Venlafaxine, sold under the brand name Effexor among others, is an antidepressant medication of the serotonin-norepinephrine reuptake inhibitor (SNRI) class. It is used to treat major depressive disorder (MDD), generalized anxiety disorder (GAD), panic disorder, and social phobia. It is taken by mouth.
Common side effects include loss of appetite, constipation, dry mouth, dizziness, sweating, and sexual problems. Severe side effects include an increased risk of suicide, mania, and serotonin syndrome. Antidepressant withdrawal syndrome may occur if stopped. There are concerns that use during the later part of pregnancy can harm the baby. How it works is not entirely clear but it is believed to involve alterations in neurotransmitters in the brain.
Venlafaxine was approved for medical use in the United States in 1993. It is available as a generic medication. In the United States the wholesale cost per dose is less than US$0.20 as of 2018. In 2016 it was the 51st most prescribed medication in the United States with more than 15 million prescriptions.