Title:The Skeletal Effects of Gonadotropin-Releasing Hormone Antagonists: A Concise Review
VOLUME: 21
Author(s):Nur-Vaizura Mohamad, Ima-Nirwana Soelaiman and Kok-Yong Chin*
Affiliation:Department of Pharmacology, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Department of Pharmacology, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Department of Pharmacology, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur
Keywords:Bone mineral density, estrogen, fracture, osteoporosis, sex hormones, testosterone.
Abstract:Prolonged treatment with gonadotropin-releasing hormone (GnRH) agonists is known to induce bone loss among
prostate cancer patients. However, evidence on the skeletal effects of GnRH antagonists is relatively less well-known. This
review aims to examine the effects of GnRH antagonists on bone health. GnRH antagonists are an effective treatment for
hormone-dependent conditions, such as advanced prostate cancer and endometriosis. They induce a competitive and
reversible GnRH-receptor blockage, thereby suppressing the release of gonadotropins and sex hormones. The sex hormone
ablation results in undesirable side effects, including accelerated bone loss. In animal studies, treatment with GnRH
antagonists is reported to cause deterioration of bone microstructure. Human clinical trials revealed significant bone loss at
the spine, hip and femur in patients treated with GnRH antagonists. Thus, osteoporosis and the resultant fragility fractures
pose a significant impact on health and quality of life of GnRH antagonist users. Thus, early preventive measures of bone
loss are critical in preventing fractures and its associated morbidity in these patients.