Clinical pharmacokinetics and pharmacodynamics of insulin glulisine.

Insulin glulisine injection [3(B)-Lys, 29(B)-Glu-human insulin] is the newest human insulin analogue product for the control of mealtime blood sugar. As with insulin aspart and insulin lispro products, the insulin glulisine product displays faster absorption and onset of action, with a shorter duration of action than that of regular human insulin. The modifications of the amino acid sequence at positions 3 and 29 in the B chain of human insulin simultaneously provide stability to the molecular structure and render the insulin glulisine molecule less likely to self-associate, compared with human insulin, while still allowing the formation of dimers at pharmaceutical concentrations. Unlike other insulin analogue products, this allows for a viable drug product in the absence of hexamer-promoting zinc and, thus, provides immediate availability of insulin glulisine molecules at the injection site for absorption. Pharmacokinetic studies with insulin glulisine have shown an absorption profile with a peak insulin concentration approximately twice that of regular human insulin, which is reached in approximately half the time. Dose proportionality in early, maximum and total exposure is observed for insulin glulisine over the therapeutic relevant dose range up to 0.4 U/kg. The pharmacodynamic profile of insulin glulisine reflects the absorption kinetics by demonstrating a greater rate of glucose utilization, which is completed earlier and at equipotency on a molar base compared with regular human insulin. Dose-proportionality in glucose utilization has been established for insulin glulisine in patients with type 1 diabetes mellitus in the dose range of 0.075-0.15 U/kg, and a less than dose-proportional increase above 0.15 U/kg, indicating saturation of insulin action in general. The rapid absorption and action of insulin glulisine show similar low intrasubject variability compared with insulin lispro and regular human insulin when given repeatedly, and have been confirmed in healthy subjects of different body mass indices (BMIs) and ethnic groups, as well as adults and children with type 1 and type 2 diabetes. Furthermore, the early insulin exposure and action of insulin glulisine were slightly -- but consistently -- greater than those of insulin lispro in healthy volunteers across a wide range of BMIs.Meal studies in patients with type 1 diabetes show that insulin glulisine provides better postprandial blood glucose control than regular human insulin when administered immediately pre-meal, and equivalent control when given after the meal. In a study in patients with type 2 diabetes, the overall postprandial blood glucose excursions were lower with insulin glulisine than with insulin lispro. Therefore, by virtue of its primary structure, insulin glulisine demonstrates both low self-association in solution and stability for a viable insulin product in the absence of zinc, thereby maintaining immediate availability for absorption after subcutaneous injection. This confers the most rapid onset of glucose-lowering activity and adds to the flexibility in postprandial blood glucose control.