Does Losartan Potassium Interact with Ketoconazole?
Losartan Potassium and Ketoconazole have a minor drug interaction according to U.S. FDA drug labeling data. Conversion of losartan to its active metabolite after intravenous administration is not affected by ketoconazole. The mechanism involves cyp450 3a4 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
- Ketoconazole Class
- Azole Antifungal
- Management
- Generally manageable
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Losartan Potassium and Ketoconazole occurs because cyp450 3a4 inhibition. Clinically, this means conversion of losartan to its active metabolite after intravenous administration is not affected by ketoconazole. 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 Losartan Potassium and your doctor is considering prescribing Ketoconazole (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