[Effectiveness and safety of cavernous body auto-injection therapy with papaverine/phentolamine. Study group]

A multicenter long-term study at 13 urologic clinics in Germany and Austria tested the efficacy and safety of a papaverine (15 mg/ml) and phentolamine (0.5 mg/ml) mixture (ANDROSKAT) in achievement of pharmacologically aided erection. The study population of 157 men with chronic erectile dysfunction received a total of 559 injections administered by physicians, to establish the individual minimal dose of the mixture needed by each patient for a rigid erection. Rigidity sufficient for intercourse was achieved by 94% of these men. In the second phase of the study, 92 men administered a total of 4717 self-injections (mean 51.2, SD 7.7), with an average follow-up of 14 months. The mean therapeutic dose was 1.02 ml (SD 0.72). The latency time to full erection averaged 10.3 min (SD 5.5). The average duration of the erection induced was 67.1 min (SD 40.8, min. 11.2, max. 236). Sexual intercourse, orgasm and ejaculation were reported following 90%, 88% and 86%, respectively, of all injections. In the initial diagnostic phase, prolonged erections were seen in 13 patients (3%) and minor bruises at the injection site in 12 men. Side effects of self-injection during home therapy were pain (1.2%), haematoma (2.6%) and prolonged erection (0.9%). We conclude that self-injection with a combination of papaverine and phentolamine is an efficient and safe long-term treatment for erectile dysfunction.