NEW YORK (Reuters Health) – Vilazodone, the first of a new class of antidepressants known as indolalkylamines, has been shown in a phase III trial to be effective and well tolerated for the treatment of major depressive disorder, with a rapid onset of effect.

The researchers explain in the March issue of the Journal of Clinical Psychiatry that vilazodone “combines properties of a selective serotonin reuptake inhibitor with 5-hydroxytryptamine-1A partial agonist activity.” They add that in addition to offering a rapid antidepressant effect, this agent likely has “a lower risk of sexual dysfunction” than currently available therapies.

Dr. Karl Rickels at the University of Pennsylvania in Philadelphia and colleagues report on their intention-to-treat analysis of a randomized trial in which 410 adults with major depressive disorder received either vilazodone or placebo for 8 weeks. Vilazodone was titrated from 10 mg to 40 mg once a day over the course of two weeks.

Compared to the placebo group, after 8 weeks the vilazodone group had greater mean improvements from baseline on the Montgomery-Asberg Depression Rating Scale (MADRS; p = 0.001) and the 17-item Hamilton Rating Scale for Depression (HAM-D-17; p = 0.022).

In fact, the researchers note, the treatment group was already demonstrating significant improvements on both scales after just one week.

The vilazodone-treated subjects also had significantly higher response rates on the MADRS (p = 0.007), the HAM-D-17 (p = 0.011), and the Clinical Global Impressions-Improvement scale (p = 0.001).

Most treatment-related side effects were mild or moderate, according to the article. Five patients in each group experienced a major adverse event.

“Vilazodone is effective for the treatment of major depressive disorder in adults, with symptom relief starting at 1 week, and is well tolerated at a dose of 40 mg/day,” the investigator conclude.

Reference:
J Clin Psychiatry 2009;70:326-333.