FDA adds oversight to over-the-counter antimicrobials

Food and Drug Administration regulators want veterinarian oversight for all antimicrobials shared between animal and human medicine.

Agency officials added such restrictions three years ago to drugs administered to livestock through feed or water, but some livestock-use injectable drugs and other antimicrobial products remain available to anyone. Draft guidance published in September describes a multiyear plan to change approvals for those remaining over-the-counter drugs.

To restrict drug use in livestock feed and water, FDA officials reached agreements with pharmaceutical companies to require veterinary feed directives when those drugs are administered in feed or prescriptions when they are added to water. Those agreements came under a threat of regulatory proceedings against any companies that refused, and none did.

This year's proposal calls again for cooperation by drug companies.

The guidance published in September is only a draft, subject to editing after the agency considers comments. It describes a two-year transition that would start once a final version is published.

When the FDA added oversight to the antimicrobials administered through livestock feed or water, agency officials published a draft document in April 2012 and the final document in December 2013. The latter document's publication started a three-year transition through December 2016.

FDA officials also announced plans to give researchers at Kansas State University $500,000 for two studies to help define how long some antimicrobials should be administered to cattle. Agency officials have a goal of setting use durations for drugs that were approved without them.

The studies involve use of tylosin phosphate to prevent liver abscesses in feedlots and chlortetracycline for treatment of bovine anaplasmosis.