Context: No large-scale posttraumatic stress disorder drug trials have been conducted to evaluate treatment effects beyond 12 weeks outside of those with selective serotonin reuptake inhibitors.
Objective: To evaluate the efficacy of venlafaxine extended release (ER), a serotonin norepinephrine reuptake inhibitor, in posttraumatic stress disorder.
Design: 6-month, double-blind, placebo-controlled trial.
Setting: International study at 56 sites. Patients Adult outpatients (N = 329) with a primary diagnosis of posttraumatic stress disorder as defined in the DSM-IV, symptoms for 6 months or longer, and a 17-item Clinician-Administered Posttraumatic Stress Disorder Scale score of 60 or higher. Intervention Patients randomly assigned to receive flexible doses of venlafaxine ER (37.5-300 mg/d) or placebo for 24 weeks.
Main outcome measures: Primary measure was the change from baseline in the Clinician-Administered Posttraumatic Stress Disorder Scale score. Secondary measures included remission, defined as a Clinician-Administered Posttraumatic Stress Disorder Scale score of 20 or lower, and changes in symptom cluster scores, frequency of remission, and time to remission. Measures of stress vulnerability, resilience, depression, quality of life, functioning, and global illness severity were also taken.
Results: Mean changes from baseline in Clinician-Administered Posttraumatic Stress Disorder Scale total scores at end point were -51.7 for venlafaxine ER and -43.9 for placebo (P = .006). Improvement was significantly greater for the venlafaxine ER group than for the placebo group in cluster scores for reexperiencing (P = .008) and avoidance/numbing (P = .006), but not for hyperarousal. Remission rates were 50.9% for venlafaxine ER and 37.5% for placebo (P = .01). The venlafaxine ER group also showed significantly greater improvement at end point than the placebo group (P<.05) on all other reported outcome measures. The mean maximum daily dose of venlafaxine ER was 221.5 mg/d. Withdrawal rates were similar between groups with no significant difference in dropouts attributable to adverse events.
Conclusion: In this study, venlafaxine ER was effective and well tolerated in short-term and continuation treatment of patients with posttraumatic stress disorder.