title: An evaluation of the pharmacokinetics and pharmacodynamics of the histrelin implant for the palliative treatment of prostate cancer.
abstract: Seventeen patients with advanced prostate cancer were studied to evaluate the pharmacokinetics and pharmacodynamics of a hydrogel implant designed to deliver histrelin at a constant rate (50 microg/d) for 1 year. Serum histrelin levels were collected during the 52-week implantation period and after a second implant. Testosterone suppression was the primary pharmacodynamic endpoint, with treatment success defined as serum testosterone less than 50 ng/dL. The histrelin subdermal implant delivered constant histrelin levels, with mean serum histrelin of approximately 0.265 ng/mL over 52 weeks. At the end of 52 weeks, mean histrelin concentrations were 0.128 +/- 0.0652 ng/mL. Patients achieved chemical castration (testosterone less than 50 ng/mL) by week 4. In patients who had the first implant removed and received a new implant at the end of the first 52 weeks, testosterone suppression was not interrupted. The hydrogel implant provided consistent delivery of histrelin over 1 year and effectively suppressed testosterone in men with prostate cancer.
authors.affiliation: Atlantic Urological Associates, Daytona Beach, Florida, USA.
authors.forename: Martin K
authors.initials: MK
authors.lastname: Dineen
authors.forename: David S
authors.initials: DS
authors.lastname: Tierney
authors.forename: Petr
authors.initials: P
authors.lastname: Kuzma
authors.forename: Helen S
authors.initials: HS
authors.lastname: Pentikis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004343:Drug Implants; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology; D006801:Humans; D020100:Hydrogels; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D013739:Testosterone / Q000097:blood*
chemical_list: D004343:Drug Implants; D020100:Hydrogels; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D007986:Luteinizing Hormone; C029256:histrelin