Avanafil

Indications

Avanafil is a phosphodiesterase 5 (PDE5) inhibitor indicated for the treatment of erectile dysfunction.

Pharmacology

Avanafil is a selective phosphodiesterase 5 (PDE5) enzyme inhibitor used for the treatment of erectile dysfunction caused by diabetes, age induced oxidative stress or other complications. Avanafil inhibits the cGMP specific phosphodiesterase 5 (PDE5) which is responsible for degradation of cGMP in the corpus cavernosum located around the penis. Penis erection during sexual stimulation is caused by increased penis blood flow resulting from the relaxation of penis arteries and corpus cavernosal smooth muscle. This response is mediated by the release of nitric oxide (NO) from nerve terminals and endothelial cells, which stimulates the synthesis of cGMP in smooth muscle cells. Cyclic GMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum. The inhibition of phosphodiesterase 5 (PDE5) by avanafil enhances erectile function by increasing the amount of cGMP.

Dosage & Administration

The recommended starting dose is 100 mg taken approximately 15 minutes before sexual activity, on an as needed basis. Avanafil may be taken with or without food. Avanafil must not be taken more than once a day. The dose may be increased to 200 mg or decreased to 50 mg based on efficacy and/or tolerability. Use the lowest dose that provides benefit. Concomitant use of nitrates in any form is contraindicated. Do not use Avanafil with strong CYP3A4 inhibitors. If taking a moderate CYP3A4 inhibitor, the dose should be no more than 50 mg in a 24-hour period. In patients on stable alpha-blocker therapy, the recommended starting dose of Avanafil is 50 mg.

Interaction

Avanafil can potentiate the hypotensive effect of nitrates, alphablockers, antihypertensives, and alcohol. CYP3A4 inhibitors (e.g., ketoconazole, ritonavir, erythromycin) increase Avanafil exposure

Contraindications

Administration of Avanafil to patients using any form of organic nitrate is contraindicated. Avanafil is contraindicated in patients with a known hypersensitivity to Avanafil. Administration of Avanafil with guanylate cyclase (GC) stimulators such as riociguat and vericiguat is contraindicated.

Side Effects

Most common adverse reactions (greater than or equal to 2%) include headache, flushing, nasal congestion, nasopharyngitis, and back pain.

Pregnancy & Lactation

Pregnancy Category C. Avanafil is not indicated for use in women.

Precautions & Warnings

Patients should not use Avanafil if sexual activity is inadvisable due to cardiovascular status or any other reason. Use of Avanafil with alpha-blockers, other antihypertensives, or substantial amounts of alcohol (greater than 3 units) may lead to hypotension.

Patients should seek emergency treatment if an erection lasts greater than 4 hours.

Patients should stop taking Avanafil and seek medical care if a sudden loss of vision occurs in one or both eyes, which could be a sign of

Non-Arteritic Ischemic Optic Neuropathy (NAION). Discuss with patients the increased risk of NAION in patients with a prior history of NAION.

Patients should stop taking Avanafil and seek prompt medical attention in the event of sudden decrease or loss of hearing.

Use in Special Populations

Pediatric Use: Avanafil is not indicated for use in pediatric patients.

Geriatric Use: Of the total number of subjects in clinical studies of Avanafil, approximately 23% were 65 and over. No overall differences in efficacy and safety were observed between subjects over 65 years of age compared to younger subjects; therefore, no dose adjustment is warranted based on age alone. However, a greater sensitivity to medication in some older individuals should be considered.

Renal & hepatic impairment patients: Do not use in patients with severe renal & hepatic impairment.

Overdose Effects

Single doses up to 800 mg have been given to healthy subjects, and multiple doses up to 300 mg have been given to patients. In cases of overdose, standard supportive measures should be adopted as required. Renal dialysis is not expected to accelerate clearance because avanafil is highly bound to plasma proteins and is not significantly eliminated in the urine.

Therapeutic Class

Drugs for Erectile Dysfunction

Storage Conditions

Store below 25°C temperature. Keep away from light and wet place. Keep out of reach of children.