Vilazodone, sold under the brand name Viibryd among others, is a medication used to treat major depressive disorder. It is classified as a serotonin modulator and 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, pancreatitis, and SIADH. Vilazodone may cause less emotional blunting than typical SSRIs and SNRIs. 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 2019, it was the 334th most commonly prescribed medication in the United States, with more than 900thousand prescriptions. The drug lost patent protection in June 2022 for adults, and is scheduled to lose exclusivity for pediatrics in July 2023. Generic versions have been approved by the U.S. Food and Drug Administration (FDA).
Medical uses
Seven controlled efficacy trials were conducted of vilazodone for treatment of major depressive disorder (MDD). Five of these trials showed no significant influence of vilazodone over placebo on depressive symptoms. In the remaining two trials, small but significant advantages of vilazodone over placebo were found. According to these 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 in 2011, "it is unknown whether vilazodone has any advantages compared to other drugs in the antidepressant class." A 2019 review stated that "present studies do not suggest the superiority of vilazodone compared with other antidepressants."
Development of vilazodone for generalized anxiety disorder (GAD) 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 warning to be added to the label related to a link between the drug and acute pancreatitis and sleep paralysis.
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 (35.7%), nausea (31.6%), and headache (20.0%); 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. Additionally, vilazodone may cause less emotional blunting than typical SSRIs and SNRIs. Incidence of adverse effects include:
Very common adverse effects (incidence >10%) Nausea Diarrhea Headache
Common adverse effects (1–10% incidence)
Vomiting
Dry mouth
Dizziness
Insomnia
Uncommon adverse effects (0.1–1% incidence)
Somnolence
Paraesthesia
Tremor
Abnormal dreams
Libido decreased
Restlessness
Akathisia
Restless legs syndrome
Abnormal orgasms (men only) Delayed ejaculations (men only) Erectile dysfunction (men only) Fatigue Feeling jittery Palpitations Ventricular premature contractions Arthralgia Increased appetite
Rare adverse effects (<0.1% incidence) Serotonin syndrome—a serious adverse effect characterised by: Nausea Vomiting Mental status change (e.g. confusion, hallucinations, agitation, coma, stupor) Muscle rigidity Tremor Myoclonus Hyperreflexia—overresponsive/overactive reflexes Hyperthermia—elevated body temperature Autonomic instability (e.g. tachycardia, dizziness, abnormally excessive sweating, etc.) 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.