FDA's OTC ADVISORY COMMITTEE TO FOCUS ON ATTAPULGITE, KAOLIN

FDA's OTC ADVISORY COMMITTEE TO FOCUS ON ATTAPULGITE, KAOLIN as a single ingredient in OTC antidiarrheal products during the second day of the panel's April 8-9 meeting. FDA had originally planned to ask the advisory committee to evaluate the safety and efficacy of products containing both kaolin and pectin ("The Tan Sheet" March 8, p. 1). FDA told Public Citizen's Health Research Group in a March 17 letter that it is "asking that the committee only review kaolin alone as a single ingredient and attapulgite" in order for the agency to "complete the final monograph for OTC antidiarrheal drug products." HRG filed a citizen's petition in January seeking the market withdrawal of a number of OTC and prescription antidiarrheal products and an emphasis on oral rehydration solutions as first-step treatment for pediatric diarrhea. The HRG petition requests a ban of all OTC antidiarrheal products containing kaolin and pectin, activated charcoal and attapulgite. FDA explained that "activated charcoal and pectin are not included" in the committee's deliberations "because data are insufficient to support monograph status (generally recognized as safe and effective)." Kaolin and pectin were placed in Category III by FDA in an April 1986 tentative final monograph for OTC antidiarrheal products, while attapulgite was classified in Category I (safe and effective) in the TFM. The HRG petition also asked that pediatric formulations of loperamide and diphenoxylate hydrochloride with atropine sulfate be taken off the market. HRG's concerns about "both diphenoxylate hydrochloride, which is prescription only, and loperamide, which is not recommended for children under six years of age" will be addressed in an agency response to the petition, FDA said, and not during the advisory committee meeting. FDA also apprised Upjohn (Kaopectate) and Pfizer (Rheaban) of the upcoming advisory committee meeting agenda in letters dated March 11. The agency explained to the firms that, in considering the safety and efficacy of attapulgite and kaolin, the committee will consider "pivotal information" such as two clinical studies on kaolin and pectin submitted by Upjohn in April 1987 and in November-December 1982. However, only study data that deal with kaolin as a single ingredient will be discussed because FDA has determined that "the data do not support the effectiveness of kaolin and pectin in combination," the agency emphasized. Two clinical studies on attapulgite submitted by Pfizer in November 1974 and March 1980 also will be addressed by the committee, as will various documents on oral rehydration solutions. These include a 1990 World Health Organization report on "The Rational Use of Drugs in the Management of Acute Diarrhea in Children" and a 1992 report by the Centers for Disease Control and Prevention titled "The Management of Acute Diarrhea in Children: Oral Rehydration, Maintenance, and Nutritional Therapy." Both documents were cited in the HRG petition in support of oral rehydration. FDA explained in its letters to Pfizer and Upjohn that oral rehydration solutions were not reviewed by FDA during the monograph development process because they were "considered to be medical foods rather than drugs" and are regulated by the agency's Center for Food Safety and Applied Nutrition. Oral rehydration products on the market include Ross' Pedialyte oral electrolyte maintenance solution and Rehydralyte oral electrolyte rehydration solution. In a March 9 letter to FDA Commissioner David Kessler, World Health Organization Diarrheal and Acute Respiratory Disease Control Division Director J. Tulloch, MD, seconded the HRG petition in support of oral rehydration and criticized the approved prescription labeling of J&J's Imodium. "We are particularly concerned that some antidiarrheal drugs marketed in the United States and developing countries are being promoted by their manufacturers as adjuncts to oral rehydration therapy," WHO's Tulloch complained. He maintained that Imodium labeling "goes a step further" when it says that the "use of Imodium does not preclude the administration of appropriate fluid and electrolyte therapy." Tulloch asserted that "this statement conveys to us the message that Imodium should be the first agent used to treat diarrhea in children, but that oral rehydration therapy might also play some role." While ORS treats dehydration "by replacing electrolyte and fluid losses," Tulloch said that WHO does "not feel that the use of Imodium has a significant effect on fluid and electrolyte loss or on the duration and severity of diarrhea." He maintained that the approved labeling "is misleading" because it implies that Imodium is a substitute for oral rehydration therapy. The WHO official also cited a July 1992 letter on Imodium A-D from McNeil to the Medical Lobby for Appropriate Marketing. According to Tulloch, the letter said "it has been standard practice by physicians in the U.S. to use rehydration initially and then to use oral antidiarrheal medications as appropriate." Tulloch said that WHO could not find any pediatric medical textbooks that advocated the use of "antidiarrheal agents for the routine management of acute diarrhea." Tulloch concluded his letter by pointing out that developing countries look to the U.S. FDA when forming their own drug policies. The OTC Drugs Advisory Committee will also address caffeine as an OTC analgesic adjuvant during the April 8 segment of the upcoming meeting. In a March 23 Federal Register notice announcing the April 8-9 meeting, FDA explained that the committee's discussion and recommendations on caffeine as an analgesic adjuvant and kaolin/attapulgite will be considered by the agency as it prepares final monographs for OTC internal analgesic drug products and OTC antidiarrheal drug products, respectively. The OTC Drugs Advisory Committee is slated to begin at 8 a.m. on both April 8 and 9. The meeting will be held in conference rooms D & E of FDA's Parklawn Building, 5600 Fishers Lane, Rockville, Md. In Feb. 25 letters to Bristol-Myers Squibb, McNeil and Whitehall, FDA followed up on earlier communications alerting the firms to the upcoming meeting topic. In the most recent round of communications, FDA outlined to the companies which caffeine/analgesic studies and documents would be considered by the committee at the upcoming meeting, including a series of studies submitted by BMS to FDA in November 1983 and December 1989; studies provided to FDA by McNeil in May and November 1989; and studies by Whitehall that were submitted in March 1989. A study published in the Archives of Internal Medicine and included in Whitehall's 1989 submission, "Caffeine as an Analgesic Adjuvant," is one of two studies conducted by committee consultant Bernard Schachtel, MD, McGill University, that will be considered at the April 8 session. The committee also will review two other published studies on the caffeine issue, as well as the conclusions of the Internal Analgesics panel in 1977, the internal analgesics tentative final monograph, published in November 1988, and the minutes of a Feb. 16, 1989 "feedback" meeting with BMS. The advisory committee meeting also will feature a new industry liaison to the committee, former Norcliff Thayer exec Paul Roberts, MD, whose nomination recently was officially accepted by FDA ("The Tan Sheet" March 1, p.1).