Vilazodone (Viibryd) is an atypical antidepressant released in 2011. It was described as the first serotonin partial agonist/reuptake inhibitor (SPARI). Alternately, it can be grouped with vortioxetine (Trintellix, 2013) as a serotonin modulator and stimulator (SMS). Vilazodone is less complicated than vortioxetine in terms of mechanism of action.
“Virile” Viibryd was marketed as having fewer sexual side effects than SSRIs, though it does cause slightly more sexual dysfunction than placebo.
Viibryd’s mechanism is a “Hybrid” an SSRI and a 5-HT1A partial agonist. In other words, vilazodone combines the pharmacologic actions of an SSRI and the anxiolytic buspirone (Buspar). SSRIs are famously detrimental to sexual functioning. Buspirone improves sexually functioning. To concoct a “Poor Man’s Viibryd”, prescribe buspirone with the purest SSRI, escitalopram (Lexapro).
Until it goes generic, Viibryd is $300/month, and is unproven to be superior to an SSRI for treatment of depression.
Vilazodone needs to be taken with food for adequate absorption. Only 50% of the dose is absorbed on an empty stomach.
At 40 mg/day, the most common adverse effects are diarrhea (28% vs 9% placebo), nausea (23% vs 5% placebo), and insomnia (6% vs 2% placebo).
Dosing: Target dose is 20–40 mg QD with food. Must titrate with 10 mg QD for the first week, as shown below. The 30-day starter pack contains 10 mg tab x 7 and 20 mg tab x 23. To discontinue, taper off over about a week.