ATTAPULGITE, POLYCARBOPHIL AND CALCIUM POLYCARBOPHIL ARE CATEGORY I INGREDIENTS UNDER FDA's OTC ANTIDIARRHEAL DRUG PRODUCTS TENTATIVE FINAL MONOGRAPH

Attapulgite, polycarbophil and calcium polycarbophil are Category I OTC antidiarrheals under FDA's OTC Antidiarrheal Drug Products Tentative Final Monograph (TFM) published in the April 30 Federal Register. The three are the only ingredients proposed by FDA in the TFM to be "generally recognized as safe and effective." Polycarbophil was recommended by the Advisory Review Panel on OTC Laxative, Antidiarrheal, Emetic and Anti-emetic Drug Products for a Category I classification in treating diarrhea. However, the panel made no recommendations regarding calcium carbophil. Explaining its reasons for listing calcium polycarbophil Category I in the TFMs, FDA said that the ingredient "can be considered to be therapeutically identical to polycarbophil [because] the calcium ion does not alter either the chemical or pharmacological effect of polycarbophil." FDA noted in the TFM that comments to the agency on the panel's report, which was published in the March 21, 1975 Federal Register, had "explained that inclusion of calcium polycarbophil in the monograph would permit the formulation of polycarbophil in liquid as well as solid dosage forms, because calcium polycarbophil is not hydrosorptive and can be used in a liquid medium." Attapulgite was reclassified from Category III to Category I based on a clinical study submitted by Pfizer comparing the efficacy of two 600 mg attapulgite tablets versus placebo in 50 patients. Results of the double-blind, randomized trial "indicated that the subjects of the active group had significantly fewer bowel movements, better stool consistency, and fewer cramps than the subjects of the placebo group (p<.0001)," the TFM states. FDA said that based on the results of the study, it is proposing that attapulgite be indicated for: (1) "[Reducing] the number of bowel movements in diarrhea," and (2) "[Improving] consistency of loose, watery bowel movements in diarrhea." FDA is proposing in the TFM that diarrhea products be labeled for up to three claims -- reducing the number and improving the consistency of bowel movements as well as: "'For the treatment of diarrhea' or 'Controls (stops) diarrhea.'" The TFM explains, "One or more of these indications may be included in the labeling of OTC antidiarrheal drug products, depending on the results of studies conducted on the ingredient contained in the product." FDA noted that claims would also be allowed for relief of symptoms that are secondary to diarrhea, "such as abdominal pain or cramps." The TFM explains, however, that such claims can not be "considered as primary indications for use of an OTC antidiarrheal drug product. Therefore, indications for relief of symptoms secondary to diarrhea will be allowed in the labeling of an OTC antidiarrheal drug product only when the product meets the criteria of one or more" of the three allowed primary indications. With the exception of opiate ingredients, the TFM Category II and III classifications followed the panel report's recommendations. The panel had recommended opiate ingredients (opium powder, tincture of opium, and paregoric) as Category I antidiarrheals. FDA said that opiate ingredients were switched because they may be "marketed for OTC use in combination only [and] no data have been submitted to support combinations of opiates and other active ingredients." An additional change made to the panel report in the TFM is that the agency is proposing to allow combination products containing "two or more safe and effective active ingredients." The 1975 proposal recommended "that Category I antidiarrheal combination drug products be limited to two Category I active ingredients," FDA noted. The agency is accepting written comments on the TFM until June 30, 1986, and new data demonstrating safety and efficacy of ingredients not in Category I until June 30, 1987.