FDA Addresses Continued Shortage of Drug Used to Treat Heartworm Infection in Dogs

The Food and Drug Administration announced today that it will continue to allow Merial to import limited quantities of Immiticide (melarsomine dihydrochloride) from the company’s European supplier in order to address an ongoing shortage of the FDA-approved drug in the United States. A small amount of U.S.-manufactured Immiticide is also available.

The quantities of Immiticide that the European supplier can import and that the U.S. supplier recently manufactured will satisfy only a fraction of the U.S. demand. As a result, FDA and Merial ask veterinarians to conserve these limited supplies by using the drug only for dogs in most urgent need of treatment.

There has been a continued shortage of U.S.-produced Immiticide since 2011, due to technical difficulties faced by the U.S. supplier of the drug. The approved supplier for U.S. markets will close its facility by the end of this year. FDA continues to allow the drug to be imported from the European supplier while Merial works out technical issues for manufacturing Immiticide for use in the U.S.

Veterinarians should be aware that the U.S.- and European-produced Immiticide products have different expiry lengths, and they should observe the expiration date on the labeling.

The U.S.-produced Immiticide has a shorter than normal period before expiration while imported Immiticide has a normal expiry length. However, the packaging of the imported product is formatted for use in other countries and meets the regulatory requirements of those countries. Therefore, Merial will provide a copy of the U.S. Immiticide Package Insert with each shipment. Veterinarians should follow the insert’s prescribing information.

Veterinarians will only be able to obtain Immiticide directly from Merial through a restricted distribution program. They will not be able to purchase the drug through Merial’s distributors for stocking their clinic inventories.

Additional details on Merial’s temporary measures to address the Immiticide shortage can be found in the company’s recent “Dear Doctor” letter to U.S. veterinarians.