Dear Veterinarian:
In April 2023, the U.S. Food and Drug Administration approved Bimasone (flumethasone injectable solution) for use in horses, dogs, and cats for the various rheumatic, allergic, dermatologic, and other disease states which are known to be responsive to the anti-inflammatory corticoids. The product is now being marketed.
Drug Information
Bimasone is the first generic flumethasone product to receive FDA approval. Bimasone is a corticosteroid drug. It contains the same active ingredient (flumethasone) in the same concentration and dosage form as the approved brand name (reference-listed) drug product, Flucort Solution. Flucort Solution was first approved for use in horses, dogs, and cats on October 21, 1965, and is no longer marketed.
In horses, Bimasone is approved for intravenous, intramuscular, or intra-articular injection and is indicated for musculoskeletal conditions due to inflammation, where permanent structural changes do not exist, such as bursitis, carpitis, osselets, and myositis. It is also indicated for use in allergic states such as hives, urticaria, and insect bites.
FDA-approved drugs have been demonstrated to be safe and effective for their intended use and are required to comply with Current Good Manufacturing Practice (CGMP) that assures the drugs’ identity, strength, quality, including potency and sterility, and purity. When flumethasone is indicated for use in an equine, canine, or feline patient, the FDA strongly encourages veterinarians to use the FDA-approved Bimasone. As with all approved animal drugs, the FDA will monitor and evaluate submitted adverse event reports for Bimasone, which would include monitoring for potential human safety risks associated with administration of the drug.
Benefits of FDA Approval
The FDA wants to remind you of the benefits of FDA approval. Animal drugs, including generics, are rigorously evaluated by the FDA before approving them. As part of the generic approval process, the drug company must prove to the FDA that:
- There are data to support that the drug is bioequivalent to the FDA-approved name brand (reference-listed) drug, Flucort Solution. This means that the drug is expected to act the same way in the animal and, therefore, it is presumed safe and effective for a specific use in the intended species;
- The manufacturing process is adequate to preserve the drug’s identity, strength, quality, and purity; and
- The drug’s labeling is truthful and not misleading.
The 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;
- The manufacturing process to ensure that the identity, strength, quality, and purity of the drug are maintained;
- The drug’s labeling to make sure the information remains truthful and not misleading; and
- The company’s marketing communications related to the drug to make sure the information is truthful and not misleading.
Safety and Effectiveness of Bimasone Compared to Compounded Forms of Injectable Flumethasone
Animal drugs compounded from bulk drug substances are not FDA-approved drugs (pioneer or generic). The agency is aware that flumethasone formulations compounded from bulk drug substances may be available through some compounding pharmacies. Unlike FDA-approved Bimasone, compounded and other unapproved formulations of flumethasone have not been evaluated by the FDA for safety or effectiveness and may vary in quality, potency, and bioavailability. It is particularly important for injectable medications, such as flumethasone, to be sterile.
In contrast to FDA-approved Bimasone, the absorption and bioavailability of compounded formulations of injectable flumethasone are unknown and may be inadequate or variable. Further, while there are many post-approval requirements for sponsors of FDA-approved animal drugs, including the mandatory reporting of adverse drug experience reports, there are no such mandatory reporting requirements for compounded drugs. The FDA encourages veterinarians and animal owners to report adverse drug experiences and product defects associated with animal drugs, regardless of whether they are FDA-approved, and animal devices. More information about how to report information about animal drugs and devices can be found at our website: www.fda.gov/reportanimalae.
Sincerely,
FDA’s Center for Veterinary Medicine
Related Reading
- A Systematic Approach to Managing the Pruritic Horse
- Flumetasone’s Effects on Inflammation in Horses
- Causes of Immune-Mediated Myopathies in Horses
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