Description
Goserelin is an analog of luteinizing hormone-releasing hormone (LHRH) useful in the
treatment of malignancies responsive to hormonal manipulation. Administered
parenterally in a biodegradable depot, goserelin is reportedly as effective as orchidectomy
and oophorectomy in patients with advanced prostate carcinoma and pre-menopausal
breast cancer.
Chemical Properties
White or almost white powder.
Originator
ICI (United Kingdom)
Uses
Labelled Goserelin (G767500). Synthetic peptide agonist analog of LH-RH. Antineoplastic (hormonal).
Uses
Goserelin USP (Zoladex) is used to treat Prostatic carcinoma.
Uses
Labeled Goserelin, intended for use as an internal standard for the quantification of Goserelin by GC- or LC-mass spectrometry.
Definition
ChEBI: Goserelin is an organic molecular entity.
Manufacturing Process
(a) Solid Phase Preparation of Nonapeptide
The solid phase synthesis was carried out in automatic mode on an Applied
Biosystems 430A Peptide Synthesizer using Boc-Pro-OBzl-polystyrene resin
1% cross-linked with divinylbenzene (Peninsula Laboratories), 1.25 g, 0.38
meq/g though nominally 0.7 meq/g). The following protected amino acids
were converted to benzotriazolyl esters by reaction with HOBt (1-
hydroxybenzotriasole) and DIPC (di-isopropylcarbodiimide) in DMF
immediately before use. The protected amino acids were coupled in the
following sequence: Boc-Arg(HCl)-OH; Boc-Leu-OH; Fmoc-D-Ser(But)-OH;
Fmoc-Tyr(BrZ)-OH; Fmoc-Ser-OH; Fmoc-Trp-OH; Fmoc-His(Fmoc)-OH; PyrOH. The sequence of operations for the first two stages (using Boc-protectedamino acids) was: removal of Boc with 45% triflouroacetic acid in
dichloromethane;10% DIEA (diethyl amine)/DMF wash; coupling (2
equivalents of protected amino acid HOBt ester); removal of Boc as above.
The sequence of operations for the last six stages (using Fmoc-protectedamino acids) was: removal of Fmoc with 20% piperidine/DMF; 0.5 molar
HOBt/DMF wash; coupling (1 equivalent of protected amino acid HOBt ester).
All coupling reactions except that using Boc-Arg(HCl)-OH were of 1 hour
duration; the Boc-Arg(HCl)-OH one was of 2 hours duration. There was thus
obtained the nonapeptide-resin (1.7 g; 0.29 mmole peptide per g) with the
Tyr still protected by BrZ.
(b) Cleavage of Peptide From Resin
The peptide resin prepared above was treated with a 20-fold excess of
anhydrous hydrazine in DMF (20 ml) at laboratory temperature for 24 hours,
and the mixture was filtered and evaporated to dryness. This procedure also
removed the BrZ protecting group from the Tyr moeity. The residue was
purified by gel filtration on a column (LH 20 Sephadex) using a 20:1 v/v
mixture of water and acetic acid as eluant. There was thus obtained Pyr-HisTrp-Ser-Tyr-D-Ser(But)-Leu-Arg(H+)-Pro-NH-NH2. The structure of which was
confirmed by amino acid analysis and mass spectroscopy.
(c) Preparation of Goserelin
A solution of potassium cyanate (11 mg) in water (1.36 ml) was added
portionwise during 1 hour to a solution of the above hydrazide (118 mg) in a
20:1 v/v mixture of water and acetic acid (10 ml). The mixture was freezedried and the residue was purified by reverse-phase column chromatography
(Dynamax 60 ANG, C18, 1 inch diameter) using a gradient of 10% to 40% by
volume of acetonitrile in water containing 0.1% trifluoroacetic acid. There was
thus obtained goserelin (100 mg, 25% yield overall), the structure of which
was confirmed by mass spectroscopy.
brand name
Zoladex (Zeneca).
Therapeutic Function
Antineoplastic, Antitumor
Clinical Use
Synthetic decapeptide analogue of LHRH:
Treatment of advanced prostate cancer, breast cancer,
endometriosis and endometrial thinning and uterine
fibroids
Side effects
Hot flashes (flushing), dizziness, headache, increased sweating, decreased sexual interest/ability, trouble sleeping, nausea, change in breast size, vaginal dryness, or hair loss may occur. Pain, bruising, bleeding, redness, or swelling at the injection site may also occur.
This medication may rarely make your blood sugar rise, which can cause or worsen diabetes.
Serious side effects including: symptoms of a heart attack (such as chest/jaw/left arm pain, shortness of breath, unusual sweating), signs of a stroke (such as weakness on one side of the body, trouble speaking, sudden vision changes, confusion), fast/irregular heartbeat, severe dizziness, fainting.
In men using this medication for prostate cancer, a rare but very serious urinary blockage problem or spinal cord problem (compression) can occur, especially during the first month of treatment.
Drug interactions
Goserelin may be given on its own or is often combined with another hormone therapy such as tamoxifen or drugs known as aromatase inhibitors (anastrozole, exemestane and letrozole).
The risk or severity of QTc prolongation can be increased when Goserelin is combined with Clozapine. The risk or severity of methemoglobinemia can be increased when Goserelin is combined with Cocaine.
Metabolism
Metabolised by tissue peptidases and is excreted in urine
and bile as unchanged drug and metabolites.
Description
Goserelin contains 10 amino acids Glu1-His2-Trp3-Ser4-Tyr5-D-Ser(tBu)6-Leu7-Arg8-Pro9-AzGly10-NH2 and having a molecular weight of 1269.43 Dalton.
Background
Goserelin is a hormone similar to the one normally released from the hypothalamus gland in the brain (GnRH super-agonist). It is used to treat for prostate and breast cancer.
Goserelin decreases the amount of estrogen and testosterone by this treating endometriosis and cancer of the breast, and can help thin the uterus lining before surgery. Goserelin prevents the growth of tissue associated with endometriosis.
Reducing the amount of testosterone is one way of treating prostate cancer.
