January 29, 2016
The U.S. Food and Drug Administration has issued warning letters to six manufacturers of unapproved levothyroxine sodium drugs for hypothyroidism in dogs. These unapproved products have not been reviewed by the FDA for safety and effectiveness.
Thyro-Tabs Canine (levothyroxine sodium tablets), (NADA 141-448) is the only FDA-approved drug for replacement therapy for diminished thyroid function (commonly known as hypothyroidism) in dogs.
FDA is concerned about unapproved animal drugs. Animal drugs that have not been reviewed and approved by FDA may not meet FDA’s strict standards for safety and effectiveness. They also may not be properly manufactured or labeled.
FDA issued warning letters to manufacturers of the following unapproved levothyroxine products:
- Thyroid Chewable Tablets
- Thyroxine L
If the companies that were issued the warning letters continue to market the violative products, they may be subject to enforcement action, including seizure of violative products and/or an injunction.
Shipments of levothyroxine active pharmaceutical ingredient (API) not referenced in an approved animal drug application or the subject of an index listing or a valid investigational use exemption and unapproved finished animal drugs containing levothyroxine offered for import may be subject to refusal.
Dog owners and veterinarians can report to the FDA any adverse events, including ineffectiveness, in dogs that received approved or unapproved hypothyroidism products. Information on reporting adverse events can be found at: http://www.fda.gov/animalveterinary/safetyhealth/reportaproblem/ucm055305.htm.
- Neogen Corporation
- Quality Animal Care Manufacturing
- Virbac Animal Health, Inc.
- Dechra Veterinary Products LLC
- Diamond Animal Health Inc.
- Merck Animal Health
- Dear Veterinarian Letter - THYRO-TABS CANINE (levothyroxine sodium tablets)
- More information on FDA’s concerns regarding unapproved animal drugs
- Information on how to tell if a drug is FDA-approved for animals
From an Idea to the Marketplace: The Journey of an Animal Drug through the Approval Process Hypothyroidism in Dogs—There’s now an FDA-Approved Treatment