GnRH

Abarelix (30 and 300 µg/mL) causes significantly increased histamine release. Abarelix is the firstGnRH antagonist to be developed, and can produce rapid and sustained decreases in testosterone to castrate levels without the need for co-administration of an antiandrogen, and with a very low complication rate in the short term. Abarelix demonstrates to promptly and substantially reduce follicle-stimulating hormone levels to lower than LHRH agonist. Abarelix does not cause a surge in serum testosterone that can precipitate a flare phenomenon or worsening of disease, particularly dangerous for patients with metastatic, symptomatic disease, and produces medical castration more quickly.