Viibryd (Vilazodone) Dosing for Major Depressive Disorder
Start vilazodone at 10 mg once daily with food for 7 days, then increase to 20 mg once daily for 7 days, with a target dose of 40 mg once daily taken with food. 1
Initial Titration Schedule
The FDA-approved dosing requires gradual titration to minimize gastrointestinal side effects 1, 2:
- Days 1-7: 10 mg once daily with food
- Days 8-14: 20 mg once daily with food
- Day 15 onward: 20-40 mg once daily with food (target dose 40 mg)
Food requirement is critical - vilazodone must be taken with food to ensure adequate plasma concentrations and therapeutic efficacy 1, 2. Without food, absorption is significantly reduced.
Target Therapeutic Dose
The recommended target dosage is 20-40 mg once daily, with 40 mg/day demonstrating superior efficacy in clinical trials 1, 3. The 40 mg dose showed significant improvement in Montgomery-Åsberg Depression Rating Scale (MADRS) scores compared to placebo, with benefits emerging as early as week 1-2 in some studies 3.
Dose Adjustments for Drug Interactions
With strong CYP3A4 inhibitors (itraconazole, clarithromycin, voriconazole): Reduce vilazodone to maximum 20 mg once daily during concomitant use; resume original dose when inhibitor is discontinued 1.
With strong CYP3A4 inducers (carbamazepine, phenytoin, rifampin): Consider increasing vilazodone dose by 2-fold up to maximum 80 mg once daily over 1-2 weeks if inducer used >14 days; taper back to original dose over 1-2 weeks when inducer is discontinued 1.
Treatment Duration and Monitoring
- Initial assessment: Evaluate therapeutic response, adverse effects, and suicidal ideation within 1-2 weeks of starting treatment 4, 5
- Response evaluation: Modify treatment if inadequate response after 6-8 weeks 4, 5
- First episode MDD: Continue treatment for 4-9 months after satisfactory response 4, 5
- Recurrent MDD (≥2 episodes): Consider years to lifelong therapy 4, 5
Monitor closely for suicidal thoughts during the first 1-2 months when risk is highest 4, 5.
Discontinuation Protocol
Taper gradually rather than stopping abruptly 1:
- From 40 mg: Reduce to 20 mg daily for 4 days, then 10 mg daily for 3 days
- From 20 mg: Reduce to 10 mg daily for 7 days
Common Pitfalls to Avoid
Do not skip the titration schedule - the 2-week titration is necessary because gastrointestinal side effects (diarrhea 28%, nausea 23%) are dose-dependent and most common during initial treatment 6, 7. Most GI symptoms resolve within one week 7.
Do not administer without food - this is a critical requirement that distinguishes vilazodone from many other antidepressants 1, 2.
Do not combine with MAOIs - allow at least 14 days between discontinuing an MAOI and starting vilazodone, and vice versa 1.
Tolerability Profile
Vilazodone demonstrates favorable tolerability compared to traditional SSRIs, with sexual dysfunction rates similar to placebo 6, 7, minimal weight gain 6, and no clinically significant effects on vital signs or ECG parameters 6. Discontinuation rates due to adverse events were 7.1% in 8-week trials and 20.7% in 52-week trials 6.