Warning labels for drugs with sulfites.

More than 1,100 prescriptin drugs contains sulfites to limit oxygen-mediated changes that might affect potency. However, as many as 10 percent of the nation's asthmatics -- 1 million people -- may be sulfite-sensitive and suffer life-threatening allergic-type reactions upon exposure to these chemicals (SN: 8/17/85, p. 100). So the Food and Drug Administration (FDA) is proposing that these drugs be labeled with a warning of their potential for triggering severe reactions. Most of the drugs in question are administered intravenously.

Many drug manufacturers have already volunteered to label products that contain the antioxidant. The Washington, D.C.-based Pharmaceutical Manufacturers Association, for example, whose members make the majority of U.S. prescription drugs, told FDA that as of Dec. 1 its expected its members would be listing all inactive ingredients -- including sulfites -- in the official pakcage insert for oral drugs. Members of the Proprietary Association, also based in Washington, who manufacture between 90 and 95 percent of all over-the-counter drugs sold in the United States, announced a similar measure. While this is useful, FDA contends that simply listing the ingredients is not enough. In fact, the agency notes, the only prescription drug confirmed to have caused a sulfite-mediated allergic reaction listed the ingredient on its label -- a listing that was overlooked by the attending health-care provider.