Does Peginterferon Alfa 2a Interact with Theophylline?
Peginterferon Alfa 2a and Theophylline have a moderate drug interaction according to U.S. FDA drug labeling data. PEGASYS inhibits CYP1A2, increasing theophylline AUC by 25%. Monitor serum levels and adjust dose accordingly. The mechanism involves cyp1a2 inhibition. 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
- Moderate
- Peginterferon Alfa 2a Class
- Interferon alpha
- Theophylline Class
- Methylxanthine
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Peginterferon Alfa 2a and Theophylline occurs because cyp1a2 inhibition. Clinically, this means pegasys inhibits cyp1a2, increasing theophylline auc by 25%. monitor serum levels and adjust dose accordingly. This is classified as a moderate interaction. While it may not require stopping either medication, your healthcare provider should be aware you are taking both so they can monitor for potential effects and adjust treatment if necessary.
What To Tell Your Doctor or Pharmacist
If you are taking Peginterferon Alfa 2a and your doctor is considering prescribing Theophylline (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 whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider