Goserelin

Goserelin

File:Goserelin ball-and-stick.png
Systematic (IUPAC) name
N-(21-((1H-indol-3-yl)methyl)-1,1-diamino-12-(tert-butoxymethyl)-6-(2-(2-carbamoylhydrazinecarbonyl)cyclopentanecarbonyl)-15-(4-hydroxybenzyl)-18-(hydroxymethyl)-25-(1H-imidazol-5-yl)-9-isobutyl-8,11,14,17,20,23-hexaoxo-2,7,10,13,16,19,22-heptaazapentacos-1-en-24-yl)-5-oxopyrrolidine-2-carboxamide
Clinical data
Trade names	Zoladex
AHFS/Drugs.com	monograph
MedlinePlus	a601002
Pregnancy category	D (3.6mg) / X (10.8mg) (USA)
Legal status	℞ (Prescription only)
Routes of administration	implant
Pharmacokinetic data
Protein binding	27.3%
Biological half-life	4-5 hours
Excretion	hepatic
Identifiers
CAS Number	65807-02-5 Y
ATC code	L02AE03 (WHO)
PubChem	CID: 5311128
IUPHAR/BPS	3879
DrugBank	DB00014 Y
ChemSpider	4470656 Y
UNII	0F65R8P09N Y
KEGG	D04405 Y
ChEBI	CHEBI:5523
ChEMBL	CHEMBL1201247 N
Synonyms	D-Ser(But)6Azgly10LHRH
Chemical data
Formula	C59H84N18O14
Molecular mass	1269.410 g/mol
SMILES CC(C)C[C@H](NC(=O)[C@@H](COC(C)(C)C)NC(=O)[C@H](CC1=CC=C(O)C=C1)NC(=O)[C@H](CO)NC(=O)[C@H](CC1=CNC2=CC=CC=C12)NC(=O)[C@H](CC1=CN=CN1)NC(=O)[C@@H]1CCC(=O)N1)C(=O)N[C@@H](CCCN=C(N)N)C(=O)N1CCC[C@H]1C(=O)NNC(N)=O
InChI InChI=1S/C59H84N18O14/c1-31(2)22-40(49(82)68-39(12-8-20-64-57(60)61)56(89)77-21-9-13-46(77)55(88)75-76-58(62)90)69-54(87)45(29-91-59(3,4)5)74-50(83)41(23-32-14-16-35(79)17-15-32)70-53(86)44(28-78)73-51(84)42(24-33-26-65-37-11-7-6-10-36(33)37)71-52(85)43(25-34-27-63-30-66-34)72-48(81)38-18-19-47(80)67-38/h6-7,10-11,14-17,26-27,30-31,38-46,65,78-79H,8-9,12-13,18-25,28-29H2,1-5H3,(H,63,66)(H,67,80)(H,68,82)(H,69,87)(H,70,86)(H,71,85)(H,72,81)(H,73,84)(H,74,83)(H,75,88)(H4,60,61,64)(H3,62,76,90)/t38-,39-,40-,41-,42-,43-,44-,45+,46-/m0/s1 Y Key:BLCLNMBMMGCOAS-URPVMXJPSA-N Y=  Y
NY (what is this?)  (verify)

Goserelin acetate (trade name Zoladex, by AstraZeneca) is a drug used to suppress production of the sex hormones (testosterone and estrogen), particularly in the treatment of breast and prostate cancer. It is an injectable gonadotropin releasing hormone superagonist (GnRH agonist), also known as a luteinizing hormone releasing hormone (LHRH) agonist. Structurally, it is a decapeptide.

Goserelin acetate stimulates the production of the sex hormones testosterone and estrogen in a non-pulsatile (non-physiological) manner. This causes the disruption of the endogenous hormonal feedback systems, resulting in the down-regulation of testosterone and estrogen production.

Zoladex was approved by the U.S. Food and Drug Administration in 1989 for treatment of prostate cancer. It is now widely used by transgender people who wish to falsify their sex. Sales to this market represent a growing source of profit.

Pharmacokinetics

Goserelin is a synthetic analogue of a naturally occurring luteinizing-hormone releasing hormone (LHRH). Bioavailability is almost complete. Goserelin is poorly protein bound and has a serum elimination half-life of two to four hours in patients with normal renal function. The half-life increases with patients with impaired renal function. There is no significant change in pharmacokinetics in subjects with liver failure. After administration, peak serum concentrations are reached in about two hours. It rapidly binds to the LHRH receptor cells in the pituitary gland thus leading to an initial increase in production of luteinizing hormone and thus leading to an initial increase in the production of corresponding sex hormones. This initial flare may be treated by co-prescribing/co-administering an androgen receptor antagonist such as Bicalutamide (Casodex). Eventually, after a period of about 14–21 days, production of LH is greatly reduced due to receptor downregulation, and sex hormones are generally reduced to castrate levels.

Indications

File:Implantsyringe.JPG

10.8mg implant syringe

Goserelin Acetate is used to treat hormone-sensitive cancers of the breast (in pre- and peri- menopausal women) and prostate, and some benign gynaecological disorders (endometriosis, uterine fibroids and endometrial thinning). In addition, goserelin is used in assisted reproduction and in the treatment of precocious puberty.

The drug is now also used by male-to-female transsexuals. This is not a medical use and it can have severe side effects (see below). Zoladex is the most popular anti-androgen drug in some countries, such as the UK. It is available as a 1-month depot and a long-acting 3-month depot.

Side effects

Goserelin Acetate may cause a temporary increase in bone pain and symptoms of prostatic cancer during the first few weeks of treatment. This is known as the tumour flare effect, and is the result of an initial increase in luteinizing hormone production, before the receptors are desensitised and hormonal production is inhibited. The symptoms will disappear, with hormonal inhibition. It is therefore advisable to co-treat with an antiandrogen during the first 2–3 weeks of Goserelin treatment, particularly in patients with pre-existing bone symptoms. Goserelin may cause bone pain, hot flushes, headache, stomach upset, depression, difficulty urinating (isolated cases), weight gain, swelling and tenderness of breasts (infrequent), decreased erections and reduced sexual desire. Bone pain can be managed symptomatically, and erectile dysfunction can be treated by Levitra (Vardenafil) or other similar oral therapies, although they will not treat the reduced sexual desire.

External links

• One man's experience of prostate cancer treatment using goserelin - BBC News