"Sustained-Release Venlafaxine Improves Symptoms in Posttraumatic Stress Disorder: Presented at ECNP"
By Paula Moyer
AMSTERDAM, THE NETHERLANDS -- October 31, 2005 -- Patients with posttraumatic stress disorder (PTSD) show significant improvement when treated with sustained-release venlafaxine (Effexor SR) in comparison with placebo, according to investigators who presented findings here on October 25[th at the 18th Congress of the European College of Neuropsychopharmacology (ECNP).
"The venlafaxine group showed greater improvement than the placebo group starting at the week 6 and continuing throughout the study," reported Jonathan R. Davidson, MD, professor of psychiatry at Duke University Medical Center in Durham, North Carolina, where he is the director of the Anxiety and Traumatic Stress Program
At the end of the 6-month study period, "Remission rates were significantly higher for the venlafaxine group and the median time to remission was significantly shorter," he said.
The investigators were interested in the efficacy of extended-release venlafaxine for PTSD because recent research showed that both serotonin and noradrenaline are involved in the pathophysiology of PTSD and because venlafaxine binds both serotonin and noradrenaline receptors, Dr. Davidson explained.
The researchers designed a randomized, double-blind, placebo-controlled, parallel-group trial that enrolled adult outpatients with PTSD living in the United States, the United Kingdom, South Africa, and Argentina. Patients had PTSD symptoms for at least 6 months and had scores of 60 or more on the 17-item Clinician-Administered PTSD scale (CAPS-SX17).
The investigators randomized subjects to 24 weeks of either a flexible-dose sustained-release venlafaxine ranging from 37.5 to 300 mg daily or to placebo. There were 161 patients in the treatment group and 168 patients in the placebo group.
The investigators evaluated the change in the CAPS-SX17 score from baseline at week 12 or discontinuation, frequency of remission (CAPS-SX17 score of 20 or lower), time to remission, number of symptom-free days (CAPS-SX17 scores), and change from baseline in scores for several CAPS- SX17 symptom clusters (re-experiencing, avoidance or numbing, and hyperarousal).
Patients were also assessed on the following measures:
- Stress Vulnerability Scale;
- Connor-Davidson Resilience Scale;
- 17-item Hamilton Depression Rating Scale (HAM-D-17);
- Quality of Life Enjoyment and Satisfaction Questionnaire Short Form;
- Sheehan Disability Scale;
- Clinical Global Impression-Severity of Illness; and
- Global Assessment of Functioning.
The average maximum daily dose of sustained-release venlafaxine was 221 mg. Average changes from baseline in CAPS-SX17 total scores at endpoint were a reduction of 51.7 points in the treatment group and a reduction of 43.9 points for placebo (P = .006).
Remissions occurred in 50.9% of the treatment group and 37.5% of the placebo group (P = .013). Those who experienced remission did so in a median of 87.0 days in the treatment group, compared with 130.0 days in the placebo group (P = .0165).
Throughout the study, the venlafaxine group's average improvement in CAPS-SX17 cluster scores was superior to that of the placebo group for re-experiencing and avoidance or numbing (P = .008 and P = .006, respectively). The venlafaxine group also showed significantly greater improvement at endpoint than placebo for all other secondary variables (P < .05).
There was no difference between the treatment arms regarding hyperarousal.
The most common treatment-associated adverse events were headache and nausea, and withdrawal rates were similar, 30.4% and 33.3% for treatment and placebo, respectively.
The study was funded by Wyeth Research, which manufactures Effexor.
[Presentation title: A 6-month Study of Venlafaxine XR versus Placebo in the Treatment of Posttraumatic Stress Disorder. Abstract P4.041]
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