Digoxin and Quinidine: Drug Interaction Guide

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

Interaction severity: Major — avoid combination

How Digoxin interacts with Quinidine

Quinidine inhibits P-glycoprotein-mediated renal tubular and biliary digoxin elimination, doubling serum digoxin levels within 24-48 hours.

What you should do

Reduce digoxin dose by 50% at initiation of quinidine and monitor serum digoxin levels and ECG for signs of toxicity.

Key facts

Severity

Major — avoid combination

Mechanism

Quinidine inhibits P-glycoprotein-mediated renal tubular and biliary digoxin elimination, doubling serum digoxin levels ...

Action

Reduce digoxin dose by 50% at initiation of quinidine and monitor serum digoxin levels and ECG for signs of toxicity.

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 Digoxin and Quinidine together?

No — this combination should generally be avoided. Reduce digoxin dose by 50% at initiation of quinidine and monitor serum digoxin levels and ECG for signs of toxicity.

What is the severity of this interaction?

The interaction between Digoxin and Quinidine is classified as Major — avoid combination. Quinidine inhibits P-glycoprotein-mediated renal tubular and biliary digoxin elimination, doubling serum digoxin levels within 24-48 hours.

What should I do if I'm prescribed both?

Reduce digoxin dose by 50% at initiation of quinidine and monitor serum digoxin levels and ECG for signs of toxicity. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

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