Kaopectate, the over-the-counter diarrhea treatment for humans, recently has been reformulated to contain an aspirin derivative that is toxic to cats in high doses.
Kaopectate's new formula contains bismuth subsalicylate, which may cause salicylate toxicosis in cats if they are overdosed. Previously, the product contained attapulgite, an inert clay aluminum. The original kaolin pectin formula of Kaopectate was replaced by the attapulgite formula in caplets in 1984, and liquid attapulgite formulations were first introduced in 1989.
The attapulgite formulation of Kaopectate caplets may still be available. According to a Pfizer Animal Health spokesman, the new formulation of all liquid forms of Kaopectate began shipping in December 2002. Reformulated caplets are scheduled to begin shipping no later than April 2004.
Though it is an extralabel use, for decades, veterinarians have recommended Kaopectate to treat diarrhea in cats and dogs, particularly for clients who call after hours or are unwilling or unable to get immediate veterinary care, said Dr. Cory Langston, a diplomate of the American College of Veterinary Clinical Pharmacology and a member of the AVMA Council on Biologic and Therapeutic Agents. Dr. Amy Neal at U.S. Pharmacopeia, an organization that provides drug information and runs a medication errors reporting system, alerted Dr. Langston about the formulation change.
"This (product) was prescribed, perhaps in part, because it could do no harm, since none of the ingredients were absorbed orally. Because of this safety factor, large and frequent doses were commonly used." Dr. Langston said. "Unlike the old Kaopectate, this new formulation could result in toxicosis if you don't account for the salicylate content of the product."
Dr. Steve Hansen, a diplomate of the American Board of Veterinary Toxicology and director of the American Society for the Prevention of Cruelty to Animals' Animal Poison Control Center, said the range of recommended aspirin-derivative dosages that have been published for cats is 10 mg/kg every other day to 25 mg/kg every day.
A tablespoon of reformulated children's or regular-strength Kaopectate contains 130 mg aspirin equivalent, and extra-strength Kaopectate contains 230 mg aspirin equivalent. A tablespoon of extra-strength Kaopectate given to a 5-pound cat would yield 120 mg/kg aspirin equivalent and would likely result in toxicosis, according to Dr. Hansen.
"Cats typically don't metabolize and excrete many compounds, including aspirin, efficiently, which means we're much more likely to have effects," Dr. Hansen said.
For more information on managing poisons and poison prevention, visit the ASPCA's Poison Control Center Web site, www.apcc.aspca.org.