Department of Health and Human Services
Public Health Service
Rockville, MD 20857
August 14, 2006
VIA CERTIFIED MAIL, RETURN RECEIPT REQUESTED
Director, Regulatory Affairs
3239 Satellite Blvd
Duluth, GA 30096
Ref. No. NADAs 140-971, 140-886, 138-412 & 141-078
RE: Heartgard® (ivermectin) and Heartgard® Plus (ivermectin/pyrantel); sponsor websites:
Dear Ms Skibo:p>
We, the Division of Surveillance (DOS), Center for Veterinary Medicine, have reviewed several promotion materials on your website for Heartgard® Plus (ivermectin/pyrantel) Chewables for Dogs, NADA 140-971, Heartgard® (ivermectin) Chewables for Dogs, NADA 140-886, Heartgard® (ivermectin) Tablets for Dogs NADA 138-412, and Heartgard® (ivermectin) Chewables for Cats, NADA 141-078. These promotional pieces contain claims that are false or misleading causing the drugs to be misbranded under sections 502(a) [21 USC 352 (a)] and 201 (n) [21 USC 321(n)] of the Federal Food, Drug, and Cosmetic Act (the Act).
Heartgard® Plus is an oral chewable formulation containing ivermectin and pyrantel. It is approved for the prevention of canine heartworm disease by eliminating the tissue stage of heartworm larvae (Dirofilaria immitis) for a month (30 days) after infection and for the treatment and control of ascarids (Toxocara canis, Toxocaris leonina) and hookworms (Ancylosotoma caninum, Uncinaria stenocephala, Ancylostoma braziliense). It is intended to be given to dogs monthly.
Heartgard® Chewables and Heartgard® Tablets are oral formulation for dogs containing ivermectin. They are approved for the prevention of canine heartworm disease by eliminating the tissue stage of heartworm larvae (Dirofilaria immitis) for a month (30 days) after infection. These products are also intended to be given to dogs monthly.
Heartgard® Chewables for Cats are an oral chewable formulation for cats containing ivermectin. They are approved for prevention of feline heartworm disease by eliminating the tissue stage of heartworm larvae (Dirofilaria immitis) for a month (30 days) after infection, and for the removal and control of adult and immature hookworms (Ancylostoma tubaeforme and A. braziliense). This product is intended to be given to cats monthly.
In a letter dated August 24, 2005, we requested that you stop claiming 100% effectiveness for heartworm prevention. As you know, this request was based on the post-approval adverse drug event (ADE) reports we have received for lack of effectiveness for heartworms prevention.
In a letter dated September 30, 2005, you agreed to immediately discontinue promotion and advertising 100% effectiveness for your heartworm prevention products. We agreed to continue monitoring heartworm preventive lack of effectiveness reports and to consider requesting you to revise your product labels to reflect these reports at a later date. In another letter dated May 5, 2006, you agreed to correct all promotional claims of 100% effectiveness for your heartworm preventive products that were inadvertently overlooked. Notwithstanding those assurance, some of your promotional materials still contain such statements. For example, you website: (us.merial.com/pet_owners/products.asp) claims: "Heartworm disease is 100% preventable with HEARTGARD, satisfaction guaranteed!" This statement implies that if the product is taken as directed, it will provide 100% prevention from heartworm disease. Furthermore, the Merial sponsored Veterinary Bulletin article entitled "Comparing HEARTGARD® Plus (ivermectin/pyrantel) & Milbemycin Oxime" that is on your website claims: HEARTGARD ® Plus is 100% effective against Dirofilaria immitis.…" and "HEARTGARD® Plus is 100% effective against heartworms…" It also includes the statements. "When given according to label directions, HEARTGARD and HEARTGARD Plus have consistently proved 100% prevention of heartworm disease in all studies," and "This unequaled spectrum of efficacy continues month after month, dose after dose, providing the confidence you need when prescribing a monthly broad-spectrum heartworm preventative for your patient. HEARTGARD Plus is 100% effective against heartworms.…" Additionally, the Veterinary Bulletin article on your website entitled " HEARTGARD® Plus (ivermectin/pyrantel) and Preweaning Protection in Puppies" claims "From the very first dose, HEARTGARD® Plus is 100% effective against heartworms.…"
Given the lack of effectiveness (heartworm prevention) ADEs reported for your products, the promotion of "100% effectiveness for prevention of heartworm disease" is false or misleading and causes your product to be misbranded within the meaning of section 502(a) [21 USC 352(a)] of the Act.
Conclusion and Requested Action
As discussed above, the claims made in these promotional material are false or misleading and cause the drugs to be misbranded under section 502(a) [21 USC 352(a)] of the Act.
The Division of Surveillance request that Merial immediately cease the dissemination of violative promotional materials for Heartgard and Heartgard Plus such as those described above. Specifically, you should correct the promotional materials on your website concerning Heartgard and Heartgard® Plus and other materials that may contain similar information. Future promotional materials should adequately address the claims of heartworm prevention, without overstating the effectiveness, to reflect the reported adverse drug events associated with the products. Because the violations described above are serious, further, we request that your submission include a comprehensive plan of action to disseminate a truthful, non-misleading, and complete corrective message about the issue discussed in this letter to the audience(s) that received the violative promotional materials. Please direct your written response to me at the Food and Drug Administration, Division of Surveillance, HFV-210, 7519 Standish Pl, Rockville, MD 20855. We remind you that only written communications are official.
The violations discussed in this letter do not necessarily constitute an exhaustive list. It is your responsibility to ensure that your promotional materials for Heartgard® and Heartgard® Plus, as well as other Merial Limited products, comply with the requirements of the Act and its implementing regulations.
Failure to correct the violations discussed above may result in FDA regulatory action, including seizure or injunction, without further notice.
Lynn O. Post, DVM, PhD, DABVT
Director, Division of Surveillance
This page was posted on February 12, 2008.