Viibryd, the brand name for vilazodone, is an antidepressant medication used to treat major depressive disorder (MDD) in adults [1.3.4]. It has a unique mechanism of action, functioning as both a selective serotonin reuptake inhibitor (SSRI) and a partial agonist of the 5-HT1A serotonin receptor [1.9.2]. This dual action helps to increase serotonin levels in the brain, which is thought to regulate mood [1.9.4]. While effective, Viibryd's metabolism and effects on serotonin mean that it can interact negatively with many other substances. It's essential to disclose all medications, supplements, and alcohol use to your healthcare provider to prevent dangerous outcomes.
Absolute Contraindication: Monoamine Oxidase Inhibitors (MAOIs)
The most critical warning for Viibryd is its interaction with Monoamine Oxidase Inhibitors (MAOIs). MAOIs are a class of antidepressants that are contraindicated with Viibryd due to a high risk of causing serotonin syndrome, a potentially life-threatening condition [1.4.3, 1.4.4].
Symptoms of serotonin syndrome can include [1.4.4, 1.3.5]:
- Agitation, confusion, or hallucinations
- Rapid heart rate and high blood pressure
- Muscle rigidity or twitching
- Fever and excessive sweating
- Nausea, vomiting, and diarrhea
A mandatory "washout" period is required when switching between these medications. You must wait at least 14 days after stopping an MAOI before starting Viibryd, and at least 14 days after stopping Viibryd before starting an MAOI [1.4.1, 1.4.3]. Examples of MAOIs include phenelzine (Nardil), tranylcypromine (Parnate), isocarboxazid (Marplan), selegiline (Emsam), and the antibiotic linezolid [1.4.3].
High-Risk Interactions: Other Serotonergic Drugs
Beyond MAOIs, many other substances can increase serotonin levels. Combining them with Viibryd raises the risk of serotonin syndrome [1.5.1, 1.5.2]. While your doctor may sometimes prescribe these combinations with careful monitoring, you should never mix them without explicit medical guidance.
These include:
- Other Antidepressants: SSRIs like sertraline (Zoloft), SNRIs like duloxetine (Cymbalta), and tricyclic antidepressants (TCAs) like amitriptyline all increase serotonin [1.2.1, 1.5.2].
- Triptans: These migraine medications, such as sumatriptan (Imitrex), are serotonergic agents [1.2.3, 1.5.5].
- Certain Pain Medications: Opioids like tramadol and fentanyl can increase serotonin levels [1.5.1].
- Herbal Supplements: St. John's Wort is a well-known supplement used for depression that significantly increases the risk of serotonin syndrome when mixed with drugs like Viibryd [1.2.1, 1.4.3].
- Others: Buspirone (an anti-anxiety medication), lithium, and tryptophan supplements also carry this risk [1.2.5, 1.5.1].
Medications That Increase Bleeding Risk
Viibryd can interfere with the function of platelets, which are blood cells responsible for clotting [1.2.3]. This effect increases the risk of bleeding events, from minor issues like nosebleeds to serious gastrointestinal bleeding [1.6.3, 1.6.4]. This risk is amplified when Viibryd is taken with other medications that also affect bleeding.
Key medications to be cautious with include:
- NSAIDs (Nonsteroidal Anti-Inflammatory Drugs): Common over-the-counter pain relievers like ibuprofen (Advil, Motrin) and naproxen (Aleve) increase bleeding risk [1.2.1, 1.6.1]. For occasional pain relief, acetaminophen (Tylenol) is often considered a safer alternative as it does not carry the same risk [1.2.1].
- Anticoagulants (Blood Thinners): Drugs like warfarin (Coumadin), apixaban (Eliquis), and rivaroxaban (Xarelto) are designed to prevent clots and their effect is heightened by Viibryd [1.2.1, 1.6.3].
- Antiplatelet Drugs: Medications such as aspirin and clopidogrel (Plavix) also increase this risk [1.2.1].
Understanding CYP3A4 Enzyme Interactions
Viibryd is primarily metabolized by a liver enzyme called CYP3A4 [1.8.1, 1.8.2]. Other drugs can either inhibit or induce this enzyme, which dangerously alters the concentration of Viibryd in the body.
- CYP3A4 Inhibitors: These drugs block the enzyme, causing Viibryd levels to rise, which increases the risk of side effects.
- CYP3A4 Inducers: These drugs boost the enzyme's activity, causing Viibryd to be cleared from the body too quickly, making it less effective [1.8.1].
Your doctor may need to adjust your Viibryd dosage if you take one of these medications [1.3.2, 1.8.3].
Comparison of CYP3A4 Interacting Drugs
| Drug Type | Effect on Viibryd | Examples | Potential Action Required |
|---|---|---|---|
| Strong CYP3A4 Inhibitors | Increases Viibryd levels and risk of side effects | Ketoconazole, itraconazole, clarithromycin [1.2.4, 1.8.3] | Reduce Viibryd dose (e.g., not to exceed 20mg/day) [1.3.2, 1.4.1] |
| Strong CYP3A4 Inducers | Decreases Viibryd levels, reducing effectiveness | Rifampin, carbamazepine, St. John's Wort [1.2.1, 1.2.3, 1.8.1] | Consider increasing Viibryd dosage [1.3.2] |
Other Important Substances to Avoid
Alcohol
It is strongly recommended to avoid alcohol while taking Viibryd [1.7.2, 1.7.4]. Alcohol can worsen the central nervous system side effects of Viibryd, such as dizziness, drowsiness, and impaired judgment [1.7.1, 1.7.2]. Furthermore, alcohol can worsen the symptoms of depression, potentially counteracting the medication's benefits [1.7.2].
Grapefruit and Grapefruit Juice
Grapefruit products can act as a CYP3A4 inhibitor, increasing Viibryd levels in the body and heightening the risk of side effects [1.2.1]. It is best to avoid consuming grapefruit while on this medication [1.2.1].
Conclusion: Always Consult Your Doctor
Managing treatment with Viibryd requires open and honest communication with your healthcare provider. Because of the extensive list of potential interactions—ranging from prescription medications and over-the-counter pain relievers to herbal supplements and alcohol—it is critical to never start or stop any new substance without first consulting your doctor or pharmacist [1.3.3]. Proactive management ensures that Viibryd can work safely and effectively to treat major depressive disorder. For more detailed information, you can consult the official FDA label for the medication.
