Human insulin. A review of its biological activity, pharmacokinetics and therapeutic use.

Human insulin, whether produced by recombinant DNA techniques (biosynthetic, insulin crb) or enzymatic modification of porcine insulin (semisynthetic, insulin emp) is equivalent in biological activity to porcine insulin following intravenous administration. Slight differences between human and porcine insulin in hypoglycaemic activity after subcutaneous injection appear to be related to differences in absorption, and are unlikely to be of major clinical importance. Similarly, reported minor differences in counterregulator hormone response to human insulin compared with porcine insulin need further study, but they are unlikely to have important clinical implications. In clinical use the therapeutic efficacy of human insulin is similar to that of porcine insulin. The lower antigenicity with human insulin relative to purified porcine insulin is of potential therapeutic value, and it is logical to use human insulin in newly diagnosed diabetics, in patients treated intermittently with insulin, in cases of immunological insulin resistance, and in patients with allergy and local reaction against animal insulin. Thus, human insulin seems to have no disadvantages compared with purified porcine insulin and may have some advantages. While there appears to be no compelling reason to change patients whose diabetes is presently well controlled with purified porcine insulin to human insulin, the availability of human insulin at a price equal to or less than that of animal origin makes such a change logical. In the meantime, human insulin should be considered the insulin of 'first choice' for newly diagnosed diabetics requiring insulin therapy and in carbohydrate intolerance and diabetes occurring during pregnancy.