Vilazodone (Viibryd) Dosing Recommendations
The recommended dosing for Viibryd (vilazodone) is to start with 10 mg once daily with food for 7 days, then increase to 20 mg once daily with food, with the option to increase to 40 mg once daily with food after a minimum of 7 days between dosage increases. 1
Initial Dosing and Titration Schedule
- Starting dose: 10 mg once daily with food for 7 days
- Week 2: Increase to 20 mg once daily with food
- Week 3 or later: May increase to 40 mg once daily with food (if needed)
- Target therapeutic dose range: 20-40 mg once daily 1
Administration Requirements
- Must be taken with food to ensure adequate plasma concentrations 1, 2
- If a dose is missed, it should be taken as soon as remembered, unless it's almost time for the next dose
- Do not take two doses at the same time 1
Special Dosing Considerations
Drug Interactions
When used with strong CYP3A4 inhibitors (e.g., itraconazole, clarithromycin, voriconazole):
- Dose should not exceed 20 mg once daily 1
- Original dose can be resumed when the inhibitor is discontinued
When used with strong CYP3A4 inducers (e.g., carbamazepine, phenytoin, rifampin):
- Consider increasing dosage by 2-fold, up to maximum 80 mg once daily, over 1-2 weeks
- Gradually reduce back to original dose over 1-2 weeks when inducer is discontinued 1
Discontinuation Protocol
To minimize discontinuation symptoms, taper gradually rather than stopping abruptly:
- From 40 mg: Reduce to 20 mg once daily for 4 days, then 10 mg once daily for 3 days
- From 20 mg: Reduce to 10 mg once daily for 7 days 1
Efficacy Timeline
- Initial improvement in depressive symptoms may be observed as early as 1-2 weeks 3, 4
- Full therapeutic effect typically observed at 4-6 weeks of therapy 3
- In clinical trials, significant reductions in depression scores were seen from week 1, week 2, or week 6, depending on the study 5
Common Side Effects
Other reported effects include:
- Dizziness
- Dry mouth
- Fatigue
- Decreased libido 3
Clinical Advantages
Vilazodone has a unique mechanism as both a selective serotonin reuptake inhibitor and a 5-HT1A receptor partial agonist, which may offer:
- Potentially faster onset of action compared to some other antidepressants
- Limited adverse effects on sexual function
- Minimal effect on body weight 5, 3
Important Monitoring Considerations
- Screen for bipolar disorder before initiating treatment 1
- Monitor for emergence of suicidal thoughts and behaviors, particularly in young adults 1
- Allow at least 14 days between discontinuing MAOIs and starting vilazodone, and vice versa 1
Vilazodone represents an effective option for treating major depressive disorder with a unique pharmacological profile that may provide advantages for certain patients, though direct comparative studies with other antidepressants are limited 4.