Long-term efficacy and safety of oral Viagra (R) (sildenafil citrate) in men with erectile dysfunction and the effect of randomised treatment withdrawal

The long-term efficacy and safety of oral Viagra(R) (sildenafil citrate), a selective phosphodiesterase 5 inhibitor, and the effect of withdrawing tre atment were evaluated in men with erectile dysfunction (ED). In 233 men wit h ED of psychogenic or mixed organic/psychogenic aetiology, 16 weeks of ope n-label, flexible-dose sildenafil treatment (10 - 100 mg) was followed by e ight weeks of double-blind, fixed-dose, randomised withdrawal to placebo or continued treatment with sildenafil, Sildenafil was taken as needed (not m ore than once daily) approximately Ih prior to sexual activity. The main ou tcome measures were a global efficacy question, a sexual function questionn aire, an event log of erections, and adverse event recording, In the open-l abel phase, 200 of 216 patients (93%) reported improved erections with sild enafil; 28 patients (12%) discontinued treatment. In the double-blind phase , the significant improvements in the frequency and duration of erections w ere maintained in the sildenafil group but returned to pre-treatment values in patients on placebo (P values < 0.0001 versus placebo). The most Freque nt adverse events in the sildenafil group during the double-blind phase wer e flushing (7%), headache (6%), and dyspepsia (5%), Of the 192 patients enr olled in the 1-y extension, 90% completed the study; only two patients (1%) were withdrawn due to lack of efficacy. Tn men with ED of psychogenic or m ixed aetiology, oral sildenafil is effective and well-tolerated both at the initiation of therapy and during long-term treatment. For most patients, s ildenafil treatment must be continued for improvements in erectile function to be maintained.