The US Food and Drug Administration review of the safety and effectiveness of nonstandardized allergen extracts

Abstract

Nonstandardized allergen extracts have been used for a century. Until 1972, these products were regulated by the National Institutes of Health, and products were not required to have an individualized showing of effectiveness. Jurisdiction was then transferred to the US Food and Drug Administration (FDA), which established external review panels to make recommendations regarding safety and effectiveness. Two external panels deliberated, the first from 1974-1979 and the second from 1982-1983. We sought to review external panels' recommendations and assess the safety and effectiveness of nonstandardized allergen extracts, FDA-reviewed available literature, and databases since 1972. Currently licensed nonstandardized allergen extracts were reviewed according to extract type. Available data were collected from medical and nonscientific search engines. Nomenclature was ascertained by consulting www.itis.gov or www.atcc.org. The FDA's Adverse Event Reporting System was probed for events associated with extract use. Provisional threshold levels of safety and effectiveness were established, and extracts were sorted according to whether they met the thresholds. In the Adverse Event Reporting System, there were 178 adverse event reports, including 13 deaths, associated with allergen extract use over 23 years. No single group of extracts predominated. Among 1269 allergen extracts reviewed, there were 480 for which use in the diagnosis and treatment of allergic disease were addressed in the literature, 207 for which only diagnostic use was addressed, 565 for which minimal or no supportive literature was identified, and 17 for which potential safety concerns were found. When used according to professional guidelines, almost all nonstandardized allergen extracts for diagnosis and therapy appear to be safe. Provisional thresholds of effectiveness were met by 54% of extracts reviewed.