Drug interactions
Primidone + Vilazodone
Severity: Moderate
Primidone and Vilazodone: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Primidone and its metabolite phenobarbital induce CYP3A4, which can lower vilazodone plasma concentrations. Reduced exposure may weaken antidepressant efficacy and lead to relapse of depressive symptoms.
What this interaction means in plain words
Primidone and Vilazodone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Primidone belongs to Central Nervous System; Vilazodone belongs to Central Nervous System.
Why it happens
Induction of CYP3A4 by primidone/phenobarbital increases the metabolic clearance of vilazodone.
What to do
Monitor clinical response to vilazodone and consider titrating the dose upward based on response, within the maximum labeled dose, if the inducer is used for more than about two weeks. Reduce vilazodone back to the usual dose after primidone is stopped.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Vilazodone
- Isocarboxazid + Vilazodone Contraindicated
- Methylene blue + Vilazodone Contraindicated
- Phenelzine + Vilazodone Contraindicated
- Rasagiline + Vilazodone Contraindicated
- Selegiline transdermal + Vilazodone Contraindicated
- Selegiline + Vilazodone Contraindicated
Other interactions of Primidone
- Lorlatinib + Primidone Contraindicated
- Lurasidone + Primidone Contraindicated
- Primidone + Ranolazine Contraindicated
- Primidone + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Primidone + Voriconazole Contraindicated
- Abiraterone + Primidone Major
Frequently asked questions
Can I take Primidone with Vilazodone?
MediHelp rates the interaction as moderate. Primidone and Vilazodone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Primidone and its metabolite phenobarbital induce CYP3A4, which can lower vilazodone plasma concentrations. Reduced exposure may weaken antidepressant efficacy and lead to relapse of depressive symptoms.
How serious is the interaction between Primidone and Vilazodone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor clinical response to vilazodone and consider titrating the dose upward based on response, within the maximum labeled dose, if the inducer is used for more than about two weeks. Reduce vilazodone back to the usual dose after primidone is stopped.
What other medicines interact with Vilazodone?
MediHelp also lists interactions of Vilazodone with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Vilazodone page.
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