Drug interactions
Methoxsalen + Pirfenidone
Severity: Major
Methoxsalen and Pirfenidone: major 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
Methoxsalen is a potent CYP1A2 inhibitor and can substantially increase pirfenidone exposure. This raises the risk of nausea, rash, photosensitivity and liver enzyme elevation, and methoxsalen photosensitization compounds the phototoxicity.
What this interaction means in plain words
Methoxsalen and Pirfenidone 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.
Methoxsalen belongs to Anti Fungals; Pirfenidone belongs to Miscellaneous.
Why it happens
Inhibition of CYP1A2 by methoxsalen reduces pirfenidone clearance.
What to do
Avoid the combination; if a strong CYP1A2 inhibitor is essential, reduce the pirfenidone dose per labeling and monitor liver tests and skin reactions with strict sun protection.
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?
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Other interactions of Methoxsalen
- Fezolinetant + Methoxsalen Contraindicated
- Demeclocycline + Methoxsalen Major
- Fedratinib + Methoxsalen Major
- Methoxsalen + Tasimelteon Major
- Adapalene + Methoxsalen Moderate
- Amlodipine-hydrochlorothiazide-valsartan + Methoxsalen Moderate
Other interactions of Pirfenidone
Frequently asked questions
Can I take Methoxsalen with Pirfenidone?
MediHelp rates the interaction as major. Methoxsalen and Pirfenidone 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. Methoxsalen is a potent CYP1A2 inhibitor and can substantially increase pirfenidone exposure. This raises the risk of nausea, rash, photosensitivity and liver enzyme elevation, and methoxsalen photosensitization compounds the phototoxicity.
How serious is the interaction between Methoxsalen and Pirfenidone?
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 the combination; if a strong CYP1A2 inhibitor is essential, reduce the pirfenidone dose per labeling and monitor liver tests and skin reactions with strict sun protection.
What other medicines interact with Methoxsalen?
MediHelp also lists interactions of Methoxsalen with, for example, Fezolinetant, Demeclocycline, Fedratinib. The full list is on the Methoxsalen page.
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