Quinagolide reduces peritoneal endometriotic lesions
Last Updated: 2010-11-19 11:25:21 -0400 (Reuters Health)
By David Douglas
NEW YORK (Reuters Health) - A pilot study of hyperprolactinemic women with endometriosis shows that the dopamine receptor 2 agonist quinagolide reduces or eliminates peritoneal endometriotic lesions, Spanish researchers report in a November 8th online paper in Fertility and Sterility.
Dr. Antonio Pellicer told Reuters Health by email, "The study is the proof-of-concept that dopamine agonists reduce endometriosis lesions" and the first to show the effect of an anti-angiogenic drug on endometriosis.
Dr. Pellicer of the Valencia University School of Medicine and colleagues note that vascular endothelial growth factor (VEGF) is involved in growth of these lesions and animal studies have suggested that VEGF blockade can hinder the process. However, side effects preclude this approach in humans.
Another avenue is use of dopamine receptor 2 agonists, which have an acceptable safety profile and have been shown to inhibit angiogenesis via their effect on the VEGF 2 receptor.
To investigate the feasibility of thus using quinagolide, the researchers studied nine women who required their first surgical intervention because of severe endometriosis.
Four to six peritoneal red lesions were identified before surgery. One-half of the lesions were removed and the remaining one-half were labeled.
One week later, oral administration of quinagolide was begun at 25 mcg per day and reached 75 mcg per day over the course of 18 to 20 weeks. The remaining lesions were then excised.
Overall, 35% of the labeled lesions had vanished. In 2 patients all were gone completely and quinagolide induced a 69.5% reduction in the size of the remaining lesions in the other patients.
Histologic analysis showed tissue degeneration, which was supported by down-regulation of VEGF/VEGF 2 receptor, 3 proangiogenic cytokines and plasminogen activator inhibitor 1. This potent inhibitor of fibrinolysis was the most down-regulated gene.
The results are encouraging, but say the investigators, "Before adding this very promising type of medication to the armamentarium for the treatment of endometriosis, larger clinical trials need to be conducted to confirm our results and investigate in more depth its mechanism of action."
Nevertheless, added Dr. Pellicer, "dopamine agonists do not alter the menstrual cycle. Thus, women can become pregnant while treating endometriosis -- remember most endometriosis patients are infertile."
This, he concluded, is in contrast to "the available medications, which are based on an anti-estrogenic effect and cause anovulation."
SOURCE:http://link.reuters.com/vax26q
Fertil Steril 2010.
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