Does Theophylline Interact with Cetirizine Hydrochloride?
Theophylline and Cetirizine Hydrochloride have a minor drug interaction according to U.S. FDA drug labeling data. Small decrease in clearance of cetirizine at low-dose theophylline; larger doses may have greater effect. The mechanism involves decreased clearance. 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
- Theophylline Class
- Methylxanthine
- Management
- Generally manageable
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Theophylline and Cetirizine Hydrochloride occurs because decreased clearance. Clinically, this means small decrease in clearance of cetirizine at low-dose theophylline; larger doses may have greater effect. 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 Theophylline and your doctor is considering prescribing Cetirizine Hydrochloride (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