title: Long-term efficacy and safety of oral Viagra (sildenafil citrate) in men with erectile dysfunction and the effect of randomised treatment withdrawal.
abstract: The long-term efficacy and safety of oral Viagra (sildenafil citrate), a selective phosphodiesterase 5 inhibitor, and the effect of withdrawing treatment were evaluated in men with erectile dysfunction (ED). In 233 men with ED of psychogenic or mixed organic/psychogenic aetiology, 16 weeks of open-label, flexible-dose sildenafil treatment (10-100 mg) was followed by eight weeks of double-blind, fixed-dose, randomised withdrawal to placebo or continued treatment with sildenafil. Sildenafil was taken as needed (not more than once daily) approximately 1 h prior to sexual activity. The main outcome measures were a global efficacy question, a sexual function questionnaire, an event log of erections, and adverse event recording. In the open-label phase, 200 of 216 patients (93%) reported improved erections with sildenafil; 28 patients (12%) discontinued treatment. In the double-blind phase, the significant improvements in the frequency and duration of erections were maintained in the sildenafil group but returned to pre-treatment values in patients on placebo (P values < 0.0001 versus placebo). The most frequent adverse events in the sildenafil group during the double-blind phase were flushing (7%), headache (6%), and dyspepsia (5%). Of the 192 patients enrolled in the 1-y extension, 90% completed the study; only two patients (1%) were withdrawn due to lack of efficacy. In men with ED of psychogenic or mixed aetiology, oral sildenafil is effective and well-tolerated both at the initiation of therapy and during long-term treatment. For most patients, sildenafil treatment must be continued for improvements in erectile function to be maintained.
authors.affiliation: Andrology Center, Oslo, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Christiansen
authors.forename: W R
authors.initials: WR
authors.lastname: Guirguis
authors.forename: D
authors.initials: D
authors.lastname: Cox
authors.forename: I H
authors.initials: IH
authors.lastname: Osterloh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D007172:Erectile Dysfunction / Q000188:drug therapy* / Q000523:psychology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010410:Penile Erection; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D010879:Piperazines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D010919:Placebos; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D016896:Treatment Outcome
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D010919:Placebos; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate