Winn Feline Foundation Progress Report
By Susan Little DVM, Diplomate ABVP (Feline)
Pharmacokinetics of Metformin in Healthy Cats
Investigators: D. Spann, R. Nelson, R. Vulliet, A. Brondos
University of California, Davis, CA
Metformin (Glucophage®, Hoechst Marion Roussell) is an oral medication used to control type-2 diabetes mellitus in humans. Since the feline form of diabetes is similar to type-2 diabetes in humans in many ways, a study was designed to evaluate the use of metformin as an oral treatment for diabetes in cats. Few oral medications have been evaluated for the control of diabetes in cats. Currently, most feline diabetics are controlled with insulin injections.
The study consisted of three parts: an evaluation of the pharmacokinetics of a single dose of metformin in healthy cats, a three-week trial of the potential toxicity of metformin in healthy cats, and a clinical trial of metformin in diabetic cats. Several conclusions were drawn from the results of this research. Doses of metformin over 25 mg once or twice daily were associated with loss of appetite, weight loss, and vomiting. The drug did not produce any changes in complete blood cell counts or serum biochemistries. A target dose of 25 to 50 mg per cat twice daily was identified for the treatment of diabetes. When used in diabetic cats, however, the drug failed to show promise for control of diabetes. While the results of the research were disappointing, only by studying all potential drugs for the treatment of feline diabetes will new and valuable options come to light.
For further information:
Spann, D., R. Nelson, et al. (2000). Evaluation of metformin in healthy and diabetic cats (abstract 69). Proc 18th Amer Coll Vet Intern Med Forum, Seattle, WA.