Metformin and Sulfamethoxazole Trimethoprim: Drug Interaction Guide

Quick answer: This combination requires caution. Metformin and Sulfamethoxazole Trimethoprim can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Metformin interacts with Sulfamethoxazole Trimethoprim

Trimethoprim inhibits renal organic cation transporters involved in metformin clearance, potentially increasing metformin concentrations.

What you should do

Monitor renal function and glycaemic control; consider metformin dose adjustment or temporary interruption in patients with renal impairment or acute illness.

Key facts

Severity

Moderate — caution required

Mechanism

Trimethoprim inhibits renal organic cation transporters involved in metformin clearance, potentially increasing metformi...

Action

Monitor renal function and glycaemic control; consider metformin dose adjustment or temporary interruption in patients w...

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 Metformin and Sulfamethoxazole Trimethoprim together?

With caution. Monitor renal function and glycaemic control; consider metformin dose adjustment or temporary interruption in patients with renal impairment or acute illness.

What is the severity of this interaction?

The interaction between Metformin and Sulfamethoxazole Trimethoprim is classified as Moderate — caution required. Trimethoprim inhibits renal organic cation transporters involved in metformin clearance, potentially increasing metformin concentrations.

What should I do if I'm prescribed both?

Monitor renal function and glycaemic control; consider metformin dose adjustment or temporary interruption in patients with renal impairment or acute illness. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

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