Overview
Vardenafil is a phosphodiesterase type 5 (PDE5) inhibitor used to treat erectile dysfunction by enhancing blood flow to the penis during sexual stimulation. It requires sexual arousal to be effective and is contraindicated with nitrates due to potentially life-threatening hypotension.
Mechanism of Action
Vardenafil selectively inhibits phosphodiesterase type 5 (PDE5), increasing cyclic guanosine monophosphate (cGMP) levels in the corpus cavernosum. This enhances nitric oxide-mediated vasodilation, improving blood flow to the penis during sexual stimulation.
Indications
- Treatment of erectile dysfunction
Common Doses
- 5 mg
- 10 mg
- 20 mg
Dosage
Typically administered as needed approximately 60 minutes before sexual activity. Starting dose is usually 10 mg, which may be adjusted based on efficacy and tolerability to 5 mg or increased to 20 mg. Maximum recommended dosing frequency is once daily.
Contraindications
- Concomitant use with nitrates or nitric oxide donors
- Hypersensitivity to vardenafil or any component of the formulation
- Concurrent use with guanylate cyclase stimulators (e.g., riociguat)
Side Effects
- Headache
- Flushing
- Dyspepsia
- Nasal congestion
- Dizziness
- Back pain/myalgia
- Visual disturbances
- Hypotension
- Priapism
- Sudden hearing loss
- NAION
Interactions
- Nitrates (contraindicated)
- Alpha-blockers (risk of hypotension)
- Strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) - reduce vardenafil dose
- Guanylate cyclase stimulators (e.g., riociguat)
Counseling Points
- Take approximately 60 minutes before sexual activity
- Requires sexual stimulation for effectiveness
- Do not take with nitrates under any circumstances
- Seek immediate medical attention for erection lasting >4 hours
- Report sudden vision or hearing changes
- Avoid excessive alcohol consumption
- Inform healthcare provider of all medications being taken