Dear Bovine Veterinarian:
In May, the U.S. Food and Drug Administration (FDA) issued a letter announcing the approval of GONAbreed (gonadorelin acetate). FDA would like to announce the approval of a second gonadorelin product, FACTREL Injection (gonadorelin hydrochloride), for estrous synchronization in lactating dairy cows. In combination with LUTALYSE (dinoprost tromethamine), FACTREL can be used to synchronize estrous cycles to allow fixed-time artificial insemination in lactating dairy cows.
Drug Information
| Factrel Injection | |
|---|---|
| Manufacturer | Zoetis Inc. |
| Application Type | New Animal Drug Application (NADA) |
| Application Number | 139-237 |
| New Indication | For use with LUTALYSE (dinoprost tromethamine) Sterile Solution to synchronize estrous cycles to allow fixed-time artificial insemination in lactating dairy cows. (FACTREL is already approved for the treatment of ovarian follicular cysts in cattle.) |
| Active Ingredient | Gonadorelin hydrochloride |
| Concentration | 50 mcg gonadorelin (as gonadorelin hydrochloride)/mL |
| How Supplied | 20 mL multi-dose vials |
| Dispensing Status | Prescription |
| Clinical Pharmacology |
Gonadorelin is the gonadotropin releasing hormone (GnRH) which is produced by the hypothalamus and causes the release of the gonadotropin luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary. FACTREL is a sterile solution of synthetic gonadorelin and has the identical amino acid sequence as endogenous gonadorelin. |
Please see the Freedom of Information Summary for FACTREL.
Benefits of FDA Approval
FDA rigorously evaluates an animal drug before approving it. As part of the approval process, the drug company must prove to FDA that:
- The drug is safe and effective for a specific use in a specific animal species;
- The manufacturing process is adequate to preserve the drug’s identity, strength, quality, and purity; and
- The drug’s labeling is truthful and non-misleading.
For a drug to be used in food-producing animals, FDA’s approval process also ensures that food products, such as milk and beef, from treated animals are safe for people to eat.
FDA’s role does not stop after the agency approves an animal drug. As long as the drug company markets the animal drug, the agency continues to monitor:
- The drug’s safety and effectiveness. Sometimes, the agency’s post-approval monitoring uncovers safety and effectiveness issues that were unknown at the time of approval;
- The manufacturing process to ensure quality and consistency are maintained; and
- The drug’s labeling to make sure the information remains truthful and non-misleading
Other Gonadorelin Products
Six gonadorelin (GnRH) products are FDA-approved to treat cystic ovaries in dairy cows. Of these six products, only FACTREL and GONAbreed are also FDA-approved for use in combination with another drug for synchronizing estrous cycles in lactating dairy cows.
FDA-approved GnRH Products for Use with Another Drug for Estrous Synchrony
| FACTREL Injection | GONAbreed Injectable Solution | |
|---|---|---|
| Manufacturer | Zoetis Inc. | Parnell Technologies Pty Ltd |
| Active Ingredient | Gonadorelin hydrochloride | Gonadorelin acetate |
| For Estrous Synchrony, Use With: | LUTALYSE (dinoprost tromethamine) | Cloprostenol sodium |
Other than the two combinations listed in the table above, it is illegal to use GnRH products in combination with another drug for estrous synchrony.
By prescribing FDA-approved FACTREL, you’re choosing one of the only two marketed GnRH products shown to be safe and effective for use in combination with another drug for synchronizing estrous cycles in lactating dairy cows. Used together in a breeding program, FACTREL and LUTALYSE synchronize estrous cycles to allow fixed-time artificial insemination in lactating dairy cows.
FDA’s Center for Veterinary Medicine (CVM) is committed to promoting and protecting animal health by ensuring safe and effective drugs are available for animals. For more information, please contact the CVM Communications Staff at 240-276-9300 or AskCVM@fda.hhs.gov.
Sincerely,
Daniel G. McChesney, Ph.D.
Director, Office of Surveillance and Compliance
Center for Veterinary Medicine