Adenosine: a new agent in the diagnosis of impotence.

The haemodynamic effects of different dosages of adenosine were studied using colour flow Doppler sonography (CFDS) in 33 men, whose penile vascular bed responded well to papaverine. In six cases, we injected 25, 50, 100, 250 micrograms dosages of adenosine intracavernously at 15 min intervals and no erection occurred. However, 500 and 1000 micrograms doses of adenosine increased the arterial blood velocities for a few seconds in five cases. Later on, in eight cases, we infused 80 and 120 micrograms/kg/min adenosine for 3 min and only with 120 micrograms/kg/min dosage, did we observe clinical response and significant changes in CFDS parameters. Finally, 120 micrograms/kg/min adenosine dosage was infused for 10 min in 14 men and eight showed full erection while six had only tumescence. As adenosine was rapidly metabolized by adenosine deaminase, the erection lasted for only 5 to 13 min. No prolonged erection and no other side-effect was observed. In addition no fibrosis and curvature was detected 6 months after the injections. We found that, in men, 10 min infusion of 120 micrograms/kg/min adenosine increased the arterial flow and to some extent venous resistance, resulting in full erection or tumescence. Therefore, adenosine may be used as an agent for the diagnosis of vasculogenic impotence, but further studies for determining the standard dosage of adenosine are needed.