On February 28, 2003, FDA issued an order prohibiting the
extralabel use of
Phenylbutazone in female dairy cattle 20 months of age and
older. The
following is from FDA's official announcement:
The Food and Drug Administration (FDA) is issuing an order
prohibiting the
extralabel use of phenylbutazone animal and human drugs in
female dairy
cattle 20 months of age or older. FDA is issuing this order
based on
evidence that extralabel use of phenylbutazone in these
dairy cattle will
likely cause an adverse event in humans. The Agency finds
that such
extralabel use presents a risk to the public health for the
purposes of the
Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA).
AMDUCA amended the Federal Food, Drug, and Cosmetic Act to
allow licensed
veterinarians to prescribe extralabel uses of approved
animal drugs and
human drugs in animals. Section 2(a)(4)(D) of the AMDUCA
provides that the
Agency may prohibit an extralabel drug use in animals if,
after affording an
opportunity for public comment, the Agency finds that such
use presents a
risk to the public health.
Phenylbutazone became available for use in humans for the
treatment of
rheumatoid arthritis and gout in 1949. However, it is no
longer approved,
and thus not marketed, for any human use in the United
States. This is
because some patients treated with phenylbutazone have
experienced severe
toxic reactions, and other effective, less toxic drugs are
available to
treat the same conditions.
Phenylbutazone is known to induce blood dyscrasias,
including aplastic
anemia, leukopenia, agranulocytosis, thrombocytopenia and
deaths.
Hypersensitivity reactions of the serum-sickness type have
also been
reported. In addition, phenylbutazone is a carcinogen, as
determined by the
National Toxicology Program.
For animals, phenylbutazone is currently approved only for
oral and
injectable use in dogs and horses. Use in horses is limited
to use in horses
not intended for food. There are currently no approved uses
of
phenylbutazone in food-producing animals.
Investigation by FDA and State regulatory counterparts has
found
phenylbutazone on farms and identified tissue residues in
culled dairy
cattle. In addition, USDA's Food Safety Inspection Service
has reported
phenylbutazone residues in culled dairy cattle presented for
slaughter for
human food throughout the U.S. in the past two calendar
years. This evidence
indicates that the extralabel use of phenylbutazone in
female dairy cattle
20 months of age or older will likely result in the
presence, at slaughter,
of residues that are toxic to humans, including being
carcinogenic, at
levels that have not been shown to be safe.
FDA will consider all comments on this order that the Agency
receives by
April 29, 2003. Written comments should be submitted to the
Dockets.Management Branch (HFA-305), Food and Drug Administration, 5630 Fishers
Lane, Room 1061, Rockville, MD 20852. Submit electronic
comments to
http://www.fda.gov/dockets/ecomments.
All comments should include Docket
number 03N-0024. The order will become effective May 29,
2003, unless FDA
revokes or modifies the order or extends the comment period.
Additional information on this prohibition is contained in
the February 28,
2003, Federal Register (http://www.fda.gov/OHRMS/DOCKETS/98fr/03-4741.htm
).
Questions about this prohibition may be directed to: Gloria
J. Dunnavan,
Center for Veterinary Medicine (HFV-230), Food and Drug
Administration, 7500
Standish Place, Rockville, MD 20855, 301-827-1168, e-mail:
gdunnava@cvm.fda.gov.
Lewis R Jones, Chief
Ohio Department of Agriculture
Dairy Division
jones@odant.agri.state.oh.us
Phone: (614) 644-8621
Fax: (614) 728-2652