Fort Dodge Animal Health, of Overland Park, Kansas, at FDA's request,
has agreed to immediately cease production and recall its heartworm
medication ProHeart®6 from the market until the FDA's concerns about
adverse reaction reports associated with the product can be resolved.
FDA is requesting that the firm continue to conduct research to
determine the cause of related adverse reactions and develop a strategy
to help prevent such problems in the future before the product is
marketed again. The FDA will convene an independent scientific advisory
committee to thoroughly evaluate all available data.
ProHeart®6 is an approved injectable sustained-release heartworm
prevention product for dogs. Heartworm disease is a serious and
potentially fatal condition of dogs, cats, and other species of mammals.
The parasite that causes heartworm disease is transmitted through the
bite of a mosquito.
FDA is also advising veterinarians to avoid administering this
product to dogs until further notice. Pet owners should consult their
veterinarians regarding their pet's health care needs.
Since the product was approved in June 2001, Fort Dodge Animal Health
has cooperated with FDA to investigate numerous adverse event reports.
As a result, Fort Dodge has voluntarily changed the label to include
post approval safety information including rare reports of death and a
caution to practitioners that dogs should have a negative test for
heartworm before administration.
Despite these label changes, FDA is still receiving unexplained
adverse event reports, some of them severe. FDA's concern is based on
voluntary self-reporting to FDA by veterinarians and owners whose dogs
have suffered adverse drug experiences (ADEs) to ProHeart®6 (which
contains the drug moxidectin) as well as the mandatory reporting of
adverse events by Fort Dodge Animal Health.
Fort Dodge Animal Health has agreed to recall any product that has
already been distributed to veterinarians.
As of August 4, 2004, FDA's Center for Veterinary Medicine (CVM) had
received 5,552 adverse event reports for ProHeart®6. The actual number
of adverse events is likely even higher because studies show that only a
fraction of actual ADEs are reported.
The Agency has observed an increase in the number of cases associated
with liver and bleeding abnormalities followed in some cases by death.
