Recommended Dose: The recommended starting dose is 10 mg taken orally approximately 25–60 minutes before sexual activity. The dose may be adjusted to 5 mg or increased to a maximum of 20 mg according to efficacy and tolerability. Do not exceed one dose within 24 hours.

Time: Take as needed before sexual activity. Food may delay the onset of action, especially with high-fat meals.

Instructions for use: Swallow the tablet whole with water. Sexual stimulation is required for the effect. Avoid excessive alcohol consumption and seek medical attention for erection lasting more than 4 hours or sudden vision/hearing changes.

Interaction: Do not use with nitrates, nitric oxide donors, or guanylate cyclase stimulators due to the risk of severe hypotension. Strong CYP3A4 inhibitors are contraindicated. Use caution with moderate CYP3A4 inhibitors, antihypertensive drugs, and α-blockers because of increased hypotension risk.

Side effects: Common adverse reactions include headache, flushing, nasal congestion, dizziness, and indigestion. Other reactions may include back pain, muscle pain, nausea, palpitations, and visual disturbances. Rare serious reactions include priapism, sudden vision loss, hearing loss, severe hypotension, allergic reactions, and cardiovascular events.