Histrelin is a gonadotropin-releasing hormone (GnRH) agonist that acts as a potent inhibitor of gonadotropin when administered as an implant delivering continuous therapeutic doses. This drug is a synthetic analog of naturally occurring GnRH with a higher potency. Histrelin implants are non-biodegradable, diffusion-controlled, hydrogel polymer reservoirs containing histrelin acetate that need to be replaced every 52 semanas.
Initially, histrelin implants were developed to reduce testosterone to castration levels in patients with advanced prostate cancer.The Vantas product was approved by the FDA in October 2004 for the palliative treatment of this condition.Vantas was later discontinued by Endo Pharmaceuticals Inc. on September 21, 2021.
Histrelin inhibits gonadotropin secretion through the reversible down-regulation of gonadotropin-releasing hormone (GnRH) receptors in the pituitary gland and desensitization of the pituitary gonadotropes.In pediatric patients with central precocious puberty (CPP), long-term treatment with histrelin acetate suppresses the luteinizing hormone (ES) response to GnRH, causing LH levels to decrease to prepubertal levels within one month of treatment.This reduces ovarian and testicular steroidogenesis and slows down linear growth velocity, improving the chance of attaining predicted adult height. When given orally, histrelin acetate is not active.
