Diarrhea: Sweeping Changes in the OTC Market

W. Steven Pray, PhD, DPh; Joshua J. Pray, PharmD candidate


US Pharmacist. 2005;30(1) 

In This Article

The 2003 Antidiarrheal Final Rule

In 2003, the FDA published its final rule on antidiarrheals, finishing the cycle begun 28 years earlier.[3] The agency's conclusions were ground breaking and affect pharmacist triage decisions for patients with diarrhea. The report became effective April 19, 2004. The following discussion of antidiarrheal ingredients is based on the 2003 final rule.

Bismuth subsalicylate (Pepto-Bismol, Kaopectate) was given a Category III designation in 1986 (insufficient proof of efficacy and/or safety) but was found safe and effective in the treatment of acute nonspecific diarrhea in the 2003 document. Four clinical studies were submitted in support of this labeling and were accepted by the FDA. The agency also examined labeling for bismuth subsalicylate for travelers' diarrhea but asked for further research, stating that it would amend the final rule if the ingredient was proven safe and effective for travelers' diarrhea. FDA requested that companies not include travelers' diarrhea labeling on bismuth subsalicylate packages unless an amended final monograph appears.

All bismuth subsalicylate products must carry the Reye's syndrome caution: "Warning: Children and teenagers should not use this medicine for chicken pox or flu symptoms before a doctor is consulted about Reye's syndrome, a rare but serious illness reported to be associated with aspirin." The new label of bismuth subsalicylate products also must suggest that patients younger than 12 years ask a doctor before use because of a lack of studies to prove efficacy in those ages. Prior to the recent relabeling, bismuth products were labeled for children as young as 3 years.

The 2003 final rule found kaolin safe and effective as a single ingredient. It carries labeling stating that it helps firm stools within 24 to 48 hours. At present, no major product contains kaolin as the sole active ingredient.

The FDA also explored attapulgite in the final rule. Manufacturers had been put on notice that the ingredient might be given nonmonograph status as of 1993, unless additional studies were done. The agency received none, and in the 2003 document, attapulgite was given nonmonograph designation.

Upon publication of the 2003 document, the FDA revealed that in 1993 it had examined the studies cited in support of polycarbophil and calcium polycarbophil and found them inadequate for proving efficacy for acute nonspecific diarrhea. The manufacturers had been notified of the pending decision in 1994 but had not chosen to take any action. As a result, the ingredients were judged nonmonograph in 2003.

Loperamide was unaffected by the 2003 FDA rule, as it was approved through NDA-related processes. Thus, the labeling regarding age remains the same as it was, with recommended dosing in people as young as 6 years.


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