Factrel (Canada)This page contains information on Factrel for veterinary use.
The information provided typically includes the following:
- Factrel Indications
- Warnings and cautions for Factrel
- Direction and dosage information for Factrel
FactrelThis treatment applies to the following species:
GONADORELIN FOR INJECTION, USP
VETERINARY USE ONLY
FACTREL (gonadorelin for injection, USP) is a sterile solution of synthetic luteinizing hormone/releasing hormone (LRH) intended for intramuscular administration.
Each mL of sterile solution contains gonadorelin (as hydrochloride salt), 50 µg.
Preservatives: Benzyl alcohol 2% w/v.
FACTREL’s (gonadorelin hydrochloride) chemical name is 5-oxo-L-propyl-L-histidyl- L-tryptophyl-L-seryl-L-tyrosyl-glycyl-L-leucyl-L-arginyl-L-prolyl-glycinamide hydrochloride.
Its molecular formula is C55H75H17O13 X HCl (X = 1 ~ 2), and it has a molecular weight of 1219 to 1255 depending on its hydrochloric acid content. It is structurally identical to the natural Luteinizing Hormone/Releasing Hormone (LRH) isolated from porcine or ovine hypothalami. The hydrochloride salt of gonadorelin used in FACTREL is a water-soluble white powder. It is synthesized by the classical solution method, and is virtually free of extraneous peptides or amino acids.
Gonadorelin (GnRH) induces ovulation when administered subcutaneously on the day of proestrus. It acts by augmentation of anterior pituitary secretion of the gonadotropins, Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH). Gonadorelin’s capacity to cause secretion of LH was found to be equal to that of LH/FSH-RH of natural origin.
In the treatment of cystic ovaries, FACTREL was demonstrated to be safe and effective at a clinical dose of 100 µg. Clinically it has been demonstrated that breeder cows treated with GnRH, at their third or greater services, showed a 51.1% conception rate, as opposed to a 43.2% conception rate for the control group.
As an aid in the treatment of cystic ovaries in cattle. For use in repeat breeder dairy cows on or at the time of their third or greater service.
Factrel Dosage And Administration
Cystic Ovaries: 2 mL (100 µg) as a single intramuscular injection.
Repeat Breeders: 2 mL (100 µg) to be administered intramuscularly as a single injection on or at the time of cow’s third or greater service.
Treated animals must not be slaughtered for use in food for at least 7 days after the latest treatment with this drug.
No milk withholding time is required when used according to the label.
Keep out of reach of children.
Gonadorelin did not elicit any signs of toxicity and was not lethal after intravenous administration of single doses of 100 mg/kg in mice and of single doses of 150 mg/kg in rats. Following 28 consecutive days IV administration in mature rats at doses of 5, 25 and 50 µg/kg/day secondary pharmacology or hormonal changes were observed in treated males. These changes included decreased seminal vesicle weight (all doses), decreased body weight and prostatic weight (25 µg/kg or greater). These organ and body weight changes are regarded as secondary effects resulting from gonadotrophin release and the feed-back mechanism to high circulating levels of LH. There were no drug-related histopathologic alterations of seminal vesicle or prostate. In treated females, body and organ weights were comparable to the controls and there were no drug-related histopathologic alterations. In monkeys receiving daily doses of 500 µg of gonadorelin for 28 days and in monkeys receiving either 4, 20 or 100 µg/kg/day from day 8 to day 15 of each animal’s cycle, survival body weight, food consumption, clinical laboratory parameters, organ weights, gross and microscopic observations were not affected. No biologically significant changes in clinical chemistry parameters were observed.
Teratology studies were carried out in pregnant female mice, rats (two strains) and rabbits. Daily doses of gonadorelin up to 100 µg/kg were administered subcutaneously on days 6 through 15 of pregnancy in mice and rats, and on days 6 through 18 of gestation in rabbits. The administration of the compound, at doses of 100 µg/kg or less, did not produce any toxic effects in the dams or fetuses of the species tested.
Refrigerate, store at a temperature between 2° and 7°C.
FACTREL is available in 20 and 50 mL vial sizes.
1. Banik, U.K. and C. Revesz: Biological activities of synthetic LH-RH (AY-24,031) in rats. Ayerst Research Laboratories, Pharmacology Department Research Report 24,031-04.
2. Revesz, C. and U.K. Banik: Biological testing of AY-24,031, synthetic LH-RH in hamsters. Ayerst Research Laboratories, Pharmacology Department Research Report 24,031-01.
3. Revesz, C. and J. Smyth: Reversal of the persistent estrus syndrome in rats by AY-24,031, the synthetic LH-releasing Factor. Ayerst Research Laboratories, Pharmacology Department Research Report 24, 031-06.
4. Schally, A.V., A.J. Kastin and A. Arimura: The hypothalamus and reproduction. Am. J. Obstet. Gynecol. 114:423-442, 1972.
5. Schally, A.V., A. Arimura, W.H. Carter and T.W. Redding: Luteinizing hormone-releasing hormone (LH-RH) activity of some synthetic polypeptides. I. Fragments shorter than decapeptide. Biochem. Biophys. Res. Comm. 48:366, 1972.
6. Hirsch, M.A.: Introduction of luteinizing hormone (LH) secretion by AY-24,031 in estrogen-progesterone-treated ovariectomized rats. Ayerst Research Laboratories, Department of Endocrinology and Immunochemistry Research Report AY-24,031-16.
7. Vavra, I. and M.P. Charest: General and cardiovascular acute tolerance studies on AY-24,031. Ayerst Research Laboratories, Pharmacology Department Research Report 24,031-02.
8. Hemm, R.D., L. Arslanoglou and L. Authier: AY-24,031: Twenty-eight day intravenous toxicity study in the rat. Ayerst Research Laboratories, Animal Health Division Research Report 24,031-03.
9. Martini, L., M. Matta and F. Faschini: The Hypothalamus Academic Press Inc., New York (1970).
10. Hemm, R.D. and L. Authier: AY-24,031: Twenty-eight day subcutaneous toxicity study in the monkey. Ayerst Research Laboratories, Animal Health Division Research Report 24,031-13.
11. Hemm, R.D. and L. Authier: AY-24,031: One cycle subcutaneous toxicity study in the monkey. Ayerst Research Laboratories, Animal Health Division Research Report 24,031-05.
12. Hemm, R.D. and L. Authier: AY-24,031: Three cycle subcutaneous toxicity study in the female monkey. Ayerst Research Laboratories, Animal Health Division Research Report 24,031-14.
13. Hemm, R.D. and L. Arslanoglou: AY-24,031: Evaluation of embryotoxic and teratologic potential in the mouse, Segment II of the “FDA Guidelines for Reproductive Studies”. Ayerst Research Laboratories, Animal Health Division Research Report 24,031-07.
14. Hemm, R.D. and L. Arslanoglou: AY-24,031: Evaluation of embryotoxic and teratogenic potential in the Long Evans rat, Segment II of the “FDA Guidelines for Reproductive Studies”. Ayerst Research Laboratories, Animal Health Division Research Report 24,031-10.
15. Hemm, R.D. and L. Arslanoglou: AY-24,031: Evaluation of embryotoxic and teratogenic potential in the Charles River rat, Segment II of the “FDA Guidelines for Reproductive Studies”. Ayerst Research Laboratories, Animal Health Division Research Report 24,031-08.
16. Hemm, R.D. and L. Arslanoglou: AY-24,031: Evaluation of embryotoxic and teratogenic potential in the rabbit, Segment II of the “FDA Guidelines for Reproductive Studies”. Ayerst Research Laboratories, Animal Health Division Research Report 24,031-09.
17. Ayerst clinical report: Evaluation of clinical efficacy of GnRH as treatment for ovarian cysts in dairy cattle (protocols BW-83-1, BA-83-3). Data on file, Wyeth.
18. Leslie, K.E. and Kelton, D.F.: A study of the relationship of Gonadotrophin releasing hormone administered at breeding to herd, reproductive performance. Data on file, Ayerst Laboratories.
© Pfizer Canada Inc.
Pfizer Animal Health, Pfizer Canada Inc., Kirkland QC H9J 2M5
April 26, 2011 Edited
NAC No.: 1198370.3
16,740 TRANS-CANADA HIGHWAY, KIRKLAND, QC, H9H 4M7
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