Conclusions : International differences in prescriber behaviour may influence , and in turn be influenced by , the conduct of clinical trials .
Objective : International differences are thought to exist in dosages used by clinicians treating mood disorders .
This study examined international dosage differences in antidepressant clinical trials , using a data base formed and maintained as a component of a Cochrane review of comparative clinical trials of fluoxetine .
Venlafaxine compared with fluoxetine in outpatients with depression and concomitant anxiety.
The aim of this double-blind study was to compare the efficacy and safety of venlafaxine vs. fluoxetine in the treatment of patients with depression and anxiety . A total of 146 moderately depressed patients with associated anxiety were r and omized to receive 75 mg/d venlafaxine or 20 mg/d fluoxetine for 12 wk . Dose increases were permitted after 2 wk of treatment , to 150 mg/d venlafaxine and 40 mg/d fluoxetine , to optimize response . At the final visit , a statistically significantly greater efficacy of venlafaxine over fluoxetine was observed on depressive symptoms and concomitant anxiety , and 75.0 and 50.7 % of patients administered venlafaxine and fluoxetine , respectively , showed an overall response . A sustained response ( for at least 2 wk ) , present at the end of the study was achieved in 57.8 and 43.3 % of patients in the venlafaxine and fluoxetine groups , respectively , and at the final visit , 59.4 and 40.3 % of patients , respectively , were in remission ( virtually asymptomatic ) . Dose increases were required by a greater percentage of patients in the fluoxetine group ( 52.9 % ) , than in the venlafaxine group ( 37.1 % ) , and in those patients whose dose was increased , a higher efficacy was again observed with venlafaxine . Venlafaxine and fluoxetine were well tolerated , with the most frequently experienced adverse events being nausea and headache . Fewer patients in the venlafaxine group than in the fluoxetine group reported at least one adverse event ( 55.7 and 67.1 % patients , respectively ) . Venlafaxine therefore proved to be significantly more effective than fluoxetine in improving depressive symptoms and concomitant anxiety
Conclusions : International differences in prescriber behaviour may influence , and in turn be influenced by , the conduct of clinical trials .
Objective : International differences are thought to exist in dosages used by clinicians treating mood disorders .
This study examined international dosage differences in antidepressant clinical trials , using a data base formed and maintained as a component of a Cochrane review of comparative clinical trials of fluoxetine .