Gonadotropin Releasing Hormone Agonists and Antagonists

The most common form of ADT involves suppression of the pituitary with GnRH agonists. GnRH agonists cause an initial surge in levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), followed by inhibition of gonadotropin release (see Chapter 55). One important side effect, a transient flare of disease due to the initial gonadotropin surge, can be avoided by temporary (2-4 weeks) administration of AR blockers or by the use of GnRH antagonists (see below).

Complete androgen blockade (CAB) refers to combination therapy with androgen-receptor blockers and GnRH agonists. However, the advantages of long-term CAB over GnRH agonists alone are questionable.

Treatment with GnRH antagonists rapidly reduces serum testosterone levels, without the transient initial increase observed after GnRH agonists. Abarelix (plenaxis) effectively reduces serum testosterone to castrate levels within a week in most men. Other than avoidance of the initial flare, GnRH antagonist therapy offers no advantage compared with GnRH agonists, and GnRH antagonists for prostate cancer are available only in the 1-month depot formulation.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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