VIIBRYD
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VIIBRYD (VIIBRYD).
Vilazodone is a selective serotonin reuptake inhibitor (SSRI) and a partial agonist at serotonin 5-HT1A receptors. It increases serotonin levels in the synaptic cleft by inhibiting its reuptake, and the 5-HT1A partial agonism may enhance serotonergic transmission and reduce side effects like sexual dysfunction.
| Metabolism | Primarily metabolized via CYP3A4 and to a lesser extent via CYP2C19 and other enzymes. |
| Excretion | Approximately 95% of the dose is excreted in feces (as unchanged drug and metabolites) and <1% in urine as unchanged drug. Renal elimination accounts for <3% of the dose as the active metabolite. |
| Half-life | Terminal elimination half-life of vilazodone is approximately 25 hours (range 22-30 hours). Steady state is achieved within 3-4 days. The half-life supports once-daily dosing. |
| Protein binding | Approximately 96-99% bound to serum albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Volume of distribution is approximately 293 L (≈ 4.2 L/kg for a 70 kg individual), indicating extensive extravascular distribution. |
| Bioavailability | Absolute bioavailability of oral vilazodone is approximately 72% (range 60-80%) when taken with food. Food enhances absorption (Cmax increased by up to 147%, AUC by 64%) compared to fasting conditions. |
| Onset of Action | Oral: Clinical improvement (antidepressant effect) may be observed as early as 1-2 weeks, but full therapeutic benefit typically requires 4-8 weeks. No parenteral route is available. |
| Duration of Action | Duration of action for a single oral dose is approximately 24 hours, consistent with once-daily dosing. Steady-state concentrations are maintained with daily administration. |
10 mg orally once daily for 7 days, then 20 mg once daily for 7 days, then 40 mg once daily; target dose 40 mg once daily. Maximum dose 40 mg once daily.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (CrCl 30-89 mL/min). For severe renal impairment (CrCl 15-29 mL/min): maximum dose 20 mg once daily. Not recommended for end-stage renal disease (CrCl <15 mL/min). |
| Liver impairment | Mild to moderate hepatic impairment (Child-Pugh A or B): maximum dose 20 mg once daily. Severe hepatic impairment (Child-Pugh C): not recommended. |
| Pediatric use | Not approved for pediatric use; safety and efficacy not established. |
| Geriatric use | No specific dose adjustment recommended; clinical studies included patients aged >65 years. Use with caution due to potential increased sensitivity; maximum dose 40 mg once daily. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for VIIBRYD (VIIBRYD).
| Breastfeeding | Unknown if excreted in human milk. There are no adequate studies in nursing women. M/P ratio not available. Breastfeeding is not recommended due to potential for serious adverse reactions in nursing infants (e.g., irritability, feeding problems, weight loss, insomnia). |
| Teratogenic Risk | Pregnancy Category C. No adequate studies in pregnant women. In animal studies, vilazodone caused decreased fetal body weight and delayed ossification at doses ≥2 times the MRHD. First trimester: insufficient data to assess risk of major malformations. Second and third trimesters: neonatal adaptation syndrome including respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability, and constant crying may occur following late third trimester exposure due to serotonergic effects. |
■ FDA Black Box Warning
Antidepressants increased the risk of suicidal thinking and behavior in children, adolescents, and young adults in short-term studies. Monitor for worsening and emergence of suicidal thoughts and behaviors.
| Serious Effects |
["Concomitant use of MAOIs (within 14 days) due to risk of serotonin syndrome","Concomitant use of linezolid or intravenous methylene blue"]
| Precautions | ["Suicidal thoughts and behaviors in pediatric and young adult patients","Serotonin syndrome or neuroleptic malignant syndrome-like reactions","Activation of mania/hypomania in bipolar disorder patients","Seizures (discontinue if seizures occur)","Abnormal bleeding (especially with NSAIDs, aspirin, or anticoagulants)","Angle-closure glaucoma (myadriasis risk)","SIADH and hyponatremia in elderly or volume-depleted","Sexual dysfunction","Discontinuation syndrome upon abrupt withdrawal"] |
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| Fetal Monitoring | Monitor for neonatal adaptation syndrome in infants exposed during third trimester; assess for signs of respiratory distress, feeding difficulties, and autonomic instability. In mother, monitor for signs of serotonin syndrome, especially if co-administered with other serotonergic drugs. Assess for mood changes and suicidality during pregnancy and postpartum. |
| Fertility Effects | Animal studies: at doses up to 2 times MRHD, no impairment of male or female fertility observed. Human data: insufficient. Theoretical risk of hyperprolactinemia and sexual dysfunction with SSRIs may affect fertility. |