The Food and Drug Administration announced June 5 the limited reintroduction of ProHeart 6 to the U.S. veterinary market. The injectable canine heartworm medication had been voluntarily recalled in 2004 after the FDA Center for Veterinary Medicine raised serious questions about the drug's safety.
The agency is allowing the drug's limited return to the veterinary market as part of a risk minimization and restricted distribution program designed to manage the re-introduction of ProHeart 6 to provide for safe, appropriate use of the product while minimizing risk to dogs.
"This is the first veterinary drug to be marketed under a risk minimization and restricted distribution program. Numerous drugs for use in people have been successfully marketed under similar programs," said Dr. Bernadette Dunham, director of the FDA-CVM. "While we concur with the limited return of ProHeart 6 to the U.S. market, we strongly encourage veterinarians and pet owners to report any possible adverse reactions."
The risk minimization and restricted distribution program is intended to educate veterinarians and pet owners regarding the possible risks associated with the use of ProHeart 6. Therefore, Fort Dodge is requiring veterinarians who wish to purchase ProHeart 6 to register with the company and participate in a Web-based training program prior to obtaining the product.
The program first aired on the Web in June and can still be viewed at www.vetsymposium.com/proheart6. Training and registration must be completed before the product will be shipped to a practitioner. For additional information, veterinarians should call their Fort Dodge sales representative or call the company's Professional Services department at (800) 533-8536.
The return of ProHeart 6 to the market is based on results of additional toxicologic and pharmacologic studies by Fort Dodge coupled with the low adverse reaction frequency in international markets, according to the FDA.
In 2004, Fort Dodge agreed to voluntarily recall the product from the market on the basis of the FDA's concerns regarding reports of serious adverse reactions in dogs following the use of ProHeart 6 (see JAVMA, Oct. 15, 2004, page 1157). In response to the agency's concerns, the manufacturer conducted additional testing of its product, which indicated that residues of the solvents used in the manufacture of ProHeart 6 may cause allergic reactions.
"This is the first veterinary drug to be marketed under a risk minimization and restricted distribution program. Numerous drugs for use in people have been successfully marketed under similar programs. While we concur with the limited return of ProHeart 6 to the U.S. market, we strongly encourage veterinarians and pet owners to report any possible adverse reactions."
—DR. BERNADETTE DUNHAM,
DIRECTOR, FOOD AND DRUG ADMINISTRATION CENTER FOR VETERINARY MEDICINE
The manufacturer has improved the manufacturing specifications for ProHeart 6 to decrease the presence of those residues and has marketed the product in international markets. Few adverse events have been reported with this reformulated product.
"We are extremely pleased to bring ProHeart 6 back to veterinarians and pet owners throughout the United States, as it has safely and effectively protected millions of dogs around the world against potentially deadly heartworm disease," announced Dr. Rami Cobb, senior vice president of pharmaceutical research and development for Fort Dodge. "Our first and foremost priority continues to be providing products that help ensure the health and well-being of all animals.
"At the time of the voluntary U.S. recall in 2004, we believed it was in the best interest of veterinarians and pet owners to thoroughly address the concerns of the CVM before continuing the marketing of this product in the United States. We have always maintained our confidence in ProHeart 6 and the unique medical benefits it brings to veterinary medicine. Fort Dodge has worked with the CVM to address its questions, and feels the scientific data, as well as our vast experience with the product internationally, supports confidence in the product and its return to the U.S. market."
The ProHeart 6 label and Client Information Sheet have been revised to include updated safety information. The new label includes warnings not to administer the drug within one month of vaccinations and to use the product with caution in dogs with pre-existing allergic diseases including food allergies, allergic hypersensitivity, and flea-bite allergy dermatitis. The label also warns against administering the drug to dogs that are sick, debilitated, underweight, or have a history of weight loss. In addition, the label's Post-Approval Experience section has been updated to include information about adverse reactions based on voluntary postapproval drug experience reporting.
Dog owners who suspect their dog is experiencing an adverse reaction to ProHeart 6 should immediately contact their veterinarian to initiate appropriate veterinary care. Veterinarians should contact Fort Dodge Animal Health to report any adverse events at (800) 533-8536.