ANTIHISTAMINE WARNING STATEMENT ON USE IN ASTHMA PATIENTS SHOULD BE DELETED "AS SOON AS POSSIBLE," FDA’s PULMONARY-ALLERGY COMMITTEE CONCLUDES

The warning statement in both OTC and Rx antihistamine labeling that contraindicates use in asthma patients should be removed, FDA's Pulmonary-Allergy Drugs Advisory Committee recommended at its June 12 meeting. Committee Chairman Leonard Bernstein, MD, University of Cincinnati Medical Center, asked the group: "Do we as a committee now wish to recommend that the statement about possible adverse effects of antihistamines in the treatment of asthma be rescinded as soon as possible?" All of the members, with one abstention, voted affirmatively in response to the question. There were no "opposing" votes. In a presentation on the use of antihistamines in asthma patients, FDA consultant William Pierson, MD, University of Washington, asked the committee to consider recommending that the label warning be removed. The contraindication poses a medical dilemma for physicians, Pierson pointed out. "I think that upper respiratory tract disorders, especially allergic rhinitis, pollinosis, [and] hay fever, are clear indications for the use of antihistamines," he said. "The problem is, especially if you take care of children and adolescents, many of our patients with asthma are also afflicted with these upper airway disorders. So we are on the immediate horns of a dilemma of when there is a noted contraindication or warning about the use of antihistamines in lower respiratory tract diseases, specifically asthma." At a May 15 conference sponsored by "F-D-C Reports," Pierson called the fact that antihistamines are contraindicated for asthmatics "a scientific myth that has astounded us in its survivability with no data." He noted that the contraindication was based on a belief during the early development of antihistamines that they had anticholinergic or atropine-like activity ("The Pink Sheet" May 21, T&G-5). During the panel meeting, Pierson observed that he made a similar presentation on the labeling issue to the committee in 1982. Two years ago, Pierson said, a committee of the American Academy of Allergy and Immunology issued a position statement that said "revised labeling was clearly needed." Pierson referred to a study in which the antihistamine chlorpheniramine was expected to worsen airway function -- when in fact patients' lung function improved. He also noted that the antihistamine terfenadine (Marion Merrell Dow's Seldane) has been shown to block both early- and late-phase asthmatic responses to allergen challenge and block exercise-induced asthma. Labeling for Seldane contains the statement: "Consideration should be given to potential anticholinergic (drying) effects in patients with lower airway disease, including asthma." The labeling for Janssen's Hismanal (astemizole) contains a very similar statement. OTC antihistamines also contain label warnings against taking the products if a person has asthma. For example, labeling for Parke-Davis' OTC antihistamine Benadryl products have the warning: "Do not take this product if you have asthma, glaucoma, emphysema, chronic pulmonary disease...unless directed by a physician."