Does Ketoconazole Interact with Tadalafil?
Ketoconazole and Tadalafil have a contraindicated drug interaction according to U.S. FDA drug labeling data. Potent CYP3A inhibitor; avoid use of tadalafil in patients taking ketoconazole. The mechanism involves potent inhibition of cyp3a, the enzyme involved in tadalafil metabolism. 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
- Contraindicated
- Ketoconazole Class
- Azole Antifungal
- Tadalafil Class
- Phosphodiesterase 5 Inhibitor
- Management
- Do not take together
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Ketoconazole and Tadalafil occurs because potent inhibition of cyp3a, the enzyme involved in tadalafil metabolism. Clinically, this means potent cyp3a inhibitor; avoid use of tadalafil in patients taking ketoconazole. Because of the severity of this interaction, these medications are contraindicated — meaning they should not be taken together under any circumstances. If you are currently taking both, contact your healthcare provider immediately to discuss alternatives.
What To Tell Your Doctor or Pharmacist
If you are taking Ketoconazole and your doctor is considering prescribing Tadalafil (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 about alternative medications that do not interact with your current regimen
- Ask how frequently you should be monitored while these are co-prescribed
- Never stop or change either medication without first consulting your healthcare provider