A clinical comparative study on effects of intracavernous injection of sodium nitroprusside and papaverine/phentolamine in erectile dysfunction patients.

AIM: To study the effect of intracavernous sodium nitroprusside (SNP), a nitric oxide (NO) donor, on penile erection.

METHODS

Forty-two patients with erectile dysfunction (ED) were randomly assigned to receive SNP 300 micrograms or the control drugs (papaverine 30 mg + phentolamine 1 mg) intracavernously crosswise one week apart. The penile length, circumference and hardness after the administration of the experimental and control drugs were assessed and compared statistically.

RESULTS

(1) There was no significant difference between the changes in penile length and circumference in the two occasions; (2) In 25 SNP and 28 control cases, the hardness of the penis was scored above 100 as evaluated by the Virag method (P > 0.05); (3) The duration of erection in the controls was longer than that in the SNP, but there were three priapism in the controls and not a single one in the SNP; (4) there was no apparent change in the heart rate and blood pressure in both occasions; other side effects were minimal except slight local pain in a few controls.

CONCLUSION

SNP facilitates relaxation of the penile smooth muscle and penile erection without significant side effects. SNP may be used in ED patients that experience pain and priapism with papaverine/phentolamine.