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 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.
"For decades, veterinarians have recommended Kaopectate to treat diarrhea in cats and dogs", said Dr. Cory Langston, a diplomate of the American College of Veterinary Clinical Pharmacology and a member of the AVMA (American Veterinary Medical Association) Council on Biologic and Therapeutic Agents.
"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 do not account for the salicylate content of the product."
Dr. Steve Hansen, a diplomate of the American Board of Veterinary Toxicology and director of the ASPCA's (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 reformulatedextra-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 do not metabolize and excrete many compounds, including aspirin, efficiently, which means we are much more likely to have effects," Dr. Hansen said. Dogs that may have an allergy to aspirin should not be given the new formulation. Also, those dogs that are taking aspirin, steroids, or another non-steroidal anti-inflammatory drug (NSAID) such as Rimadyl, EtoGesic, or Deramaxx should not be given the new formulation.