A New Modified Protamine Zinc Insulin: Comparison With Histone Zinc Insulin, Clear, and Standard Protamine Zinc Insulins 12

Patients with diabetes who require more than 40 units of insulin per day are usually best con- trolled by giving a large dose of protamine zinc insulin and a smaller dose of regular (or crystalline) insulin, before breakfast, daily (1).Stand- ard protamine zinc insulin does not have sufficient rapid activity to control the hyperglycemia occurring after meals in patients with severe dia- betes.In such cases, attempts to eliminate glycosuria during the day by increasing the dose of protamine zinc insulin tend to cause hypoglycemia during the night.When the diabetes is mild, re- quiring 40 units or less per day, the rise in the blood sugar after food intake may not be great, and a single dose of protamine zinc insulin daily may permit good regulation.A night feeding at 9 or 10 p.m. helps to prevent nocturnal hypogly- cemia.Among 154 patients satisfactorily regu- lated during the period between January 1, 1940, and July 1, 1942, we found that "combined ther- apy," with separate daily injections of protamine zinc insulin and regular insulin, was necessary in 57 cases (37 per cent).In the period of 21/2 years, the average dose given the 97 patients re- quiring protamine zinc insulin alone was 24 units, while the average total daily requirement of the 57 patients needing combined therapy was 57 units.Of the 54 patients requiring more than 40 units of insulin daily, 47 (87 per cent) required combined therapy.The primary objection to combined therapy is that it is a compromise, still requiring multiple