Enalapril and Trimethoprim Sulfamethoxazole: Drug Interaction Guide

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

Interaction severity: Major — avoid combination

How Enalapril interacts with Trimethoprim Sulfamethoxazole

Trimethoprim blocks the renal epithelial sodium channel like a potassium-sparing diuretic; combined with ACE inhibitor-induced aldosterone suppression, severe hyperkalemia and sudden death can occur, especially in elderly patients.

What you should do

Avoid combination in elderly or renally impaired patients. If unavoidable, check serum potassium and creatinine within 3–5 days.

Key facts

Severity

Major — avoid combination

Mechanism

Trimethoprim blocks the renal epithelial sodium channel like a potassium-sparing diuretic; combined with ACE inhibitor-i...

Action

Avoid combination in elderly or renally impaired patients. If unavoidable, check serum potassium and creatinine within 3...

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 Enalapril and Trimethoprim Sulfamethoxazole together?

No — this combination should generally be avoided. Avoid combination in elderly or renally impaired patients. If unavoidable, check serum potassium and creatinine within 3–5 days.

What is the severity of this interaction?

The interaction between Enalapril and Trimethoprim Sulfamethoxazole is classified as Major — avoid combination. Trimethoprim blocks the renal epithelial sodium channel like a potassium-sparing diuretic; combined with ACE inhibitor-induced aldosterone suppression, severe hyperkalemia and sudden death can occur, especially in elderly patients.

What should I do if I'm prescribed both?

Avoid combination in elderly or renally impaired patients. If unavoidable, check serum potassium and creatinine within 3–5 days. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

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