Does Vardenafil Hydrochloride Interact with Ritonavir?
Vardenafil Hydrochloride and Ritonavir have a unknown drug interaction according to U.S. FDA drug labeling data. [See Dosage and Administration (2.4) and Warnings and Precautions (5.2) .] Ritonavir (600 mg b.i.d.) co-administered with vardenafil hydrochloride tablets 5 mg resulted in a 49-fold increase in vardenafil AUC and a 13 fold increase in vardenafil C max . The interaction is a consequence of blocking hepatic metabolism of vardenafil by ritonavir, a HIV protease inhibitor and a highly strong CYP3A4 inhibitor, which also inhibits CYP2C9. Ritonavir significantly prolonged the half-life of vardenafil to 26 hours. 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
- Unknown
- Vardenafil Hydrochloride Class
- Phosphodiesterase 5 Inhibitor
- Ritonavir Class
- Cytochrome P450 3A Inhibitor
- Management
- Consult your pharmacist
- Data Source
- U.S. FDA via OpenFDA
What To Tell Your Doctor or Pharmacist
If you are taking Vardenafil Hydrochloride and your doctor is considering prescribing Ritonavir (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