U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
FDA Prime Connection

CVM Announces Opinion on Dipyrone Products
 
 
     CVM ANNOUNCES OPINION ON DIPYRONE PRODUCTS
 
 
CVM is announcing that all dipyrone products must have an approved new
animal drug application (NADA) to remain on the market.  The Center is
taking this position because a survey found evidence of extra-label use in
food-producing animals.  The scientific literature lacks adequate data to
show that dipyrone is safe and effective.  There is no information on
pharmacokinetics, and no regulatory method exists for assay of dipyrone
or its metabolites in milk or meat.
 
The use of dipyrone has been associated with bone-marrow toxicity,
severe agranulocytic anemia, dose independent teratogenicity, induction of
the microsomal enzyme system, and a tendency to increase bleeding times
by suppressing the formation of prothrombin.  Toxicity concerns led FDA
to withdraw approval of all dipyrone-containing products for use in
humans in 1977.
 
In addition, CVM is concerned that these unapproved dipyrone products
unfairly compete with other drugs which have been approved.  Dipyrone
injectables have been sold as prescription products for use in certain
non-food animals.  While these dipyrone animal products have never been
the subject of approved NADAs, FDA has permitted their sale under
regulatory discretion.  The labeled use of dipyrone has been as an
injectable analgesic/antipyretic for horses, dogs, and cats.  The label of
these marketed products specifically prohibits use in food animals.
 
Dipyrone products are in violation of the Federal Food, Drug, and
Cosmetic Act.  In letters to all known manufacturers and distributors of
dipyrone, CVM has advised that these products now must be approved.
Regulatory discretion for marketing these products will no longer be
granted because of concerns about safety, effectiveness, and fairness to
other approved drug products.
 
Additional information on this subject is available from FDA, Center for
Veterinary Medicine, Office of Surveillance and Compliance, HFV-200,
7500 Standish Place, Rockville, MD 20855, (301) 594-1761.