Drug interactions
Methotrexate + Sepiapterin
Severity: Major
Methotrexate and Sepiapterin: 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
Sepiapterin must be reduced by dihydrofolate reductase to produce tetrahydrobiopterin. Methotrexate inhibits this enzyme and may reduce BH4 formation and weaken control of phenylalanine.
What this interaction means in plain words
Methotrexate and Sepiapterin 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.
Methotrexate belongs to Oncology; Sepiapterin belongs to Miscellaneous.
Why it happens
DHFR inhibition by methotrexate impairs conversion of sepiapterin to BH4.
What to do
Avoid the combination if possible. If unavoidable, monitor blood phenylalanine closely and adjust treatment.
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 Sepiapterin
- Pemetrexed + Sepiapterin Major
- Sepiapterin + Sulphasalazine Major
- Levodopa + Sepiapterin Moderate
- Sepiapterin + Sildenafil Moderate
- Sepiapterin + Tadalafil Moderate
- Sepiapterin + Vardenafil Moderate
Other interactions of Methotrexate
- Acitretin + Methotrexate Contraindicated
- Adenovirus types 4 and 7 live + Methotrexate Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Methotrexate Contraindicated
- Ketorolac + Methotrexate Contraindicated
- Measles mumps and rubella vaccine live + Methotrexate Contraindicated
- Measles mumps and rubella vaccine + Methotrexate Contraindicated
Frequently asked questions
Can I take Methotrexate with Sepiapterin?
MediHelp rates the interaction as major. Methotrexate and Sepiapterin 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. Sepiapterin must be reduced by dihydrofolate reductase to produce tetrahydrobiopterin. Methotrexate inhibits this enzyme and may reduce BH4 formation and weaken control of phenylalanine.
How serious is the interaction between Methotrexate and Sepiapterin?
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 possible. If unavoidable, monitor blood phenylalanine closely and adjust treatment.
What other medicines interact with Sepiapterin?
MediHelp also lists interactions of Sepiapterin with, for example, Pemetrexed, Sulphasalazine, Levodopa. The full list is on the Sepiapterin page.
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