Does Digoxin Interact with Quinidine Sulfate Tablet?
Digoxin and Quinidine Sulfate Tablet have a major drug interaction according to U.S. FDA drug labeling data. Quinidine slows elimination of digoxin and reduces its volume of distribution, potentially doubling serum digoxin levels; digoxin dose reduction usually needed. The mechanism involves reduced elimination and decreased volume of distribution. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Major
- Digoxin Class
- Cardiac Glycoside
- Management
- Close medical supervision required
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Digoxin and Quinidine Sulfate Tablet occurs because reduced elimination and decreased volume of distribution. Clinically, this means quinidine slows elimination of digoxin and reduces its volume of distribution, potentially doubling serum digoxin levels; digoxin dose reduction usually needed. This is classified as a major interaction, meaning it could cause serious harm if not properly managed. Your healthcare provider may need to adjust dosages, substitute one medication, or increase monitoring frequency.
What To Tell Your Doctor or Pharmacist
If you are taking Digoxin and your doctor is considering prescribing Quinidine Sulfate Tablet (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask how frequently you should be monitored while these are co-prescribed
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider