FDA Approves Zimeta for Control of Fever in Horses

The U.S. Food and Drug Administration’s Center for Veterinary Medicine (FDA-CVM) announced November 26, 2019, that it has approved Zimeta (dipyrone injection) for the control of fever (known as pyrexia) in horses. Zimeta belongs to the pyrazolone class of non-steroidal anti-inflammatory (NSAID) drugs and is the first injectable dipyrone product to receive FDA approval for use in horses.

Zimeta is a prescription animal drug product containing 500 mg dipyrone/mL and is intended for intravenous injection once or twice daily (every 12 hours) for up to three days. As a class, NSAIDs may be associated with adverse effects on the gastrointestinal system, kidney, and liver, and decreased ability to form blood clots (coagulopathy). Zimeta has been shown to cause gastric ulcers, abnormal feces, and prolongation of coagulation parameters in horses. Horses on Zimeta should be monitored for signs of lack of appetite, diarrhea, or unexplained bleeding and caution should be used in horses at risk for hemorrhage.

Safe use of Zimeta in horses less than three years of age, horses used for breeding, or in pregnant or lactating mares has not been evaluated. Precautions should be employed by practitioners when handling and using loaded syringes to prevent contact with the skin and accidental self-injection, as studies have indicated that dipyrone can cause agranulocytosis in humans, a serious and potentially life-threating condition in which there is a white blood cell deficiency in a person’s blood that can increase one’s vulnerability to infection.

As with all approved animal drugs, the FDA will monitor and evaluate submitted adverse event reports for Zimeta, which would include monitoring for potential human safety risks associated with dipyrone and indications that the product is being used in an extra label manner in food-producing animals. Zimeta is manufactured by Kindred Biosciences, Inc., which is based in Burlingame, California.

Click here to read the full FDA announcement, including precautions for humans administering Zimeta and the history of dipyrone use in horses.