Hatzichristou, D G Sildenafil versus intracavernous injection therapy: efficacy and preference in patients on intracavernous injection for more than 1 year. [electronic resource] - The Journal of urology Oct 2000 - 1197-200 p. digital Publication Type: Comparative Study; Journal Article ISSN: 0022-5347 Subjects--Topical Terms: AdultAgedAlprostadil--administration & dosageHumansMaleMiddle AgedPhosphodiesterase Inhibitors--therapeutic usePiperazines--therapeutic usePurinesSildenafil CitrateSulfonesTreatment OutcomeVasodilator Agents--administration & dosage