Chronic Papaverine Treatment: The Effect of Repeated Injections on the Simian Erectile Response and Penile Tissue

Abstract

To investigate the effect of chronic papaverine treatment, seven monkeys underwent repeated intracavernous injections for one year. One monkey died after 56 injections; the others received a total of 100 each. The strength and duration of erection were recorded after each injection, and the erectile tissue was examined histologically at the end of the study. Over the long term, papaverine maintains its erection-inducing capability, but it does cause pathologic changes in the erectile tissue: minimal to marked fibrosis at the injection site and hypertrophy of smooth muscle in the non-injected area of the corpus.

Topical treatment of erectile dysfunction: randomised double blind placebo controlled trial of cream containing aminophylline, isosorbide dinitrate, and co-dergocrine mesylate

“…In addition, self injection is painful and stressful and may cause haematoma and infections. Furthermore, intracorporeal fibrosis, priapism, and systemic cardiovascular side effects may develop 9 10 11…”

Histopathological Change of Corpora cavernosa after Long-Term Intracavernous Injection

“…Abozeid et al [ 12] reported that increased sensitivity to papaverine injections was observed in 2 monkeys and that a lower dosage induced the same response after repeated use of drug. It was hypothesized that some changes happened in the nerve ending or a better re sponse was gained from hypertrophied smooth muscle cells.…”

Intracavernous pharmacotherapy for management of erectile dysfunction in spinal cord injury

“…Fibrosis of the corpus cavernosum has been reported with experimental papaverine injections in monkeys (Abozeid, 1987). There have been several case reports of fibrosis occurring in humans after varying periods of utilisation of intracavernous injections of both phentolamine and papaverine (Larsen, 1987;Hu, 1987).…”