Viibryd (Vilazodone): A Guide to Its Use for Depression and Anxiety
Viibryd (vilazodone), an FDA-approved medication for treating major depressive disorder (MDD) in adults, is known for its faster onset of action and more favorable side effect profile compared to most other antidepressants.
Viibryd must be taken with food or 50% of the medication will not be absorbed. This handout provides an overview of Viibryd, including its benefits, dosing guidelines, potential side effects, contraindications, and off-label uses supported by research.
Mechanism and Rate of Action
Viibryd stands out in the realm of antidepressants due to its dual mechanism of action, functioning both as a serotonin reuptake inhibitor and a 5HT1A partial agonist. This unique combination is believed to contribute to its rapid efficacy in alleviating symptoms of depression, with patients potentially experiencing benefits within just 1 to 2 weeks, a significant improvement over the typical 4 weeks or more required for traditional antidepressants to take effect.
The serotonin 1A partial agonist property, a relatively unique mechanism found in antidepressants like vilazodone, vortioxetine, and certain atypical antipsychotics such as quetiapine and aripiprazole, heralds the advent of SPARIs, or serotonin partial agonist reuptake inhibitors. This mechanism is linked to a lower incidence of sexual dysfunction and weight gain, side effects commonly associated with many antidepressants.
The drug has a mean terminal half-life of 25 hours and is metabolized by the CYP450 3A4 enzyme.
It's also noteworthy that its absorption and bioavailability are significantly impacted by food intake, being reduced by approximately 50% when taken on an empty stomach.
Benefits for Depression and Anxiety
Major Depressive Disorder (MDD)
Viibryd has demonstrated efficacy in alleviating symptoms of major depressive disorder (MDD) in clinical trials, where patients reported significant improvements in their depression symptoms. These improvements were quantified using the Montgomery-Asberg Depression Rating Scale (MADRS), with Viibryd users showing a decrease in scores by 2.5 to 5.1 points compared to those on a placebo.
Off-label Use in Anxiety and OCD
While not officially approved by the FDA for these conditions, Viibryd has shown promise in the off-label treatment of generalized anxiety disorder (GAD) and obsessive-compulsive disorder (OCD). Studies suggest that Viibryd can aid in reducing the symptoms associated with GAD and OCD, offering potential relief for patients struggling with these disorders.
Expanding Treatment Horizons
Beyond its primary use in treating MDD, Viibryd is also explored off-label for a broader spectrum of conditions, including social anxiety, panic disorders, as well as depression in geriatric and adolescent populations. This expanded application underscores Viibryd's potential versatility in addressing a range of mental health challenges.
Dosing Guidelines
Viibryd should be taken once daily with food to enhance absorption. It is available in 10 mg, 20 mg, and 40 mg tablets. The usual starting dose is 10 mg once daily for 7 days, increased to 20 mg once daily. After 1-2 weeks on 20mg, if symptoms are not fully treated, many increase to 40mg daily.
Higher doses of these medications might enhance serotonin levels in the brain more effectively, potentially increasing efficacy for some patients while reducing tolerability for others, with doses of 50–80 mg daily being considered for those with treatment-resistant depression or OCD. Additionally, a lack of response in elderly patients may prompt an evaluation for conditions like mild cognitive impairment or Alzheimer's disease.
Best Time to Take
It is recommended to take Viibryd at the same time each day to maintain an even level of the medication in your body.
Taking it with food is essential to maximize its absorption.
Potential Side Effects
Common side effects of Viibryd include:
Diarrhea
Nausea
Vomiting
Insomnia
Serious side effects can include:
Serotonin syndrome: Symptoms include hallucinations, confusion, racing heartbeat, and changes in blood pressure. This occurs when taken with other medications or supplements that increase serotonin. Please read Dr. Danish’s blog on serotonin syndrome, here.
Discontinuation syndrome: Symptoms include flu-like symptoms, anxiety, insomnia, and mood changes if the medication is stopped abruptly.
Increased risk of suicidal thoughts and behaviors in people 24 years of age and younger.
Potential Contraindications
Do not take Viibryd if you:
Are taking or have taken a monoamine oxidase inhibitor (MAOI) within 14 days, as this may lead to serotonin syndrome.
Are being treated with the antibiotic linezolid or intravenous methylene blue.
Stopping the Medication
Gradually tapering off the medication is advisable to circumvent possible withdrawal reactions.
A common strategy that many patients find tolerable involves reducing the dose by 50% for three days, followed by another 50% reduction for an additional three days, before completely stopping the medication.
Should withdrawal symptoms appear during the process of discontinuation, it's recommended to increase the dose temporarily to alleviate the symptoms before attempting to withdraw again, this time at a much slower pace.
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