COMMON COLD INDICATION FOR OTC ANTIHISTAMINES GETTING SECOND LOOK FROM FDA AS AGENCY WORKS ON FINAL MONOGRAPH; PHENYLPROP STILL UNDER DISCUSSION

The Category I status for antihistamines for relief of cold symptoms is getting further consideration by FDA as the agency works on the final antihistamine monograph. FDA Pulmonary Drugs Group Leader Eileen Leonard, MD, disclosed the agency's renewed interest in the OTC status of antihistamines for cold symptoms during a presentation to the March 23 meeting of the agency's Pulmonary-Allergy Drugs Advisory Committee. She observed that FDA is giving "some additional thought and review time" to antihistamine indications for the common cold. The agency's interest in the antihistamine indication apparently stems from a previous decision to let data on one ingredient (chlorpheniramine) support claims for a wide variety of antihistamines. Under the Tentative Final Monograph for OTC antihistamines, published on Jan. 15, 1985, all Category I antihistamines may carry an indication "for temporary relief of runny nose and sneezing associated with the common cold." FDA based that decision on studies providing "evidence that chlorpheniramine is significantly more effective than a placebo in alleviating the symptoms...associated with the common cold." The TFM states that because the various Category I antihistamines exhibit similar "pharmacologic actions," the agency believed that chlorpheniramine was representative of all OTC antihistamines. Therefore, FDA concluded in the TFM that the data supporting Category I status for common cold claims could be extended to support common cold claims for all Category I antihistamine active ingredients. Leonard explained to the advisory committee that the agency is now undertaking a review of the data and will decide if a "reconsideration" is warranted. The antihistamine monograph has not been one of the near-term completion projects mentioned by the agency in its most recent predictions on upcoming publications. FDA is planning an in-house session in April to discuss various issues connected with antihistamines. The agency's desire to revisit the antihistamine monograph may be colored by congressional interest in the subject. Rep. Weiss (D-N.Y.) has expressed interest recently in the OTC status of antihistamines, and his staff is believed to be doing some spadework for a possible hearing. FDA also continues to look "at the issue of PPA [phenylpropanolamine]," Leonard told the advisory committee. The agency is attempting to determine whether the use of the ingredient "may be associated with adverse reactions such as hypertension." FDA's "final determination" will be included in the Final Monograph, Leonard added, "and whatever action is taken will apply to all products in this drug class." Phenylpropanolamine, both as a diet aid and as a nasal decongestant, has been under scrutiny for several years. During the Nov. 15, 1990 Nonprescription Drug Manufacturers Association's Research & Scientific Development Conference, FDA OTC Drug Evaluation Director William Gilbertson announced FDA's intention to ask manufacturers to reduce the nasal decongestant dose from 37.5 mg to 25 mg. Rep. Wyden (D-Ore.) has maintained an interest in the safety profile of phenylpropanolamine. Wyden mentioned the agency's continuing review of the ingredient in comments on a study of OTC regulation conducted by the General Accounting Office at his request ("The Pink Sheet" March 2, T&G-11). Wyden has pushed in the past for a third drug class (restricted-access OTCs), but even his staff has begun to cool on the project, acknowledging publicly that the concept does not have much legislative appeal ("The Pink Sheet" Sept. 9, 1991, T&G-10). Rep. Dingell (D-Mich.) asked the Office of Technology Assessment to conduct a further study on the feasibility and advisability of a third class of drugs earlier this year ("The Pink Sheet" Feb. 10, T&G-5).