Reasons for high drop-out rate with self-injection therapy for impotence.

One hundred and eighty patients, average age of 58 years (range 24-75) were evaluated for impotence and were advised to undergo pharmacologic self-injection therapy with either papaverine/Regitine (90%) or prostaglandin E1 (10%). Follow-up was available from 2 months to 3 years (average 11 months). The cause of impotence was determined by hormonal testing, Rigiscan and psychological testing. The etiology of impotence was organic (70%), psychogenic (20%), and mixed (10%). After the initial test injection 22% of patients did not enroll in the self-injection program or were lost to follow-up. The group with psychogenic impotence had the highest satisfaction/usage rate at 42%. Overall only 20% of patients were satisfied long-term and were actively using self-injection therapy. Of the 140 patients available for follow-up, 112 patients (80%) discontinued self-injection therapy. The reasons for discontinued usage were alternate treatment (prosthesis or vacuum device) 15%, return or improvement of erections 8%, partner dissatisfaction or loss of partner 10%, or complications of injection therapy 10%. Cost was not a factor for discontinued use. Loss of interest caused 57% of patients to stop using self-injection therapy. Although pharmacologic self-injection therapy is initially promising there is a high drop-out rate at long-term follow-up.