The US Food and Drug Administration published a proposed final rule to prohibit the extra-label use in poultry of two classes of approved human antiviral drugs in treating influenza. FDA is taking this measure to help preserve the effectiveness of these drugs for treating or preventing influenza infections in humans.

Specifically, the order prohibits the extra-label use by veterinarians of anti-influenza adamantane (amantadine and rimantadine) and neuraminidase inhibitor (oseltamivir and zanamivir) drugs in chickens, turkeys, and ducks. Extra-label use is the actual use or intended use of a drug in an animal in a manner that is not in accordance with the approved labelling.

"The action is a preventive measure designed to protect the public health and illustrates FDA's high level of commitment and key role in preparing for a possible influenza pandemic, which is a top priority for our nation," said Acting FDA Commissioner Dr. Andrew von Eschenbach.

Currently, no drugs are approved for the treatment or prevention of influenza A in animals. However, two classes of antiviral drugs are approved in the United States for the treatment or prevention of influenza A in humans. Under the Animal Medicinal Drug Use Clarification Act of 1994 (AMDUCA) veterinarians can legally prescribe these human antiviral drugs to protect animals from influenza.

Under AMDUCA and its implementing regulations, FDA can issue an order prohibiting certain extra-label uses in animals if such extra-label use presents a risk to the public health. FDA has considered all available information and has concluded that the extra-label use of anti-influenza adamantane and neuraminidase inhibitor drugs in chickens, turkeys, and ducks presents a risk to public health. FDA may add other animal species to the prohibited list as new data becomes available, said the FDA release.