In January 2011, the FDA approved Viibryd (vilazodone) to treat major depressive disorder. Viibryd offers a new choice for doctors treating adults with depression. Viibryd works in a novel manner, affecting serotonin in 2 ways. It is a potent and selective serotonin reuptake inhibitor (SSRI) and a partial agonist of the 5-hydroxytryptamine 1a (5-HT1A) receptor. Serotonin helps regulate mood and other processes.
The most common side effects reported with Viibryd included diarrhea, nausea, vomiting, and insomnia. In clinical studies, Viibryd was not associated with significant weight gain or reduced sexual function. Decreased libido was reported in 4% of patients taking Viibryd compared to < 1% of those on placebo. Erectile dysfunction was reported by 2% of patients treated with Viibryd compared to 1% with placebo. It is speculated that Viibryd may result in fewer sexual side effects than other antidepressants. Weight gain and sexual side effects are among the top complaints with antidepressants, especially the SSRIs.
The Bottom Line
- Viibryd’s mechanism of action (how it works) is novel. The drug combines the mechanism of SSRIs like Prozac and Lexapro with the mechanism of the anxiety drug Buspar, which targets the brain receptor 5-HT1A.
- Viibryd is FDA-approved, meaning it has been proven to be effective and safe in clinical studies.
- More data are needed to support claims of reduced weight gain and sexual function. Each of the 2 pivotal studies was only 8 weeks in length. And in the world of depression, treatment typically lasts years for patients. Secondly, no head-to-head studies against other antidepressants have been done. So until the results of long-term and head-to-head-studies are available, no claims of superiority can be made.
Viibryd will be available in the second quarter of the year in the following dosage strengths: 10, 20, and 40 milligram tablets.
