Take once daily, about 1 hour before sexual activity. Initially 10mg; range: 5–20mg. Elderly (≥65yrs): initially 5mg. Moderate hepatic impairment: initially 5mg; max 10mg. Concomitant ketoconazole 200mg or itraconazole 200mg daily, or erythromycin: max 5mg. Concomitant indinavir, saquinavir, atazanavir, ketoconazole 400mg or itraconazole 400mg daily, clarithromycin: max 2.5mg. Concomitant ritonavir: max 2.5mg/72hrs. Concomitant α-blocker: initially 5mg/day.
Phosphodiesterase type 5 inhibitor (cGMP-specific).
Concomitant nitrates, or nitric oxide donors (eg, sodium nitroprusside).
Confirm diagnosis. Congenital QT prolongation: avoid use. Cardiovascular disease (eg, MI, stroke or life-threatening arrhythmia within 6 months; systolic BP <90 or BP >170/110; unstable angina, LV outflow obstruction, impaired autonomic regulation of BP, severe heart failure), severe hepatic impairment, renal dialysis, retinitis pigmentosa and related retinal disorders: not recommended. Anatomical penile deformation. Predisposition to priapism. Patients for whom sexual activity is inadvisable or contraindicated. Bleeding disorders. Active peptic ulcer. Pregnancy (Cat.B).
See Contraindications. Avoid class IA or III antiarrhythmics, others that cause QT prolongation. Hypotension with nitrates, α-blockers, other antihypertensives. Plasma levels increased by CYP3A4 inhibitors. Concomitant other erectile dysfunction treatments: not recommended.
Headache, flushing, rhinitis, dyspepsia, sinusitis, dizziness, sudden vision or hearing loss (discontinue if occurs), cardiovascular effects (eg, hypotension, tachycardia); rare: priapism.