The U.S. Food and Drug Administration’s Center for Veterinary Medicine announced today the approval of ProZinc (protamine zinc recombinant human insulin) for managing diabetes mellitus in dogs. This product has not been evaluated for use in people.

ProZinc is already approved for use in cats, and veterinarians have used the product in dogs prior to the approval under extralabel use (also called “off-label” use, because the use is not listed on the approved label). With today’s approval, the FDA has determined that ProZinc is safe and effective in reducing hyperglycemia (high blood sugar) and associated clinical signs in dogs with diabetes mellitus.

Insulin is a hormone that helps glucose, a sugar that is the body’s main source of energy, get into the body’s cells. In dogs with diabetes mellitus, the pancreas does not produce enough insulin, so glucose is unable to get into the body’s cells and is instead passed out of the body in the urine. Left untreated, diabetes mellitus can damage the liver, kidneys and/or eyes; increase the risk of infections; and slow the healing of wounds. It can also lead to diabetic ketoacidosis, a serious and life-threatening metabolic condition.

Dogs with diabetes mellitus require careful veterinary management to reach and maintain the appropriate level of insulin replacement. The FDA recognizes the veterinary medical challenges associated with managing diabetic dogs and defers to the veterinarian’s clinical judgement on which FDA-approved insulin drug product is appropriate for use in their canine patients. The FDA strongly encourages use of an FDA-approved animal insulin drug product for newly-diagnosed dogs, or when transitioning dogs from one product to another. In addition to ProZinc, Vetsulin (porcine insulin zinc suspension) is also approved for use in dogs.

The FDA cautions veterinarians and pet owners about the use of unapproved, compounded insulin products, which have not been evaluated for safety and effectiveness. These unapproved products may vary in quality and potency, which can complicate veterinary medical management of the disease. Manufacturing of insulin products is particularly challenging due to stability, sterility, and pH issues. In addition, FDA-approved products have been evaluated to confirm that they are properly manufactured. After FDA approval, the agency also continues to monitor the safety, efficacy, and manufacturing of the drug. Safety monitoring includes the evaluation of post-approval adverse reactions. Unapproved drugs, including compounded drugs, do not undergo the same preapproval and post-approval evaluations.

ProZinc must be prescribed by a licensed veterinarian because a trained professional is needed to correctly diagnose and manage diabetes mellitus and determine if ProZinc is an appropriate treatment. ProZinc should not be used in dogs that are sensitive to protamine zinc recombinant human insulin or any other ingredients in ProZinc. It should not be used during episodes of hypoglycemia (low blood sugar). The most common adverse reactions in dogs taking ProZinc were lethargy, anorexia, hypoglycemia, vomiting, seizures, shaking, diarrhea, and ataxia.

ProZinc is available in 10 mL multi-dose vials at a concentration of 40 international units/mL and is manufactured by Boehringer Ingelheim Animal Health USA Inc.