DOXYLAMINE WARNING LABELS TO BE DISCUSSED BY OTC DRUGS ADVISORY COMMITTEE

DOXYLAMINE WARNING LABELS TO BE DISCUSSED BY OTC DRUGS ADVISORY COMMITTEE on the first day of the panel's June 28-29 meeting, FDA announced in a May 17 Federal Register notice. The committee will discuss labeling for OTC drug products containing doxylamine succinate "to alert consumers that studies have shown an increase in the development of tumors in laboratory animals administered this ingredient," FDA stated. FDA put off a decision on whether doxylamine should remain a monograph ingredient when it published the antihistamine final monograph in December. The agency placed doxylamine in Category I (safe and effective) in the antihistamine tentative final monograph, published in January 1985. However, an April 1991 rodent study conducted by the National Center for Toxicological Research indicated that the ingredient is an animal carcinogen. In June 1991, the issue was brought before FDA's Pulmonary-Allergy Drugs Advisory Committee, which recommended that doxylamine remain available over-the-counter but that there be some warning to consumers that the animal tumorigenicity data exist. Shortly after the June 1991 meeting, FDA suggested a warning for doxylamine-containing OTCs modeled on the warning statement for saccharin: "WARNING: Use of this product may be hazardous to your health. This product contains doxylamine succinate which has been determined to produce tumors in laboratory animals." The agency invited comments on the warning, but never issued a Federal Register notice proposing an official cautionary statement. FDA noted that it will consider the OTC advisory committee's recommendations on doxylamine use as an antihistamine when making a final decision, which will be published in the Federal Register "at a later date." Recommendations made by the advisory group also will apply to doxylamine used in "OTC nighttime sleep-aid products marketed under approved applications," the notice states. In a May 7 letter informing the Nonprescription Drug Manufacturers Association of the June 28 meeting topic, FDA stressed that the advisory committee "will discuss labeling only and not . . . the laboratory animal data." The agency emphasized to NDMA that "it is important that you and your members be prepared to discuss labeling options" at the June 28 session. In September 1991, NDMA made comments to FDA regarding a labeling warning on the rodent tumorigenicity warnings for doxylamine-containing OTC drug products. Doxylamine is contained in several OTC products including Procter & Gamble's NyQuil and Pfizer's Unisom. Also on June 28, the OTC advisory committee will have an "informational briefing on the regulation of advertising of OTC drug products by the Federal Trade Commission," FDA reported in the notice. The briefing is intended to "inform the committee how OTC drug products are regulated," FDA explained, "and is not directly related to any issues currently under consideration by the committee or the agency." On the second day of the advisory committee meeting, the group will discuss the relationship between alcohol and acetaminophen- induced liver toxicity ("The Tan Sheet" May 17, p. 1). Data on the topic that were submitted since the November 1988 OTC internal analgesic, antipyretic and antirheumatic drug products tentative final monograph will be considered to determine "whether the totality of the information warrants label revisions concerning the use of OTC dosages of acetaminophen with alcohol," according to the notice. In the 1988 TFM, FDA evaluated data on the "role of microsomal enzyme inducers, including alcohol, in acetaminophen-induced liver damage," the notice points out. Whitehall and McNeil also have made submissions to FDA on the issue. Whitehall, for example, proposed label warnings for acetaminophen-containing OTC products concerning alcohol and made comments on changing the maximum daily dose of acetaminophen for alcohol abusers. In a May 11 letter, Whitehall also suggested to FDA that "because of the widespread availability of both acetaminophen and alcohol, virtually all [study] authors recommend that both the physician and consumer be adequately warned of the potential alcohol-acetaminophen reaction." The firm included with its letter additional references from the medical literature on acetaminophen-alcohol and clarifications of its previous submissions to the agency. The June 28-29 meeting will begin at 8 a.m. on both days in conference rooms D & E of FDA's Parklawn Building, 5600 Fishers Lane, Rockville, Md. Preceding the June 28-29 session will be a June 1-2 joint meeting of the OTC Drugs Advisory Committee and the Arthritis Drugs Advisory Committee to discuss Syntex' NDA (20-204) for an Rx-to-OTC switch of Naprosyn (naproxen) ("The Tan Sheet" May 3, In Brief). The two committees also will address guidelines for juvenile rheumatoid arthritis. The meeting begins at 8:30 a.m. in conference rooms D & E of the Parklawn Building on June 1; proceedings on June 2 are closed to the public.