NOAH Compendium

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Date: Sunday, May 22, 2022 1:25

Release 2.90
Ovarelin® 50 µg/ml, solution for injection for cattle
Species: Cattle
Therapeutic indication: Pharmaceuticals: Hormones and therapeutically related products: GnRH products
Active ingredient: Gonadorelin
Product:Ovarelin® 50 µg/ml, solution for injection for cattle
Product index: Ovarelin
Cattle - milk: Zero hours
Cattle - meat: Zero days
Qualitative and quantitative composition
Composition for 1 ml:
Active substance:
Gonadorelin (as diacetate tetrahydrate) 50.0 µg
Benzyl alcohol (E1519) 15.0 mg
For the full list of excipients, see Pharmaceutical particulars.
Pharmaceutical form
Solution for injection. Clear colourless solution.
Clinical particulars
Target species
Cattle: cows, heifers.
Indications for use, specifying the target species
Induction and synchronisation of oestrus and ovulation in combination with prostaglandin F2α (PGF) or analogue with or without progesterone as part of Fixed Time Artificial Insemination (FTAI) protocols.
Treatment of delayed ovulation (repeat breeding).
A repeat breeder cow or heifer is generally defined as an animal that has been inseminated at least 2 or often 3 times without becoming pregnant, despite having regular normal œstrus cycles (every 18-24 days), normal œstrus behaviour and no clinical abnormalities of the reproductive tract.
Do not use in cases of hypersensitivity to the active substance or to any of the excipients.
Special warnings for each target species
The response of dairy cows to synchronisation protocols may be influenced by the physiological state at the time of treatment, which includes age of the cow, body condition and interval from calving.
Responses to treatment are not uniform either across herds or across cows within herds.
Where a period of progesterone treatment is included in the protocol, the percentage of cows displaying oestrus within a given period is usually greater than in untreated cows and the subsequent luteal phase is of normal duration.
Special precautions for use
Special precautions for use in animals
Not applicable.
Special precautions to be taken by the person administering the veterinary medicinal product to animals
Gonadorelin is a Gonadotropin Releasing Hormone (GnRH) analogue which stimulates the release of sex hormones. The effects of accidental exposure to GnRH analogues in pregnant women or in women with normal reproductive cycles are unknown; therefore it is recommended that pregnant women should not administer the product, and that women of child-bearing age should administer the product with caution. Care should be taken when handling the product to avoid self-injection. In cases of accidental self-injection, seek medical advice immediately and show the package leaflet or the label to the physician.
Care should be taken to avoid skin and eye contact. In cases of skin contact, rinse immediately and thoroughly with water as GnRH analogues can be absorbed through the skin. In cases of accidental contact with eyes, rinse thoroughly with plenty of water. People with known hypersensitivity (allergy) to GnRH analogues should avoid contact with the veterinary medicinal product.
Adverse reactions (frequency and seriousness)
Use during pregnancy, lactation or lay
Laboratory studies in rats and rabbits have not produced any evidence of a teratogenic or embryotoxic effects.
Observations in pregnant cows receiving the product in early pregnancy have not shown evidence of negative effects on bovine embryos.
Inadvertent administration to a pregnant animal is unlikely to result in adverse effects.
Interaction with other medicinal products and other forms of interaction
None known.
Amounts to be administered and administration route
Intramuscular use.
100 µg of gonadorelin (as diacetate) per animal in a single injection. i.e. 2 ml of the product per animal.
Judgement on the protocol to be used should be made by the veterinarian responsible for treatment, on the basis of the treatment objectives of the individual herd or cow. The following protocols have been evaluated and could be used:
Induction and synchronisation of oestrus and ovulation in combination with a prostaglandin F2α (PGF2α) or analogue:
Day 0: First injection of gonadorelin (2 ml of the product)
Day 7: Injection of prostaglandin (PGF2 α) or analogue
Day 9: Second injection of gonadorelin (2 ml of the product) should be done.
The animal should be inseminated within 16-20 hours after the last injection of the product or at observed oestrus if sooner.
Induction and synchronisation of oestrus and ovulation in combination with a prostaglandin F2α (PGF2α) or analogue and a progesterone releasing intravaginal device:
The following FTAI protocols have been commonly reported in the literature:
Insert progesterone releasing intravaginal device for 7 days.
Inject gonadorelin (2 ml of the product) at the progesterone device insertion.
Inject a prostaglandin (PGF2 α) or analogue 24 hours prior to device removal
FTAI 56 hours after removal of the device, or
Inject gonadorelin (2 ml of the product) 36 hours after progesterone releasing intravaginal device removal and FTAI 16 to 20 hours later.
Treatment of delayed ovulation (repeat-breeding):
GnRH is injected during oestrus.
To improve the pregnancy rates, the following timing of injection and insemination should be followed:
injection should be performed between 4 and 10 hours after oestrus detection
an interval of at least 2 hours between the injection of GnRH and artificial insemination is recommended
artificial insemination should be carried out in accordance with the usual field recommendations, i.e., 12 to 24 hours after oestrus detection.
Overdose (symptoms, emergency procedures, antidotes), if necessary
After single administration of up to 5 times recommended dose or one to three daily administrations of recommended dose, no measurable signs of either local or general clinical intolerance are observed.
Withdrawal periods
Meat and offal: zero days
Milk: zero hours
Pharmacological particulars
Pharmacotherapeutic group: Gonadotropin-releasing hormones. ATCvet code: QH01CA01
Pharmacodynamic properties
Gonadorelin (as diacetate) is a synthetic hormone physiologically and chemically identical to the Gonadotropin Releasing Hormone (GnRH) synthesized in mammalian species.
Gonadorelin stimulates the synthesis and release of the pituitary gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH). Its action is mediated by a specific plasma membrane receptor. Only 20% GnRH receptor occupancy is required to induce 80% of the maximum biological response. The binding of GnRH to its receptor activates protein kinase C (PKC) and also mitogen-activated protein kinase (MAPK) cascades which provide an important link for the transmission of signals from the cell surface to the nucleus allowing synthesis of the gonadotropin hormones.
In repeat breeding animals, one of the most prominent findings is the delayed and smaller preovulatory LH surge leading to delayed ovulation. Injection of GnRH during oestrus increases the spontaneous LH peak and prevents delay in ovulation in repeat breeding animals.
Pharmacokinetic particulars
After intramuscular administration of 100 µg of gonadorelin (as diacetate) to the animal, absorption of GnRH is rapid. The maximum concentration (Cmax) of 120.0 ± 34.2 ng / litre is obtained after 15 min (Tmax). Concentrations of GnRH decreased rapidly in plasma.
The absolute bioavailability of gonadorelin (IM versus IV) was estimated to be around 89%.
24 hours after intramuscular administration of 100µg of radiolabelled gonadorelin (as diacetate), the greatest amounts of radioactivity in tissues were measured in the main organs of excretion: liver, kidney and lungs.
8 or 24 hours after the administration, gonadorelin shows an extensive plasma protein binding of 73%.
Gonadorelin is a naturally occurring peptide which is rapidly broken down into inactive metabolites.
After intramuscular administration of gonadorelin to the dairy cow, the principal excretion route is milk followed by urine and faeces. A high percentage of the administered dose is excreted as carbon dioxide in expired air.
Pharmaceutical particulars
List of excipients
Benzyl alcohol (E1519), Potassium dihydrogen phosphate, Dipotassium phosphate, Sodium chloride, Water for injections
Major incompatibilities
In the absence of compatibility studies, this veterinary medicinal product must not be mixed with other veterinary medicinal products.
Shelf life
Shelf-life of the veterinary medicinal product as packaged for sale: 2 years.
Shelf-life after first opening the immediate packaging: 28 days.
Special precautions for storage
Do not store above 25°C.
Keep the container in the outer carton in order to protect from light.
Nature and composition of immediate packaging
Material of the primary container:
Colourless glass vial type I (4 ml).
Colourless glass vial type II (10, 20 and 50 ml).
Chlorobutyl stopper.
Pack sizes:
Box containing 1 glass vial of 4 ml
Box containing 1 glass vial of 10 ml
Box containing 1 glass vial of 20 ml
Box containing 1 glass vial of 50 ml
Not all pack sizes may be marketed.
Special precautions for the disposal of unused veterinary medicinal product or waste materials derived from the use of such products
Any unused veterinary medicinal product or waste materials derived from such veterinary medicinal products should be disposed of in accordance with local requirements.
Marketing Authorisation Holder (if different from distributor)
Marketing Authorisation Number
UK: Vm 15052/4022
Significant changes
Date of the first authorisation or date of renewal
28 April 2006
Date of revision of the text
April 2019
Any other information
Legal category
Legal category: POM-V
GTIN description:Ovarelin 10 ml
GTIN description:Ovarelin 20 ml