Phenylbutazone in Horses - Pharmacy Professionals

October 16, 2009

Dear Pharmacy Professional:

Phenylbutazone is a non-steroidal anti-inflammatory drug commonly prescribed by veterinarians for the relief of inflammatory conditions associated with the musculoskeletal system in horses.  There are 48 actively-marketed phenylbutazone products that are approved by the U.S. Food and Drug Administration (FDA) for use in horses (please refer to the complete product list below).  These products are available in multiple dosage forms, including oral tablets, boluses, pastes, and powders; and solutions for intravenous injection.  Two of the approved powders are flavored for use in feed.      

Each FDA-approved animal drug goes through a rigorous evaluation process, and prior to approval, is clinically tested for safety and effectiveness in the target animal species.  In addition, the FDA thoroughly inspects and evaluates the adequacy of the manufacturing process to ensure that the drug’s identity, strength, quality, and purity are preserved.  The FDA continues to monitor the drug’s quality and safety after it is approved. 

The numerous FDA-approved phenylbutazone products for horses, available in multiple dosage forms and two flavors, greatly reduce the need for compounding.  In very limited cases, you may be asked to compound phenylbutazone for specific patients that require phenylbutazone in a strength or dosage form that is not available among the approved products.  In these instances, phenylbutazone can only be legally compounded if it is done by or on the order of a licensed veterinarian within the practice of veterinary medicine, and if an FDA-approved phenylbutazone product is used as the starting material.  Phenylbutazone should not be compounded from bulk.  An animal drug that is compounded from bulk drug ingredients is not FDA-approved, and therefore, the safety and effectiveness of the compounded drug, as well as the adequacy of the manufacturing process, have not been evaluated. 

The requirements for legal animal drug compounding can be found in Title 21, Code of Federal Regulations, Section 530.13.

At the FDA’s Center for Veterinary Medicine (CVM), we are committed to promoting and protecting animal health by ensuring that safe and effective drugs are available for veterinary use. 

For more information, please contact the Communications Staff at CVM at 240-276-9300 or AskCVM@fda.hhs.gov.

Sincerely,

The FDA’s Center for Veterinary Medicine

FDA-Approved Phenylbutazone Products for Horses

The following is a complete list of the actively-marketed FDA-approved phenylbutazone products for horses as of September 16, 2009.  All FDA-approved products have a New Animal Drug Application (NADA) number, or for generic products, an Abbreviated New Animal Drug Application (ANADA) number.  The six-digit (A)NADA number and the statement “Approved by FDA” can usually be found on the product label.  The same product may be distributed by more than one company under different trade names.  Several products may be marketed under one (A)NADA number.  

NADA number:  044-756
Sponsor:  Cross Vetpharm Group Ltd

NADA number:  048-647
Sponsor:  First Priority Inc

NADA Number:  091-818
Sponsor:  Teva Animal Health

NADA number:  094-170
Sponsor:  Teva Animal Health

NADA number:  113-510
Sponsor:  Vetoquinol N A Inc

NADA number:  116-087
Sponsor:  Intervet Inc

NADA number:  140-958
Sponsor:  Luitpold Pharmaceuticals, Inc

ANADA number:  200-126
Sponsor:  Teva Animal Health

ANADA number:  200-323
Sponsor:  West-Ward Pharmaceutical Corporation

ANADA number:  200-333
Sponsor:  Superior Equine Pharmaceuticals, Inc

ANADA number:  200-334
Sponsor:  A & G Pharmaceuticals Inc

*Citrus-flavored

ANADA number:  200-371
Sponsor:  Sparhawk Laboratories Inc