The Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA) permits veterinarians to prescribe extra-label uses of certain approved new animal drugs and approved human drugs for animals under certain conditions. Extra-label use refers to the use of an approved drug in a manner that is not in accordance with the approved label directions. Under AMDUCA and its implementing regulations published at Title 21, Code of Federal Regulations, Part 530 (21 CFR 530), any extra-label use of an approved new animal or human drug must be by or on the lawful order of a veterinarian within the context of a veterinarian-client-patient relationship (VCPR). Extra-label use must also comply with other provisions of 21 CFR 530. A list of drugs specifically prohibited from extra-label use appears in 21 CFR 530.41.
"Extra-label use" is defined as:
"Actual use or intended use of a drug in an animal in a manner that is not in accordance with the approved labeling. This includes, but is not limited to, use in species not listed in the labeling, use for indications (disease and other conditions) not listed in the labeling, use at dosage levels, frequencies, or routes of administration other than those stated in the labeling, and deviation from labeled withdrawal time based on these different uses." (21 CFR 530.3(a))
Labeling of Drugs Prescribed for Extra-label Use
Any drug prescribed and dispensed for extra-label use by a veterinarian or dispensed by a pharmacist on the order of a veterinarian must bear or be accompanied by labeling information adequate to assure the safe and proper use of the drug. (21 CFR 530.12) At a minimum, such information shall include the following:
Prohibitions under AMDUCA
Under the AMDUCA provisions, FDA has the authority to prohibit extra-label uses of certain drugs in animals.
FDA may prohibit the extra-label use of an approved animal drug or approved human drug or class of drugs in food-producing animals if FDA determines that:
A prohibition may be a general ban on the extra-label use of the drug or class of drugs or may be limited to a specific species, indication, dosage form, route of administration, or combination of factors. 21 CFR 530.21
FDA may prohibit the extra-label use of an animal or human drug in nonfood-producing animals if FDA determines that such extra-label use presents a risk to the public health. 21 CFR 530.30
A list of drugs, families of drugs, and substances prohibited for extra-label use in animals appears in 21 CFR 530.41.