Intramuscular injection of insulin lispro or soluble human insulin: pharmacokinetics and glucodynamics in Type 2 diabetes.

AIM: The aim of the study was to compare the pharmacokinetics and glucodynamics of insulin lispro and soluble human insulin following intramuscular (i.m.) injection in patients with Type 2 diabetes with secondary failure of sulphonylureas. METHODS: Single 15-U i.m. doses of insulin lispro or soluble human insulin were administered to 16 patients in a two-way, randomized, crossover design. Glucodynamic and pharmacokinetic parameters were determined over 6 h after insulin injection using clamp techniques. RESULTS: Insulin C(max) was significantly higher (971 +/- 217 vs. 659 +/- 141 pmol/l, P < 0.001) and T(max) was significantly shorter (46.9 +/- 27 vs. 94.7 +/- 50.1 min, P = 0.002) with insulin lispro. Glucose infusion rate (GIR) curves showed clear separation 20 min after injection and were significantly greater for insulin lispro during the 40-60, 60-80 and 80-100-minute time intervals. Total glucose infused was only approximately 5% larger with insulin lispro during the 6-h follow-up, due to lower insulinaemia at later time points. The glucose R(max) and TR(max) were not statistically different between insulin treatments. CONCLUSION: This study shows that i.m. injection of insulin lispro is followed by its more rapid absorption, which results in stronger metabolic effect in the first 2 h when compared with soluble human insulin under the same test conditions. Diabet. Med. 18, 562-566 (2001)