Does Cimetidine Interact with Doxazosin Mesylate?
Cimetidine and Doxazosin Mesylate have a minor drug interaction according to U.S. FDA drug labeling data. Cimetidine administration resulted in 10% increase in doxazosin AUC with slight but not significant increases in Cmax and half-life. The mechanism involves hepatic metabolism 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
- Minor
- Cimetidine Class
- Histamine-2 Receptor Antagonist
- Management
- Generally manageable
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Cimetidine and Doxazosin Mesylate occurs because hepatic metabolism inhibition. Clinically, this means cimetidine administration resulted in 10% increase in doxazosin auc with slight but not significant increases in cmax and half-life. 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 Cimetidine and your doctor is considering prescribing Doxazosin Mesylate (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