Vilazodone, sold under the brand nameViibryd among others, is a medication used to treat major depressive disorder. While it was being studied for generalized anxiety disorder, such research had stopped as of 2017. It is taken by mouth. Common side effects include nausea, diarrhea, and trouble sleeping. Serious side effects may include increased suicidal thoughts or actions in those under the age of 25, serotonin syndrome, bleeding, mania, and SIADH. A withdrawal syndrome may occur if the dose is rapidly decreased. Use during pregnancy and breastfeeding is not generally recommended. It is in the serotonin modulator class of medications and is believed to work both as an SSRI and activator of the 5-HT1A receptor. Vilazodone was approved for medical use in the United States in 2011 and in Canada in 2018. In the United States the wholesale cost for a month of medication is about 261 USD. In 2017, it was the 285th most commonly prescribed medication in the United States, with more than one million prescriptions.
Medical uses
According to two eight-week trials in adults, vilazodone has an antidepressant response after one week of treatment. After eight weeks it resulted in a 13% greater response than placebo. Remission rates, however, were not significantly different versus placebo. According to FDA staff, "it is unknown whether vilazodone has any advantages compared to other drugs in the antidepressant class." Development for generalized anxiety disorder has been stopped as of 2017. While there is tentative evidence of a small benefit in GAD there is a high rate of side effects.
Adverse effects
On September 6, 2016, the FDA wrote a letter to Forest Labs requiring a new warnings to be added to the label related to a link between the drug and acute pancreatitis. After a one-year, open-label study assessing the safety and tolerability of vilazodone in people with major depressive disorder, the most common adverse effects were diarrhea, nausea, and headache ; greater than 90% of these adverse effects were mild or moderate. In randomized controlled trials, meanwhile, these rates were 28%, 23.4% and 13.3%, respectively. In contrast to other SSRIs, initial trials showed that vilazodone did not cause decreased sexual desire/function, which often cause people to abandon their use. Incidence of adverse effects include: ;Very common adverse effects :
Mania/hypomania—a potentially dangerously elated/agitated mood. Every antidepressant has the potential to induce these psychiatric reactions. They are particularly problematic in those with a history of hypomania/mania such as those with bipolar disorder.
;Unknown-incidence adverse effects:
Suicidal ideation—all antidepressants can cause suicidal ideation especially in young adults and adolescents under the age of 25.
Abnormal bleeding—the SSRIs are known for their ability to increase the incidence of gastrointestinal bleeds and other bleeding abnormalities.
Antidepressant exposure is associated with shorter average duration of pregnancy, increased risk of preterm delivery, lower birth weight, and lower Apgar scores. It is uncertain whether there is an increased rate of septal heart defects among children whose mothers were prescribed an SSRI in early pregnancy.
Pharmacology
Vilazodone acts as a serotonin reuptake inhibitor and 5-HT1A receptor partial agonist. It has negligible affinity for other serotonin receptors such as 5-HT1D, 5-HT2A, and 5-HT2C. It also exhibits clinically unimportant inhibitory activity at the norepinephrine and dopamine transporters. Vilazodone is best absorbed with food and has a bioavailability of 72% under fed conditions. The Cmax increased between 147%-160% and the AUC increased between 64%-85% of vilazodone when it was administered with either a fatty or light meal.
