COMFORTIS® and ivermectin (safety warning) - Page 1

COMFORTIS® and ivermectin (safety warning)

  http://www.fda.gov:/cvm/CVM_Updates/ComfortisSafety.htm

June 24, 2008

COMFORTIS® and ivermectin interaction Safety Warning Notification

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
 

I am planning on switching to comfortis. I have been using Frontline Plus and it does not seem to be effective any more.

I have heard this same complaint from others. No fleas to be seen but regular scratching. My vet gave me antihistamines but no effect-I really do not think my pup has allergies. Usually, if I am around a dog with fleas, I get bitten and I am not.

A friend who has two elderly Tibetans who were itching but no fleas, swiched from Frontline Plus to Comfortis three months ago. No more itching and no side effects.

Is anyone else using it?

My pup is on the regular dose of heartguard plus. I think that just to be safe, I will use the comfortis around the 15th and the heartguard on the 1st of the month.

Michele and Pharaoh