HEMODYNAMIC EFFECTS OF TRANSURETHRAL ALPROSTADIL MEASURED BY COLOR DUPLEX ULTRASONOGRAPHY IN MEN WITH ERECTILE DYSFUNCTION

Purpose

We evaluated the hemodynamic effects of transurethral alprostadil in 21 patients with erectile dysfunction using color duplex ultrasonography.

Materials and Methods

Penile arterial diameter, peak flow velocity and end diastolic velocity were compared following intraurethral administration of 500 micro g. alprostadil and intracavernosal injection of 10 micro g. alprostadil.

Results

A dose of 500 micro g. transurethral alprostadil resulted in significant increases in corporeal blood flow comparable to those achieved with intracavernosal injection of 10 micro g. alprostadil as measured by duplex ultrasonography in men with erectile dysfunction. Transurethral alprostadil resulted in statistically significant increases in arterial diameter and peak flow velocity comparable to those achieved with intracavernosal injection. End diastolic velocities were higher after transurethral alprostadil than intracavernosal injections. Color ultrasonography following transurethral alprostadil showed arterial and venous hyperemia of the corpus spongiosum and corpora cavernosa. Furthermore, color ultrasonography revealed communicating vessels between the corpus spongiosum and corpora cavernosa following administration of transurethral alprostadil.

Conclusions

The visualization of communicating vessels between the corpus spongiosum and corpora cavernosa after transurethral alprostadil suggests local mechanisms of drug transfer from one to the other. In addition to potential clinical benefits, transurethral alprostadil may be useful to visualize the vascular anatomy of the penis and to test for patient responsiveness to local vasoactive agents.     

ERECTILE RESPONSE TO TRANSURETHRAL ALPROSTADIL, PRAZOSIN AND ALPROSTADIL-PRAZOSIN COMBINATIONS

Purpose

Transurethral alprostadil has been shown to be efficacious in many men with erectile dysfunction. We compared transurethral alprostadil and prazosin alone, and in combination to treat this disorder.

Materials and Methods

In this double-blind, placebo controlled study the erectile responses to transurethral alprostadil, prazosin and alprostadil-prazosin combinations were assessed in 234 men 26.8 to 8.15 years old with complete organic erectile dysfunction. Patients self-administered a random sequence of 7 doses in the clinic in 4 weeks. The erectile response was assessed using categorical and visual analog scales.

Results

Full penile enlargement or rigidity was achieved by 165 of the 234 men (70.5%) after at least 1 active dose of medication. The most effective alprostadil dose (500 micro g.) resulted in full penile enlargement or rigidity in 51.8% of administrations, whereas the most effective prazosin dose (2,000 micro g.) and placebo resulted in a similar response in 12.7 and 2.7%, respectively (p <0.001). The 500/2,000 micro g. alprostadil/prazosin combination, which resulted in full enlargement or rigidity in 58.9% of doses, was only slightly better than the most effective dose of alprostadil alone (500 micro g.). However, combinations of 125/500 and 250/500 micro g. alprostadil/prazosin were more effective (p <0.01) than 125 and 250 micro g. alprostadil given alone, respectively. The most common side effect of therapy was penile pain, which rarely led to study discontinuation. Hypotension most commonly developed at the higher alprostadil-prazosin combination.

Conclusions

Transurethral alprostadil and alprostadil-prazosin combinations produced erections in men with complete organic erectile dysfunction. This combination therapy may be an option in patients who do not respond to transurethral alprostadil alone.