SULFITE EVIDENCE OF CAUSAL LINK TO SERIOUS ADVERSE REACTIONS

SULFITE EVIDENCE OF CAUSAL LINK TO SERIOUS ADVERSE REACTIONS was cited by FDA in a proposed rule requiring a warning statement to be included in the professional labeling of all Rx products which use sulfites as a preservative. FDA said in the proposal, published in the Nov. 19 Federal Register, that: "Because there is evidence of a casual relationship between sulfites and serious reactions in certain susceptible persons . . . the agency concludes that individuals who wish to avoid sulfite-containing products should be provided with sufficient labeling information to do so." FDA is proposing that the professional labeling for all human Rx products containing sulfites include the warning statement: "Contains (insert the name of the sulfite, e.g., sodium metabisulfite), a sulfite that may cause serious allergic-type reactions (e.g., hives, itching, wheezing, anaphylaxis) in certain susceptible persons. Although the overall incidence of sulfite sensitivity in the general population is probably low, it is seen more frequently in asthmatics or in atopic nonasthmatic persons." The Center for Science in the Public Interest had petitioned FDA to ban the use of sulfites in asthmatic drug products and either ban the use of sulfites in all OTC and Rx products or require a warning label in products requiring sulfites in order to maintain drug stability and potency. FDA stated that it has "not found evidence in the available information on sulfites in human drugs that demonstrates a significant health hazard to the general population. Therefore, a complete prohibition against their use is not now justified." In addition, the agency said that because it "believes that sulfites serve a necessary public health function by maintaining the potency of certain medications, some of which may be life saving, prohibiting sulfite use in drug products could be justified only if acceptable alternatives were available." FDA said to its knowledge a general substitute has not yet been identified. "Moreover, with the exception of ascorbic acid, alternative antioxidants have not had wide exposure and could pose safety problems as severe or worse than with sulfites," FDA stated. With regard to OTC products, FDA noted that the voluntary actions by the OTC industry to list inactive ingredients on their products and the absence of any evidence of adverse reactions specifically related to OTC products containing sulfites, precludes regulatory action for OTC products at this time. FDA noted that its Drug Experience Div. received 14 reports of adverse reactions to sulfites, of which the only confirmed reaction involved an Rx product that listed sulfites on the label. FDA said the listing was overlooked by the attending health care professional and thus "a statement in the labeling is needed to help ensure that health care professionals are alerted to the problem." The agency also stated that the warning requirement should apply to all Rx products with sulfites regardless of the amount since FDA is "unaware of any evidence that establishes a level below which sulfites will not cause a reaction in sensitive individuals." FDA added that "although a dose-dependent response can be demonstrated in individual patients, establishment of a threshold level would not take into account highly sensitive asthmatics who might react to very small amounts."