FDA approves first generic florfenicol–flunixin injectable (nixiFLOR) for bovine respiratory disease

The U.S. Food and Drug Administration has approved nixiFLOR(florfenicol and flunixin meglumine) injectable solution for treatment of bovine respiratory disease (BRD) and control of BRD-associated pyrexia in beef and non-lactating dairy cattle. The agency designated nixiFLOR as the first FDA-approved generic equivalent of the branded combination product Resflor GOLD (Merck).1

nixiFLOR combines florfenicol, a broad-spectrum antibiotic active against common BRD pathogens, with flunixin meglumine, a nonsteroidal anti-inflammatory used to reduce fever and inflammation. The FDA determined the product is bioequivalent to the reference listed drug and that tissue residues from labeled use do not pose a public-health concern when the label is followed.1

The approved label specifies a single subcutaneous injection in the neck at a dose providing 40 mg florfenicol/kg and 2.2 mg flunixin/kg (equivalent to 6 mL per 100 lb). The label also limits injection volume to no more than 10 mL per site and establishes a 38-day withdrawal interval for animals entering the food supply. nixiFLOR will be available byveterinaryprescription only, reflecting the need for professional diagnosis and oversight in BRD cases.1-2

Resflor GOLD (Merck)—the originator product for which nixiFLOR is an approved generic equivalent—is indicated for BRD associated with key bacterial pathogens including Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, and Mycoplasma bovis; the new generic carries the same labeled indications. Clinicians should note that the NSAID component may transiently reduce fever and clinical signs. Treated cattle should be re-evaluated per label instructions and antimicrobial stewardship principles should guide product selection and use.2

Practitioners incorporating nixiFLOR into BRD protocols should review the full FDA FOI summary and the product label for dosing, injection-site limits, withdrawal times, and monitoring recommendations.3

References

1. US Food and Drug Administration, Center for Veterinary Medicine. FDA approves first generic florfenicol and flunixin meglumine injection for bovine respiratory disease and associated pyrexia in beef and non-lactating dairy cattle.FDA website. Published January 22, 2026. Accessed January 23, 2026. https://www.fda.gov/animal-veterinary/cvm-updates/fda-approves-first-generic-florfenicol-and-flunixin-meglumine-injection-bovine-respiratory-disease.
2. RESFLOR GOLD prescribing information. DailyMed. Accessed January 23, 2026. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e622cfd8-2749-4a6f-b347-988806432c88.
3. Parnell Technologies Pty. Ltd.; U.S. FDA Freedom of Information (FOI) Summary. FREEDOM OF INFORMATION SUMMARY: nixiFLOR (florfenicol and flunixin meglumine) injectable solution; ANADA 200-828. FOI summary. Published January 9, 2026. Accessed January 23, 2026. https://animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadFoi/17926