Preliminary study of protamine zinc recombinant insulin for the treatment of diabetes mellitus in cats.

The efficacy of a new protamine zinc formulation based on recombinant insulin (PZIR) was compared with a veterinary-approved beef/pork-source insulin (PZI VET, Idexx Pharmaceuticals) that has been shown to significantly decrease blood glucose in cats with diabetes mellitus (DM). After being examined and weighed and having blood collected for determination of serum fructosamine concentrations, 50 cats with DM and stable glycemic control on PZI VET were switched to PZIR for 30 days at the same dose rate and interval. There was only one reported episode of hypoglycemia, and the cat was withdrawn from the study. In the 47 cats completing the study, there were no significant differences in body weight or serum fructosamine concentrations at days 15 or 30 compared with day 0. The results of this study indicate that PZIR provides glycemic control that is comparable to that of PZI VET when used at the same dose and dosing interval.