Today the U.S. Food and Drug Administration (FDA) Center for Veterinary
Medicine (CVM) is announcing that it has received reports of adverse
reactions in dogs receiving the drug Comfortis® (spinosad) concurrently with
high, extra-label doses of the drug ivermectin. The clinical signs of these
adverse reactions are consistent with ivermectin toxicity.
Comfortis® (spinosad), manufactured by Elanco Animal Health, a division of
Eli Lilly and Company, is a monthly oral, chewable tablet used for the
prevention and treatment of flea infestations on dogs. Veterinarians who use
high, extra-label doses of ivermectin to treat dogs with non-responsive
demodectic mange and other conditions should be aware that some dogs
have developed signs of ivermectin toxicity when ivermectin is used
concurrently with Comfortis® (spinosad).
CVM and Elanco Animal Health are advising veterinarians that dogs
receiving extra-label doses of ivermectin should not receive concurrent
treatment with Comfortis® (spinosad).
CVM is working with Elanco Animal Health as they address this issue.
Additional information regarding this safety warning can be obtained on the
Elanco Animal Health website.
Lilly Companion Animal Health Technical Bulletin: Spinosad and the Extra-
Label Use of High Dose Ivermectin for the Treatment of Generalized
Demodicosis in Dogs - http://elms.xh1.lilly.com/10788_03_tech_Bulletin .pdf
