Keeping Drug Residues out of Milk: A Lesson in Industry Education
Young, Frank E., FDA Consumer
A Lesson in Industry Education Keeping Drug Residues Out of Milk
Last year I discussed in this column FDA's role as an educator, helping to solve public health problems by providing information and guidance to consumers, health professionals, and FDA-regulated industry. This role is especially important when a problem is due to the way a health product-a drug or medical device, for example-is used, and not to a flaw in the product itself. Education often proves more effective in solving such problems than does regulatory or legal action.
I'm pleased to be able to cite a recent success story in which FDA played a vital educational role. The story begins in March of last year, when FDA conducted a survey of milk from stores in 10 major cities across the country. Laboratory analysis found small residues of the veterinary antimicrobial sulfamethazine in 36 of 49 samples tested.
These findings were particularly disturbing for a number of reasons. First, it is illegal to use sulfamethazine in milk-producing cows. So, even though 25 of the 36 positive samples were below 5 parts per billion (ppb)--amounts so small that the reliability of the results couldn't be guaranteed--the fact that any residues were showing up in milk was a sign of trouble.
Second, some people are allergic to sulfa drugs, including sulfamethazine (although the levels found in the March survey were probably too low to cause a reaction).
Third, the safety of sulfamethazine for use in any food-producing animal had recently been called into question by a study just completed at FDA's National Center for Toxicological Research. The study found that sulfamethazine--used legally since the 1950s to treat respiratory and other diseases and promote faster weight gain in hogs, cattle, and other animals--produced cancerous tumors in mice and rats. The findings raised the question of whether the drug might cause cancer in humans as well. (That study is currently under review; if its findings are supported, FDA may need to modify or ban the use of sulfa drugs in food-producing animals.) It was particularly distressing that residues of the drug were turning up in such a basic food as milk--consumed by almost all our children and most adults every day.
Based on the results of its survey, and on similar reports of sulfa residues in milk published in scientific and dairy industry journals, FDA considered its options. The problem was not use of an illegal drug but illegal use of a legal drug--in other words, a user problem. The solution, FDA believed, could best be found through educating dairy farmers and veterinarians. And that could best be done with the help of other organizations in both government and industry.
So, in early April FDA met with representatives of dairy trade associations, the American Veterinary Medical Association, and the National Conference on Interstate Milk Shipments (NCIMS), which represents the milk inspection agencies in all 50 state. …