Insulin glargine

Insulin glargine is an extended-action biosynthetic human insulin. It precipitates in the neutral environment of subcutaneous tissue and is thus gradually absorbed into the bloodstream. The addition of small amounts of zinc to the formulation further delays absorption. In small euglycaemic clamp studies, the onset of action of insulin glargine was shown to be later, the duration of action longer and the time-action profile flatter than that of Neutral Protamine Hagedorn (NPH) insulin in patients with type 1 diabetes mellitus and healthy volunteers. Four large clinical trials of up to 28 weeks' duration have shown that a single bedtime dose of insulin glargine, in combination with preprandial short-acting insulin, is as effective or more effective than once or twice daily NPH plus short-acting insulin in improving glycaemic control in patients with type 1 diabetes mellitus. In 3 large comparative trials, insulin glargine decreased glycosylated haemoglobin and/or fasting blood glucose levels to a similar extent to that seen with NPH insulin in patients with insulin-dependent or non-insulin-dependent type 2 diabetes mellitus, either as monotherapy or in combination with oral hypoglycaemic agents. Insulin glargine appears to be well tolerated. A lower incidence of hypoglycaemia, especially at night, was reported in most trials with insulin glargine when compared with NPH insulin.