FDA extends call for treatment limit ideas

Food and Drug Administration authorities have extended a call for ideas on how to limit durations of some approved antimicrobial treatments in livestock.

In another notice, agency officials also confirmed that the agency’s rules applied to medicated feed production would change to avoid loss of some antimicrobial treatments for use in sheep, goats, and other minor species as restrictions took effect on uses in major species.

Agency officials are accepting ideas through March 13 on how to establish appropriate and targeted durations of use for antimicrobials that are considered important for human medicine, according to a Nov. 29, 2016, Federal Register notice announcing the 90-day comment period that began Sept. 14 would be extended 90 days.

A notice published at the beginning of the comment period indicates the limits would apply to approved antimicrobial uses in agriculture that lack treatment durations on their labels or provide instructions such as “feed continuously.” The agency has identified such drugs intended for administration to cattle, swine, chickens, turkeys, sheep, and honeybees.

“Establishing defined durations of use for currently approved therapeutics will support FDA’s efforts to foster stewardship of medically important antimicrobial drugs in food-producing animals and help preserve the effectiveness of these antimicrobials in animal and human medicine,” September’s notice states. “Some examples of defined durations of use on the labeling of currently approved therapeutics are ‘Feed continuously for 5 days,’ ‘Feed continuously for 5 days as the sole ration,’ ‘Feed from weaning up to 120 pounds,’ and ‘Do not feed to chickens over 16 weeks (112 days) of age.’”

The deliberations on treatment duration limits follow agency actions that, at press time, were expected to prohibit agricultural production uses in feed or water of antimicrobials important for human medicine and require veterinarian oversight for remaining uses by Jan. 1. All affected pharmaceutical companies had agreed to implement those changes, according to FDA announcements.

In related news, agency officials published another Federal Register notice the same day confirming a rule that will ensure drugs administered in animal feed for therapeutic purposes would remain available for administration to food-producing minor species—such as sheep, goats, catfish, game birds, and honeybees—after production uses are removed.

An announcement accompanying the notice indicates removing availability of some antimicrobials for production uses in major species—such as pigs or chickens—could have made those drugs less accessible for therapeutic use in minor species because of drug category definitions.

Related JAVMA content:

Restrictions on medicated feeds coming to farms (Nov. 1, 2016)