Overview
Avanafil is a phosphodiesterase 5 (PDE5) inhibitor used for the treatment of erectile dysfunction in adult males. It works by enhancing blood flow to the penis during sexual stimulation. Clinical trials demonstrate improved erectile response compared to placebo, with effects observed within 20-40 minutes after dosing.
Mechanism of Action
Avanafil selectively inhibits phosphodiesterase type 5 (PDE5), an enzyme that degrades cyclic guanosine monophosphate (cGMP) in the corpus cavernosum. This inhibition increases cGMP levels, leading to smooth muscle relaxation and increased blood flow to the penis during sexual stimulation, facilitating erection.
Indications
- Treatment of erectile dysfunction in adult males
Common Doses
- 50 mg
- 100 mg
- 200 mg
Dosage
The recommended starting dose is 100 mg taken approximately 30 minutes before sexual activity, with a maximum dose of 200 mg once daily. Dose adjustment may be needed based on efficacy and tolerability, particularly with concomitant medications.
Contraindications
- Concomitant use with nitrates in any form (due to risk of severe hypotension)
- Hypersensitivity to avanafil or any component of the formulation
Side Effects
- Headache
- Flushing
- Nasal congestion
- Back pain
- Dyspepsia
- Dizziness
- Visual disturbances (blue-green color discrimination changes)
Interactions
- Nitrates (contraindicated due to severe hypotension)
- Alpha-blockers (increased risk of hypotension)
- Strong CYP3A4 inhibitors (increase avanafil exposure - dose adjustment required)
- Alcohol (may increase hypotensive effects)
- Antihypertensives (additive hypotensive effects)
Counseling Points
- Take approximately 30 minutes before sexual activity
- Do not take more than once daily
- Avoid concomitant use with nitrates
- Seek immediate medical attention for erection lasting >4 hours
- Report chest pain, dizziness, or vision changes
- May cause temporary blue-green color discrimination changes