Amoxicillin and Methotrexate: Drug Interaction Guide

Quick answer: This combination requires caution. Amoxicillin and Methotrexate can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Amoxicillin interacts with Methotrexate

Penicillins compete with methotrexate for renal tubular secretion via organic anion transporters, reducing methotrexate clearance and increasing toxicity.

What you should do

Avoid concurrent use during high-dose methotrexate therapy; for low-dose weekly methotrexate, monitor for stomatitis, cytopenias, and renal function.

Key facts

Severity

Moderate — caution required

Mechanism

Penicillins compete with methotrexate for renal tubular secretion via organic anion transporters, reducing methotrexate ...

Action

Avoid concurrent use during high-dose methotrexate therapy; for low-dose weekly methotrexate, monitor for stomatitis, cy...

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Amoxicillin and Methotrexate together?

With caution. Avoid concurrent use during high-dose methotrexate therapy; for low-dose weekly methotrexate, monitor for stomatitis, cytopenias, and renal function.

What is the severity of this interaction?

The interaction between Amoxicillin and Methotrexate is classified as Moderate — caution required. Penicillins compete with methotrexate for renal tubular secretion via organic anion transporters, reducing methotrexate clearance and increasing toxicity.

What should I do if I'm prescribed both?

Avoid concurrent use during high-dose methotrexate therapy; for low-dose weekly methotrexate, monitor for stomatitis, cytopenias, and renal function. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.