Efficacy of Protamine Zinc Recombinant Human Insulin for Controlling Hyperglycemia in Dogs with Diabetes Mellitus

Background: Alternative insulin preparations are needed when NPH insulin is ineffective in diabetic dogs. This study evaluated the efficacy of recombinant human protamine zinc insulin (rhPZI) for treating diabetic dogs. Hypothesis: rhPZI is effective for treating diabetic dogs. Animals: Six newly diagnosed and 11 insulin-treated diabetic dogs. Methods: Prospective clinical trial. Dogs were treated with rhPZI for 60 days. Control of glycemia was assessed on days 7, 14, 30, and 60 by evaluation of history, physical examination, body weight, serum fructosamine concentration, and blood glucose concentrations measured before and 2, 4, 6, 8, and 10 hours after rhPZI administration. Adjustments in dosage of rhPZI were made as needed to control glycemia. Results: rhPZI administration resulted in a significant decrease in 10-hour mean blood glucose (MBG(10h); 299 +/- 115 versus 457 +/- 38 mg/dL, X +/- SD, P = .0003) and serum fructosamine (478 +/- 83 versus 557 +/- 104 mu mol/L, P = .006) concentration at day 60, compared with day 1, respectively. By day 60, polyuria and polydipsia had improved in 14, body weight was stable or increased in 16, MBG(10h) had decreased in 16, and serum fructosamine concentration had decreased in 11 of 17 dogs, compared with day 1. Hypoglycemia (< 80 mg/dL) was the only consistent adverse event. Conclusions and Clinical Relevance: rhPZI is effective in diabetic dogs and can be considered as an alternative treatment in diabetic dogs that are poorly controlled using other insulin preparations.