Apomorphine SL: Evolution of a centrally acting treatment for erectile dysfunction

Erectile dysfunction has been described in the medical literature since ancient times. Developments in Western medicine included the development of vascular procedures, vacuum devices, penile implants, intracavernosal and intraurethral therapies, and most recently, oral drugs: sildenafil and sublingual apomorphine. Apomorphine has a central mechanism of action, but also reinforces peripheral neuronal pathways. The hypothalamus plays a critical role in the central command of penile erection. Erectile function also depends on neurotransmitters, most notably dopamine, serotonin, norepinephrine, oxytocin, and nitric oxide. Apomorphine has predominant D-2-like dopamine receptor agonist effects and acts primarily on the paraventricular nucleus of the hypothalamus, promoting the natural erectile phenomenon and assisting in the restoration of normal autonomic balance in the control of penile function. The drug has a long history of safety in humans and is absorbed rapidly by the oral mucosa. Onset of action is rapid-usually within 20 minutes of administration. The most distinct adverse effects of the drug are nausea, dizziness and yawning. Potential drug interactions are unlikely. The drug has no addictive or analgesic properties. Clinical trials indicate that sublingual apomorphine is effective in helping men with erectile dysfunction achieve satisfactory penile erections. (C) 2002 Published by Elsevier Science B.V.