Elagolix Sodium: Novel GnRH Antagonist for the Treatment of Endometriosis

Endometriosis is a category of lesions and fibroids which occur in the innermost lining of the uterus that is the endometrial layer and spreads to the other parts of the neighboring tissues. It is characterized by inflammation, pelvic pain, menstrual bleeding, and Dysmenorrhea. Endometriosis exists in 3 forms based on its spreadability. i.) superficial peritoneal lesions ii.) deep infiltrating lesion and iii.) cyst. Traditional treatments involve are NSAIDS, Oral contraceptives, Aromatase inhibitors, and GnRH agonists. Elagolix emerges out to be the latest potent drug that acts by inhibiting the GnRH receptor. Unlike other allopathy medicine, it is not an asymptomatic pain reliever but acts on the root cause of the disease. FDA has approved it for specific treatment of endometriosis in July 2018. It is believed that endometriosis occurs by an increase in the production of estrogen. Elagolix competitively binds to the GnRH receptors and prevents the binding of the Gonadotropin hormone flowing through blood capillaries from the Hypothalamus to the pituitary gland and thereby stops the formation of Oestrogen in the reproductive system which ultimately ceases in the proliferation of endometrial layers and tissue spread. In estrogen biosynthesis, the aromatase P450 enzyme plays a vital role. Elagolix belongs to BCS class III and available in the oral dosage form of 150, 200mg. It is rapidly absorbed and Cmax reaches within 1hour. The plasma protein binding is 80%. In this review, various aspects related to Elagolix sodium have been summarised, which include pathophysiology, Mode of Action, Structure-activity relationship, Pharmacokinetics, pharmacodynamics, and clinical studies with minimal side effects.