Methotrexate and Phenoxymethylpenicillin: Drug Interaction Guide

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

Interaction severity: Moderate — caution required

How Methotrexate interacts with Phenoxymethylpenicillin

Penicillins may reduce renal tubular secretion of methotrexate, increasing methotrexate exposure and toxicity risk.

What you should do

Use caution, particularly with high-dose methotrexate or renal impairment; monitor blood count, renal function, and mucositis.

Key facts

Severity

Moderate — caution required

Mechanism

Penicillins may reduce renal tubular secretion of methotrexate, increasing methotrexate exposure and toxicity risk.

Action

Use caution, particularly with high-dose methotrexate or renal impairment; monitor blood count, renal function, and muco...

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 Methotrexate and Phenoxymethylpenicillin together?

With caution. Use caution, particularly with high-dose methotrexate or renal impairment; monitor blood count, renal function, and mucositis.

What is the severity of this interaction?

The interaction between Methotrexate and Phenoxymethylpenicillin is classified as Moderate — caution required. Penicillins may reduce renal tubular secretion of methotrexate, increasing methotrexate exposure and toxicity risk.

What should I do if I'm prescribed both?

Use caution, particularly with high-dose methotrexate or renal impairment; monitor blood count, renal function, and mucositis. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

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