Animal & Veterinary

PRASCEND (pergolide mesylate) Tablets - Veterinarians

April 20, 2012

Dear Equine Veterinarian:

The U.S. Food and Drug Administration (FDA) wants to tell you about the approval of PRASCEND (pergolide mesylate) Tablets to control the clinical signs associated with Equine Cushing’s Disease. FDA also wants to remind you of the benefits of using FDA-approved drugs for your patients and the legal requirements for compounding animal drugs.

Drug Information

ManufacturerBoehringer Ingelheim Vetmedica, Inc.
Application TypeNew Animal Drug Application (NADA)
Application Number141-331
IndicationFor the control of clinical signs associated with Pituitary Pars Intermedia Dysfunction (Equine Cushing’s Disease) in horses
Active IngredientPergolide mesylate
How Supplied1 mg tablets
Clinical PharmacologyPergolide mesylate is a synthetic ergot derivative and a potent dopamine receptor agonist. As with other dopamine agonists, pergolide inhibits the release of prolactin which suggests that it may interfere with lactation. In horses with Pituitary Pars Intermedia Dysfunction (PPID), pergolide is believed to exert its therapeutic effect by stimulating dopamine receptors, and has been shown to decrease the plasma levels of adrenocorticotropic hormone (ACTH), melanocyte stimulating hormone (MSH), and other pro-opiomelanocortin peptides.

Please see the approval notice for PRASCEND in the Federal Register.

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 complete.

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 to determine if concerns arise that were not known at the time of approval;
  • Manufacturing process to ensure quality and consistency are maintained; and
  • Labeling to make sure the information remains truthful and complete.

By prescribing FDA-approved PRASCEND, you provide your clients and their horses with the only marketed pergolide product shown to be safe and effective for controlling the clinical signs associated with Equine Cushing’s Disease. PRASCEND is also the only marketed pergolide product that is manufactured to meet FDA’s strict standards for quality, purity, and potency.

Please be aware that pergolide products should not be imported from other countries for use in animals. In addition, bulk pergolide should not be used to compound animal drugs.

A compounded animal drug is not FDA-approved. This means FDA has not evaluated the safety and effectiveness of the compounded drug or the adequacy of the manufacturing process.

After human pergolide products were removed from the market in May 2007, FDA exercised enforcement discretion by allowing, in appropriate circumstances, the compounding of products from bulk pergolide for use in horses. With the approval of PRASCEND, the conditions under which the agency previously exercised enforcement discretion no longer exist. Please see FDA’s statement on the compounding of pergolide products for animal use.

You may have specific patients that need pergolide in strengths or dosage forms not offered by PRASCEND. In these limited cases, pergolide can be legally compounded by using FDA-approved PRASCEND as the source of the active pharmaceutical ingredient. Please find additional requirements for legal animal drug compounding at Title 21, Code of Federal Regulations, Section 530.13.

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 240-402-7002 or


FDA’s Center for Veterinary Medicine

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