Sildenafil is indicated for the treatment of erectile dysfunction (ED) in adult males. 

Erectile Dysfunction

• The recommended starting dose is 50 mg orally, taken as needed, approximately 1 hour before sexual activity.
• The dose may be increased to 100 mg or decreased to 25 mg based on tolerability and effectiveness.
• The maximum recommended dosing frequency is once per day.
• Sildenafil should not be taken with a high-fat meal as it may delay the onset of action.

Most common adverse reactions include:

• headache
• flushing
• dyspepsia
• abnormal vision
• nasal congestion
• back pain
• myalgia
• nausea
• dizziness
• rash

Headache	Flushing	Dyspepsia	Congestion
Back Pain	Myalgia	Dizziness	Rash

• If sexual activity is not advisable due to cardiovascular status, Sildenafil should not be used by patients. 
• Patients with a predisposition to priapism should use Sildenafil with caution and seek emergency treatment if an erection lasts for more than 4 hours. 
• Patients should stop using Sildenafil and seek medical care immediately if they experience sudden loss of vision in one or both eyes, which could indicate nonarteritic anterior ischemic optic neuropathy (NAION). Patients with a history of NAION should only use Sildenafil with caution when the expected benefits outweigh the risks. Patients with a "crowded" optic disc may also be at higher risk of NAION.
• Patients should seek prompt medical attention if they experience sudden decrease or loss of hearing while using Sildenafil. 
• Caution should be taken when co-administering Sildenafil with alpha-blockers or antihypertensives, as it may lead to hypotension. 
• Higher sildenafil exposures may cause decreased blood pressure, syncope, and prolonged erection. Sildenafil exposure is increased in patients taking strong CYP inhibitors like ritonavir, and a decrease in Sildenafil dosage is recommended.