Vilazodone, sold under the brand name Viibryd among others, is a medication used to treat major depressive disorder.[1] While it was being studied for generalized anxiety disorder such research had stopped as of 2017.[3] It is taken by mouth.[1]
Common side effects include nausea, diarrhea, and trouble sleeping.[1] Serious side effects may include suicide in those under the age of 25, serotonin syndrome, bleeding, mania, and SIADH.[1] A withdrawal syndrome may occur if the dose is rapidly decreased.[1] Use during pregnancy and breastfeeding is not generally recommended.[4] 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.[1]
Vilazodone was approved for medical use in the United States in 2011.[1] It is not approved in other countries as of 2016.[5] In the United States the wholesale cost for a month of medication is about 261 USD.[6] In 2016 it was the 278th most prescribed medication in the United States with more than a million prescriptions.[7]
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.[8]
According to FDA staff, "it is unknown whether [vilazodone] has any advantages compared to other drugs in the antidepressant class."[9]
Development for generalized anxiety disorder has been stopped as of 2017.[3]
Adverse effects
On September 6, 2016, the FDA wrote a letter to Forest Labs about Viibryd. New warnings will be added to the Viibryd label related to a link between the drug and acute pancreatitis.[10] Acute pancreatitis can lead to serious injury and even death. Pancreatitis, especially if it reoccurs, can lead to pancreatic cancer, which is almost always fatal.
Additionally, it is expected that new warnings related to sleep paralysis will also be added to the Viibryd label and prescribing information. Sleep paralysis is a condition in which a person is awake but cannot move or speak. Generally, sleep paralysis occurs upon waking and lasts less than one minute. Although sleep paralysis is a serious condition, and can cause psychological harm in the most severe cases, the condition is generally not life threatening.
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.[8] Whereas in randomized controlled trials these rates were 28%, 23.4% and 13.3%, respectively.[8] 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.[11] Incidence of adverse effects include:[2]
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 (male persons only)
§ Delayed ejaculations (male persons only)
§ Erectile dysfunction (male persons 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.[12]
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.[12][13][14]
§ Seizures
§ Syndrome of inappropriate antidiuretic hormone secretion (SIADH)—a condition characterised by an abnormally excessive secretion of antidiuretic hormone causing potentially-fatal electrolyte abnormalities (such as hyponatraemia).
§ Hyponatraemia (a complication of the former)—low blood sodium.
