OTC reformulations can hold hidden dangers

Dr. Dawn Boothe

When commonly used over-the-counter drugs (OTC) are reformulated, the ingredient changes can go unnoticed and lead to adverse reactions in some patients.

Formulated for human use, Kaopectate® has long been used as a stopgap measure by veterinarians for cats and dogs suffering an occasional bout of diarrhea. But the product has been reformulated as bismuth subsalicylate and could pose a danger to the animals.

It can still be safe to use, said Dawn Boothe, DVM, PhD, but veterinarians and their staffs need to be aware of the levels of salicylate in the product. Veterinarians also have prescribed Pepto-Bismol® (also bismuth subsalicylate) in the past for the same purpose, she said, but they were able to indicate the proper dosage since they were aware of the ingredients. Even with the changes in Kaopectate®, veterinarians can safely prescribe specific dosages of the children’s or regular formulas, Boothe said, but they need to make sure the pet owner is not using the extra-strength formulas.

Reformulating an OTC is a fairly simple and common process, Boothe noted, and companies probably don’t need FDA approval if the new formula is already approved and used under a different brand name.

“My biggest concern is people might not be aware of the changes,” Boothe said. “Veterinarians need to be aware that the active ingredients (in OTC drugs) can be changed with little fanfare, and they need to train pet owners to read the labels.”

The Kaopectate® brand was purchased by Pfizer in April. The complete ingredient list and label warnings are available on the Pfizer website.