Venlafaxine (Effexor): concerns about increased risk of fatal outcomes in overdose

摘要

Reason for posting: A change in the prescribing information for venlafaxine has been issued by the US manufacturer, based on concerns that the anti-depressant drug has been associated, in cases of overdose, with an increased risk of death compared with selective serotonin reuptake inhibitors (SSRIs). The drug: Venlafaxine, a serotonin and noradrenalin reuptake inhibitor, is widely used in Canada for the treatment of DSM-IV-defined major depressive, generalized anxiety and social anxiety disorders in adults. It is generally well tolerated but shares several of the adverse effects of SSRJs, including gastrointestinal upset, sweating, dry mouth, sedation and sexual dysfunction. Additionally, venlafaxine has a known association with blood pressure elevation in some 3%-4% of patients who use the sustained release format and 2%-13% of those who take the immediate-release preparation. Concerns about a higher fatality rate in overdose has emerged over the past 4 years from information provided by administrative database studies.