Remission rates with venlafaxine extended release in Greek outpatients with generalized anxiety disorder. A double-blind, randomized, placebo controlled study

The primary endpoints in this study were the remission rates [final Hamilton Rating Scale for Anxiety (HAM-A) total score < or =7] and reduction from baseline in the HAM-A total score in patients with generalized anxiety disorder (GAD) and no associated depression. Patients with GAD (DSM-IV and HAM-A total score >18) were randomly assigned to treatment with venlafaxine XR or placebo for 8 weeks. A 1-week placebo run-in period preceded the double-blind phase. Patients with a >20% drop in their total HAM-A score during the run-in period, were excluded from the double-blind phase. All patients started therapy with 75 mg/day venlafaxine XR or matched placebo. Patients with less than 30% decrease in their HAM-A total score at the end of the second week, doubled their dose. Patients on the 150 mg/day dose underwent a 1-week taper period. Of the 24 patients in the venlafaxine XR group, 62.5% achieved remission versus 9.1% in the placebo group (P=0.0006). The mean decrease from baseline in HAM-A total score was 19.2 points for the venlafaxine XR group and 10.8 points for the placebo group (P<0.001). Eleven placebo-treated patients and seven venlafaxine XR treated patients doubled their dose at the end of the second week of double-blind treatment. No patient interrupted therapy because of side-effects. No changes in systolic or diastolic blood pressure were observed. Venlafaxine XR 75-150 mg/day was well tolerated. The remission rates achieved with venlafaxine 75-150 mg/day in non-depressed GAD patients were high with good tolerability.