KRB asked
Is it safe that my doc started me on 20mg Viibryd? I’ve read most start the titrate at 10mg.
At a glance
- The recommended starting dose of Viibryd per the manufacturer is 10mg per day, which would then be increased to a target dose of 20 to 40mg. However, higher starting doses have been used safely in clinical studies.
Answer
You are correct that Viibryd is commonly recommended to be started at the lowest dose, which is 10mg, and slowly titrated up to a target dose of 20 to 40mg.
The FDA-approved prescribing information for Viibryd recommends the following dosing:
"The recommended dose for VIIBRYD is 40 mg once daily. VIIBRYD should be titrated, starting with an initial dose of 10 mg once daily for 7 days, followed by 20 mg once daily for an additional 7 days, and then an increase to 40 mg once daily."
It is important to note that even though 10mg of Viibryd is generally the recommended starting dose, there certainly could be situations where your doctor (and you) may feel a different starting dose is more appropriate.
For example, if you have previously been on other antidepressants, and tolerated them well in terms of side effects, starting at a higher dose of Viibryd may be something worth trying as you will reach your target dose more quickly.
Nevertheless, if you are concerned about the dose of Viibryd you have been prescribed, be sure to discuss it with your doctor.
Viibryd Initial Dosing
Like most antidepressants, Viibryd is recommended to be started at a dose lower than the intended target (i.e. final) dose to reduce both the risk and severity of side effects.
Side effects from antidepressants are a major reason for treatment failure, and the side effects tend to be most severe when they are first initiated.
The side effect profile will vary by drug, but when it comes to Viibryd, the following are the most commonly reported:
- Gastrointestinal (diarrhea, nausea, vomiting)
- Dizziness
- Sedation
- Insomnia
- Weight gain
- Dry mouth
- Restlessness
- Headache and related flu-like symptoms
Most studies that have evaluated Viibryd state that the side effects are dose-dependent, meaning their incidence increases with higher doses.
However, they tend to decrease (or even go away altogether) over time. Therefore, starting at a low dose of Viibryd and working your way up is generally the method that will produce the least number of side effects.
To reiterate, to lessen the risk of side effects, the prescribing information for Viibryd recommends the following dosing schedule when starting:
- 10 mg by mouth once daily with food for 7 days.
- 20 mg once daily with food for 7 days.
- The dose may be increased up to 40 mg once daily if needed.
Other Initial Dose Strategies
There have been several studies that have tried different dosing strategies for Viibryd from the recommended starting dose of 10 mg per day.
One large study, published in The Primary Care Companion for CNS Disorders, evaluated three different starting doses (10mg, 20mg, and 40mg) and found all were similarly tolerated. In fact, the only statistically significant difference they found in side effects among the 3 different strengths was that the 40mg group experienced a higher incidence of diarrhea. The study concluded:
"There were no meaningful differences in efficacy or tolerability between the 3 different dose-initiation strategies with vilazodone; however, diarrhea appeared to be more frequently reported with the 40-mg/d dose."
So, the fact that your doctor recommends starting at 20mg may be based on their research or experience with the drug, or your previous experience with antidepressants. As mentioned, if you are concerned about any aspect of your therapy, be sure to discuss it with them.
References
- Elsevier ClinicalKey: Viibryd Monograph (Accessed 2/24/19)
- Viibryd Prescribing Information
- An 8-Week Randomized, Double-Blind Trial Comparing Efficacy, Safety, and Tolerability of 3 Vilazodone Dose-Initiation Strategies Following Switch From SSRIs and SNRIs in Major Depressive Disorder. PubMed
- Double-blind switch study of vilazodone in the treatment of major depressive disorder. PubMed