Drug interactions
Apremilast + Phenytoin
Severity: Major
Apremilast and Phenytoin: major interaction.
Last updated Sources: UK SmPC
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
Phenytoin substantially lowers apremilast exposure, which can cause loss of therapeutic effect in psoriasis or related conditions.
What this interaction means in plain words
Apremilast and Phenytoin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Apremilast belongs to Miscellaneous; Phenytoin belongs to Central Nervous System.
Why it happens
Phenytoin induces CYP3A4, increasing metabolic clearance of apremilast.
What to do
Avoid combining; use a non-inducing antiseizure drug or another psoriasis therapy. Labeling advises against use with strong inducers.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Apremilast and Phenytoin, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
- Apremilast 10 mg, 20 mg, 30 mg Film-coated Tablets ( Treatment initiation pack) - SmPC sections 4.3/4.5 (names the partner; "h may result in a loss of efficacy of apremilast. Therefore, the use of strong CYP3A4 enzyme inducers (e.g. rifampicin, phenobarbital, carbamazepine, phenytoin ") — electronic medicines compendium (UK SmPC)
Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Other interactions of Apremilast
Frequently asked questions
Can I take Apremilast with Phenytoin?
MediHelp rates the interaction as major. Apremilast and Phenytoin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Phenytoin substantially lowers apremilast exposure, which can cause loss of therapeutic effect in psoriasis or related conditions.
How serious is the interaction between Apremilast and Phenytoin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combining; use a non-inducing antiseizure drug or another psoriasis therapy. Labeling advises against use with strong inducers.
What other medicines interact with Phenytoin?
MediHelp also lists interactions of Phenytoin with, for example, Artemether / lumefantrine, Bictegravir, Cabotegravir. The full list is on the Phenytoin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
