Efficacy and tolerance of venlafaxine in depressed patients switched from prior antidepressant treatment

Abstract

A large-scale, naturalistic trial was conducted in 1020 patients, 688 of whom switched to venlafaxine from other antidepressant medications, primarily because of lack of efficacy with their prior antidepressant (86.3% patents). A significant decrease from baseline in Hamilton Rating Scale for Depression (HAM-D) and Montgomery Asberg Depression Rating Scale (MADRS) scores occurred at each study visit (weeks 2-6). An increasing percentage of patients were classified as responders over the course of the study (>50% by week 6), with approximately 20% of patients in early remission and approximately 40% classed as having a sustained response. A higher percentage of patients previously treated with selective serotonin reuptake inhibitors (SSRIs) were classified as responders at week 6 than those treated with tricyclic antidepressants or combination or other antidepressant medication. One-way analyses of variance of the final change from baseline revealed that these differences were statistically significant for bot h HAM-D and MADRS scores. The same result held for the subset of patients switched due to lack of efficacy. Amongst specific SSRIs, the final change from baseline revealed no significant differences between the SSRIs for HAM-D or MADRS scores. Venlafaxine was safe and well tolerated and switching patents to venlafaxine from other antidepressants did not affect the incidence or type of adverse events. No evidence of serotonin discontinuation syndrome was seen during the study. In conclusion, venlafaxine was effective as switch therapy for patients with previous antidepressant treatment.