On September 20, 2018, the FDA issued an Animal Drug Safety Communication to alert pet owners and veterinarians about the potential for neurologic adverse events in dogs and cats treated with drugs in the isoxazoline class. The FDA is working with the manufacturers of Bravecto, Nexgard, Simparica and Credelio, all flea and tick products within the isoxazoline class, to include new label information to highlight the potential for neurologic adverse events including muscle tremors, ataxia and seizures, because these events were consistently seen across the isoxazoline class. The FDA reports it “carefully reviewed studies and other data on Bravecto, Credelio, Nexgard and Simparica prior to approval, and these products continue to be safe and effective for the majority of animals”. The label changes to highlight the potential for neurologic adverse reactions are requested to allow pet owners and veterinarians to make treatment decisions for each pet on an individual basis. The potential for adverse neurologic reactions has been identified on package inserts from all companies since approval of the products by the FDA. Many current news articles and posts regarding this FDA communication are presenting these risks as new information or these products as dangerous. Please read the FDA announcement. The information is not new. The request is to highlight the risks. All products remain fully FDA approved and are considered by the FDA to be both safe and effective for the majority of pets. As with any product, if a particular pet has a medical condition rendering him or her more susceptible to an adverse reaction or if a pet simply has an adverse reaction, that pet should receive alternative options. Fleas and ticks are not simply nuisances. They are vectors of disease for both our patients and ourselves. Failure to adequately control fleas and ticks can have devastating health consequences for both ourselves and our pets. The takeaway from the FDA communication is highlighting a known and acknowledged risk, not abandonment of a class of drugs which has offered many of us a safe and effective way to protect our pets and ourselves.
The safety information below is copied verbatim from each company’s website homepage.
From the Bravecto website: [https://us.bravecto.com]
IMPORTANT SAFETY INFORMATION:
Bravecto has not been shown to be effective for 12-weeks’ duration in puppies or kittens less than 6 months of age. Bravecto Chew: The most common adverse reactions recorded in clinical trials were vomiting, decreased appetite, diarrhea, lethargy, polydipsia, and flatulence. Bravecto is not effective against lone star ticks beyond 8 weeks of dosing. Bravecto Topical Solution for Dogs: The most common adverse reactions recorded in clinical trials were vomiting, hair loss, diarrhea, lethargy, decreased appetite, and moist dermatitis/rash. Bravecto is not effective against lone star ticks beyond 8 weeks of dosing. For topical use only. Avoid oral ingestion. Use caution in dogs with a history of seizures. Seizures have been reported in dogs receiving fluralaner, even in dogs without a history of seizures. Bravecto Topical Solution for Cats: The most common adverse reactions recorded in clinical trials were vomiting, itching, diarrhea, hair loss, decreased appetite, lethargy, and scabs/ulcerated lesions. Bravecto is not effective against American dog ticks beyond 8 weeks of dosing. For topical use only. Avoid oral ingestion. The safety of Bravecto has not been established in breeding, pregnant and lactating cats. Use with caution in cats with a history of neurologic abnormalities. Neurologic abnormalities have been reported in cats receiving Bravecto, even in cats without a history of neurologic abnormalities.
From the Simparica website: [https://www.simparica.com]
IMPORTANT SAFETY INFORMATION:
Simparica is for use only in dogs, 6 months of age and older. Simparica may cause abnormal neurologic signs such as tremors, unsteadiness, and/or seizures. Simparica has not been evaluated in dogs that are pregnant, breeding or lactating. Simparica has been safely used in dogs treated with commonly prescribed vaccines, parasiticides and other medications. The most frequently reported adverse reactions were vomiting and diarrhea. See full Prescribing Information.
From the Credelio website: [https://www.credelio.com]
IMPORTANT SAFETY INFORMATION FOR CREDELIO
The safe use of Credelio in breeding, pregnant or lactating dogs has not been evaluated. Use with caution in dogs with a history of seizures. The most frequently reported adverse reactions are weight loss, elevated blood urea nitrogen, excessive urination, and diarrhea. See package insert for full safety information.
From the Nexgard website: [https://nexgardfordogs.com/Pages/About.aspx]
IMPORTANT SAFETY INFORMATION:
Reported side effects include vomiting, itching, diarrhea, lethargy and lack of appetite. The safe use of NexGard in pregnant, breeding or lactating dogs has not been evaluated. Use with caution in dogs with a history of seizures. See your veterinarian for more information.
FDA Communication:
Animal Drug Safety Communication: FDA Alerts Pet Owners and Veterinarians About Potential for Neurologic Adverse Events Associated with Certain Flea and Tick Products