Insulin lispro: a review of its pharmacological properties and therapeutic use in the management of diabetes mellitus.

Insulin lispro, a recombinant insulin analogue, is identical to human insulin except for the transposition of proline and lysine at positions 28 and 29 in the C-terminus of the B chain. The resultant reduced capacity for self-association in solution translates into more rapid absorption of insulin lispro than human regular insulin from subcutaneous sites. Maximum insulin concentrations are higher and are reached earlier with insulin lispro than with human regular insulin, and insulin concentrations return to baseline values more quickly with insulin lispro; consequently, insulin lispro has a more rapid onset and a shorter duration of glucose-lowering activity. These pharmacological properties provided the rationale for comparative clinical trials of subcutaneous insulin lispro (administered within 15 minutes before meals, preferably immediately before meals) and subcutaneous human regular insulin (administered 20 to 45 minutes before meals) in patients with type 1 diabetes (insulin-dependent diabetes mellitus) or type 2 diabetes (non-insulin-dependent diabetes mellitus) requiring premeal insulin therapy plus basal insulin therapy. Available clinical trials are well designed and results suggest that 1- and 2-hour postprandial blood glucose levels with insulin lispro are similar to or lower than those with human regular insulin; 1- and 2-hourpostprandial glucose excursions are similar to or less pronounced than those with human regular insulin. Glycated haemoglobin A values were generally similar with both agents. Continuous subcutaneous insulin infusion was associated with greater improvements in postprandial blood glucose levels and glycated haemoglobin A1 values with insulin lispro than with human regular insulin. Confirmatory data are required. The incidence of hypoglycaemia with insulin lispro was similar to or lower than that with human regular insulin. In particular insulin lispro appears to be associated with a lower incidence of night-time and severe hypoglycaemic episodes. Evidence also suggests that patients perceive their quality of life to be improved with insulin lispro compared with human regular insulin, and that satisfaction with treatment is greater with the insulin analogue. Thus, in patients with type 1 or 2 diabetes requiring premeal insulin therapy, insulin lispro appears to provide greater postprandial glycaemic control than human regular insulin without increasing the risk of hypoglycaemia. Furthermore, the reduced injection-meal interval with this agent offers greater convenience for the patient than regular human insulin. If longer term clinical experience supports these promising results it is likely that insulin lispro will offer important advantages over human regular insulin.