Sildenafil citrate (Generic Viagra, Pfizer) is still the front-line treatment for men with erectile dysfunction (ED), but for men who do not respond to it, intraurethral alprostadil (Caverject®, Pfizer) might be a good next choice.
Researchers observed 44 men for up to 15 months. In 10 patients, ED was a result of radical retropubic prostatectomy. Nine patients also had hypertension, seven had diabetes, and eight had both conditions. Six men had drug-induced ED. In all, 13 patients (30%) responded well to intraurethral alprostadil.
Because the study was small, no statistically significant conclusions were able to be drawn. However, five of the 10 men who had undergone earlier radical retro-pubic prostatectomy reported improved erectile function: two who had received 500 mcg and three who had received 1,000 mcg.
Two patients with ED secondary to nonoperative factors improved with the lowest dose (250 mcg), but none who had undergone radical retropubic prostatectomy responded satisfactorily.
Intraurethral alprostadil acts directly to promote the inflow and retention of blood within the corpora; it does not rely on sexual stimulation or intact penile innervation. Because drug sildenafil and intra-urethral alprostadil work differently, they may be complementary treatments for patients who have not responded to one or the other. The researchers cite a study in which 90% of 65 patients experienced satisfactory results with combination therapy after monotherapy had failed.
One drawback of the study is that patients tried sildenafil tablet only five times before the treatment was considered unsuccessful (mainly because of cost). Other reports suggest that at least eight attempts should be made.