RECOVERY OF ERECTILE FUNCTION BY THE ORAL-ADMINISTRATION OF APOMORPHINE

Objectives. Apomorphine has been reported to be effective in causing e rections in animals and man when administered parenterally. The side e ffects, notably nausea, have seriously limited its clinical usefulness . We formulated apomorphine for controlled sublingual absorption and h erein report on four preliminary studies evaluating efficacy and side effects in men with no documentable organic cause of erectile dysfunct ion. Methods. Patients complaining of erectile dysfunction underwent a careful evaluation. Those with measurable organic dysfunction or know n organic factors were excluded. Men with primarily psychogenic impote nce were tested with one of four protocols of an apomorphine preparati on (preliminary sublingual liquid, preliminary 5 mg tablet, aqueous na sal spray, and new 3 and 4 mg controlled absorption tablets). The erec tile response of these men to the drug with visual erotic or sexually neutral stimulation was studied with the Rigiscan. Results. Seven of 1 0 evaluable patients responded to the sublingual liquid preparation bu t the majority experienced significant nausea. The preliminary 5 mg ta blet and aqueous forms did not produce useful responses free of side e ffects. The newly formulated controlled absorption 3 and 4 mg tablets were tested in 12 men. Eight of 12 (67%) developed erections in respon se to apomorphine. Erectile activity was seen during sexually neutral visual stimulation to a significantly greater extent than with placebo . Home trial use was found to be successful and sustained by 7 of 11 ( 64%) patients. Conclusions. We have shown that apomorphine will act as an erectogenic agent when absorbed through the oral mucosa. in a care fully selected group of impotent patients with no documentable organic causes of erectile dysfunction, but with proven erectile potential, 6 7% will experience significantly durable erections with a dose of 3 or 4 mg of apomorphine when formulated for controlled absorption. The re sults in these small groups appear to justify larger clinical studies of this proprietary formulation.