Dofetilide and Trimethoprim: Drug Interaction Guide

Quick answer: This is a major interaction — avoid combining Dofetilide and Trimethoprim unless specifically directed by your doctor.

Interaction severity: Major — avoid combination

How Dofetilide interacts with Trimethoprim

Trimethoprim inhibits renal cation transport involved in dofetilide elimination. Increased dofetilide exposure can prolong QT interval and precipitate torsades de pointes.

What you should do

Contraindicate or avoid the combination. Use an alternative antibiotic and monitor ECG if there has been recent exposure.

Key facts

Severity

Major — avoid combination

Mechanism

Trimethoprim inhibits renal cation transport involved in dofetilide elimination. Increased dofetilide exposure can prolo...

Action

Contraindicate or avoid the combination. Use an alternative antibiotic and monitor ECG if there has been recent exposure...

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 Dofetilide and Trimethoprim together?

No — this combination should generally be avoided. Contraindicate or avoid the combination. Use an alternative antibiotic and monitor ECG if there has been recent exposure.

What is the severity of this interaction?

The interaction between Dofetilide and Trimethoprim is classified as Major — avoid combination. Trimethoprim inhibits renal cation transport involved in dofetilide elimination. Increased dofetilide exposure can prolong QT interval and precipitate torsades de pointes.

What should I do if I'm prescribed both?

Contraindicate or avoid the combination. Use an alternative antibiotic and monitor ECG if there has been recent exposure. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

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