What is the mechanism of action (MOA) of LHRH agonists?

LHRH agonists, also known as GnRH agonists, function through a specific mechanism that first stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland, leading to a temporary increase in the production of sex hormones like testosterone and estrogen. This initial surge is often referred to as a "flare" effect. However, prolonged exposure to LHRH agonists causes a downregulation of GnRH receptors, resulting in decreased secretion of LH and FSH over time. As a consequence, this ultimately leads to a reduction in the levels of testosterone and estrogen in the body, which can be beneficial in the treatment of hormone-sensitive conditions, such as certain types of prostate and breast cancer.

This mechanism of action is particularly important when considering treatment strategies for hormone-responsive tumors, as it highlights the dual phases of action of LHRH agonists: the initial stimulation followed by a long-term suppression of hormone production. Thus, understanding this mechanism is crucial for healthcare providers when developing treatment plans involving hormone modulation.