafaxine is also being investigated as the first nonhormonal treatment for vasomotor symptoms attributed to menopause; however, that is not a currently approved indication. The objective of this article is to review the pharmacology, pharmacokinetics, dosing, and toxicity of desvenlafaxine. In addition, a summary of clinical trials will be discussed.