Vilazodone (Viibryd)

Pharmacokinetics of Vilazodone

Absorption Take with food! Taking on an empty stomach can result in 50% lower plasma concentrations (and thus and treatment failure)

Vilazodone: Cytochrome P450 Metabolism

Substrate of (Metabolized by) 3A4
  • Similar to vortioxetine, vilazodone acts like an SSRI but also has direct serotonin receptor interactions that is thought to theoretically add to its clinical benefit. It has the following actions:
  • Serotonin (5-HT) transporter (SERT) inhibition
    • Which is the primary mechanism of action of classic antidepressants like SSRIs and SNRIs.
  • Serotonin (5-HT) receptor partial agonism
    • 5-HT1A, which should theoretically leads to enhanced downregulation of presynaptic 5-HT1A receptors and more a robust disinhibition of serotonin release (but this is not clinically proven!), and may make it an anxiolytic as well as antidepressant in action.
  • Serotonin (5-HT) receptor agonism
    • 5-HT4 agonism, which causes diarrhea and is a common side effect of vilazodone.
      • This is why 5-HT4 agonists (e.g. - cisapride, prucalopride) are used in the treatment of constipation
  • Vilazodone is relatively non-toxic in overdose

Dosing for Vilazodone

  • Vilazodone comes in
  • The most recent data suggests there is good tolerability related to weight and sexual side effects as well as anxiety benefits.
  • Vilazodone has pro-kinetic effects, which can cause diarrhea