Does Tolcapone Interact with Digitoxin?
Tolcapone and Digitoxin have a minor drug interaction according to U.S. FDA drug labeling data. In vitro protein binding studies showed tolcapone did not displace digitoxin from binding sites at therapeutic concentrations. The mechanism involves protein binding interaction (no clinically relevant effect demonstrated). 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
- Minor
- Tolcapone Class
- Catechol-O-Methyltransferase Inhibitor
- Management
- Generally manageable
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Tolcapone and Digitoxin occurs because protein binding interaction (no clinically relevant effect demonstrated). Clinically, this means in vitro protein binding studies showed tolcapone did not displace digitoxin from binding sites at therapeutic concentrations. This is classified as a minor interaction with generally low clinical significance, though your healthcare provider should still be informed that you are taking both medications.
What To Tell Your Doctor or Pharmacist
If you are taking Tolcapone and your doctor is considering prescribing Digitoxin (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
- Never stop or change either medication without first consulting your healthcare provider