The Gonadotropin-releasing hormone antagonist (GnRH antagonist) is a drug used for treating many chronic diseases. It is actually a modified version of the naturally occurring gonadotropin-releasing hormone (GnRH) secreted by the pituitary gland. It is generally made of peptide molecules which, in turn, are created from artificially-produced amino acids. There are, however, a few non-peptide compounds as well.
Mode of action
The GnRH antagonists are known for inhibiting the pituitary gland from the secretion of follicle stimulating hormone (FSH) and luteinising hormone (LH). The blockage of LH rapidly suppresses the release of testosterone and estrogen in men and women, respectively.
- Endometriosis, a painful condition characterized by the appearance of the endometrial tissue outside the uterus, can be treated by estrogen suppression, and this can be achieved by administering GnRH antagonists.
- In men with prostate cancer, the testosterone circulating in the blood aggravates the tumor. The GnRH antagonists provide quick suppression of this hormone, and as a result, the levels of PSA (prostate-specific antigen) in the subject’s blood come down. This is extremely helpful in treating patients with advanced stages of prostate cancer, where a rapid suppression of the disease is required.
- Apart from disease control, the GnRH antagonists are used in the In-vitro Fertilization cycle (IVF) to stop ovulation. This allows the physicians to control the growth of eggs, which will be collected at the right time thereby increasing the procedure’s chances of success.
- The GnRH antagonists are also being used in the treatment of hormone-sensitive breast and ovarian cancers. In a recent test conducted on 17 patients, six of them experienced disease stabilization for one year. Apart from treating cancers, these drugs are known to cure uterine fibroids.
- In men, these compounds are being studied for their effectiveness in curing benign prostatic hyperplasia.
Mode of administering:
The most commonly used GnRH-antagonist drugs include Suprefact, Zoladex, Synarel and Lupron. They are typically administered either by a subcutaneous or intramuscular injection or through a nasal spray. Depending on the treatment plan, patients need to take daily injections over several days or a single injection every few days, as directed by their physician.
Are there any potential side effects?
Just like all hormonal treatments, the GnRH antagonists are associated with common side effects such as headaches, weight gain, nausea and hot flushes. When used as part of fertility treatment, they may cause mild abdominal pain and hyperstimulation of the ovaries, in rare cases. Also, when administered through a subcutaneous injection, they may cause injection-site reactions. However, these side effects are rare and can be controlled by using medications under a doctor’s supervision.
Please note that the GnRH antagonists are administered as part of a hormonal therapy, so they should be administered only with the consent of an endocrinologist or any other qualified doctor. This greatly minimizes the risk of side effects and proliferates the success rate of the treatment. With the huge amount research being done on the benefits gonadotropin-releasing hormone antagonist, there is no doubt that this compound will be used for treating more number of diseases in the near future.