FDA warns pet owners about fluorouracil risks

The FDA reminded veterinary professionals, pharmacists, other healthcare professionals, and pet owners of the serious risks pets have when exposed to the FDA-approved prescription topical medical 5-fluorouracil (fluorouracil). Currently, there have been no reports of cats with fluorouracil poison, but cats are likely to be very sensitive to this drug.

“As of September 2022, the FDA had received 14 reports involving 20 dogs that had been accidentally exposed to fluorouracil,” stated Juli Putnam, a spokesperson for the FDA Center for veterinary medicine, in an organizational release.¹

“It’s important to note that every event reported to FDA ended in death of the dog, even when only a small amount of drug was ingested. Also, because consumers and veterinarians may not always report these incidents to the drug manufacturer or FDA, we are concerned that the actual number of exposures and deaths could be higher. That’s why we also worked with the drug sponsors to include information about the hazard of pet exposure in the new labeling," she continued.

According to the release, the drug is applied to the skin to treat various conditions such as superficial basal and squamous cell carcinomas, vitiligo, and warts and is marketed as Carac, Efudex, Fluoroplex, Tolax, and the generic name fluorouracil cream, 5%.¹ Nearly all cases of pets exposed to this drug are accidental and occur when the pet chews on the medications tube. However, pets can also be exposed if they lick the skins of someone who applied the medication

The signs of fluorouracil poisoning include:

• Vomiting
• Seizure
• Tremors
• Difficulty breathing
• Decreased activity
• Diarrhea
• Death (without prompt treatment)

The FDA asked the manufacturers of topical fluorouracil to add the following warning on the containers: “May be fatal if your pet licks or ingests. Avoid allowing pets to contact this tube or your skin where [name of specific fluorouracil product] has been applied. Store and dispose out of the reach of pets.”¹ The FDA will continue to monitor reports of pets exposed to topical fluorouracil products while encouraging veterinarians and health care providers to report adverse events in pets associated with these products or any drug for people and animals.

Reference

FDA warns that topical drug for humans can be deadly to pets. News release. American Veterinary Medical Association. September 28, 2022. Accessed September 29, 2022. https://www.avma.org/news/fda-warns-topical-drug-humans-can-be-deadly-pets