Animal & Veterinary

PRASCEND (pergolide mesylate) Tablets - Pharmacy Professionals

April 20, 2012

Dear Pharmacy Professional:

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 FDA approval 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.
Disease InformationEquine Cushing’s Disease is caused by the dysfunction of the pars intermedia, the intermediate lobe of the pituitary gland. The pituitary gland is not properly inhibited by dopamine. This loss of inhibition results in the overproduction of hormones, including ACTH and MSH. These hormones, in turn, cause overproduction of glucocorticoids by the adrenal glands.

The disease is also called hyperadrenocorticism. It is most often seen in older horses that have decreased levels of dopamine.

Clinical Signs:

  • Shaggy hair coat (hirsutism)
  • Excessive sweating
  • Increased appetite, drinking, and urination
  • Lethargy and poor performance
  • Potbellied appearance
  • Muscle loss
  • Abnormal fat distribution
  • Chronic or relapsing laminitis (inflammation of the feet)

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.

Please be aware that pergolide products should not be imported from other countries for use in animals. Also, 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 be asked to compound pergolide formulations for specific patients that need strengths or dosage forms not offered by PRASCEND. In these limited cases, pergolide can be legally compounded if:

  • It is done by or on the order of a licensed veterinarian within the practice of veterinary medicine; and
  • You use 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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