Intracavernous pharmacotherapy

Abstract

Intracavernous application of vasoactive substances not only has enhanced our understanding of penile hemodynamics, the physiology of penile erection, and the pathophysiology of erectile dysfunction but also has revolutionized the diagnosis and treatment of erectile dysfunction in the last 15 years. Virag was the first to report on the erectile effect of papaverine in humans, and Brindley later reported the effect of intracavernous application of alpha-receptor-blocking agents on cavernous tissue. These reports led to numerous basic and clinical investigations and ultimately established a new treatment alternative for patients with erectile dysfunction that is now considered to be the treatment of choice for most patients. Changes in penile hemodynamics include the relaxation of cavernous smooth musculature and arteries, which leads to an increase in arterial blood flow and a restriction of venous outflow through a compression of subtunical veins. These hemodynamic changes are the prerequisite for the induction and maintenance of penile erection. With the intracavernous application of vasoactive substances it was possible to influence penile hemodynamics at a local level and to induce an erection despite alterations in the nervous system, penile arterial blood flow, cavernous musculature, or neurotransmitter status. In addition, the local application of pharmacologically active substances directly to the end organ enabled the achievement of high local drug concentrations without severe systemic side effects. The commonly used substances are papaverine the combination of papaverine and phentolamine, and prostaglandin E1 (alprostadil). In addition to these established substances, several other regimens, such as linsidomine (SIN-1), calcitonin gene-related peptide (CGRP), moxisylyte, and various triple- or quadruple-drug mixtures have been described. In addition, several other compounds as well as different routes of administration are on the horizon and may prove to be effective in the future diagnosis and treatment of erectile dysfunction.

Effects of the specific phosphodiesterase inhibitors on alloxan-induced diabetic rabbit cavernous tissue in vitro

“…However, papaverine, a nonspeci®c PDE inhibitor, causes pain during injection, prolonged erections and cavernous ®brosis in a signi®cant number of patients. 18 Recent basic research …”

Medical treatment of erectile dysfunction. Current status and prospects

“…3±5 % der Patienten und in weniger als 1 % der Injektionen gesehen. Lokale Komplikationen (Schwellkörperfibrosen, Penisdeviationen, Hämatome, Schmerzen) werden in 1±7 % der Fälle gesehen (Truss et al 1997;Juenemann u. Alken 1989;Wetterauer 1991).…”

“…Aufgrund der intensivierten Forschungsanstrengungen zum Grundlagenwissen (Rampin et al 1997;Andersson u. Stief 1997;Shabsigh 1997) und zu den klinischen Anwendungen (Hartmann 1997;Truss et al 1997), die innerhalb der letzten Jahrzehnte auf den Gebiet des normalen und gestörten Erektionsmechanismus unternommen worden sind, steht Arzt und Patient ein breit gefächertes, wenn auch noch keineswegs zufriedenstellendes Angebot von Behandlungsmöglichkeiten gegenüber. Diese breite Palette von therapeutischen Optionen erlaubt in vielen Fällen die Möglichkeit eines weitgehenden Eingehens auf Wünsche und individuelle Gegebenheiten des Patienten.…”

Erectile Dysfunction and Anejaculation

“…The rate of prolonged erections and corporal fibrosis is way under 0.1%. Up to 20% of the patients report local pain after injection of PGE 1 , forcing them to give up this therapy or change to the abovementioned drug combination [21].…”