Global Benefit-risk Evaluation of Antidepressant Action: Comparison of Pooled Data for Venlafaxine, SSRIs, and Placebo.
Do antidepressants have an equivalent risk-benefit ratio? Venlafaxine, a serotonin-norepinephrine reuptake inhibitor, is an effective antidepressant for treating major depression. The results of some clinical studies have suggested that venlafaxine may have more potent efficacy in sustaining remission in patients with major depression. Comparative clinical studies, however, lack suitable power to discern treatment differences in safety and also lack a quantitative basis for comparing risk and benefit. A global benefit-risk analysis of pooled data from eight randomized, double-blind, clinical trials of the safety and efficacy of venlafaxine and selective serotonin reuptake inhibitors (SSRIs) was performed. By using the ratio measure of risk-benefit, patients treated with venlafaxine (n=851) for 6-8 weeks experienced a relative gain of 1.57 compared with SSRI-treated patients (n=743) and a relative gain of 2.27 compared with placebo-treated patients (n=439). Subgroup analyses showed a relative gain of 1.35 for venlafaxine-treated patients (n=538) compared with fluoxetine-treated patients (n=549) and a relative gain of 2.53 compared with placebo-treated patients (n=357). A dose-response relationship was apparent between low (<75 mg/day), medium (75-150 mg/day), and high (>150 mg/day) dosages of venlafaxine; r values were 0.758, 0.822, and 1.181, respectively (P=.023, high dosage versus placebo; P=.030, medium dosage versus placebo). Important differences in risk and benefit exist between venlafaxine and SSRIs as a group compared with fluoxetine alone. A significant gain in benefit-risk in the treatment of major depression was observed with an increase in venlafaxine dosage from 75->150 mg/day.
Entsuah
Richard
R
Department of Global Clinical Biostatistics, Wyeth Research, Collegeville, Pennsylvania, USA.
Gao
Bo
B