Drug interactions
Methoxsalen + Sulfamethoxazole
Severity: Moderate
Methoxsalen and Sulfamethoxazole: 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
Sulfamethoxazole may cause photosensitivity, which can add to the phototoxicity of methoxsalen with UVA. The risk is increased burning or rash on light exposure.
What this interaction means in plain words
Methoxsalen and Sulfamethoxazole 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.
Why it happens
Additive photosensitizing effects (pharmacodynamic).
What to do
Advise strict photoprotection and monitor the skin during phototherapy, reducing UVA dose when needed. Use an alternative antibiotic if feasible.
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 Methoxsalen
- Fezolinetant + Methoxsalen Contraindicated
- Demeclocycline + Methoxsalen Major
- Fedratinib + Methoxsalen Major
- Methoxsalen + Pirfenidone Major
- Methoxsalen + Tasimelteon Major
- Adapalene + Methoxsalen Moderate
Frequently asked questions
Can I take Methoxsalen with Sulfamethoxazole?
MediHelp rates the interaction as moderate. Methoxsalen and Sulfamethoxazole 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. Sulfamethoxazole may cause photosensitivity, which can add to the phototoxicity of methoxsalen with UVA. The risk is increased burning or rash on light exposure.
How serious is the interaction between Methoxsalen and Sulfamethoxazole?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise strict photoprotection and monitor the skin during phototherapy, reducing UVA dose when needed. Use an alternative antibiotic if feasible.
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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