Insulin detemir

Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.

Levemir FlexPen (Novo Nordisk)
3 mL cartridges containing 100 U/mL
Approved indication: diabetes mellitus
Australian Medicines Handbook section 10.1.1

Analogues of insulin enable patients with diabetes to be treated with regimens that follow the pattern of normal insulin secretion.¹ Insulin detemir is a soluble analogue designed to provide the basal requirements for insulin.

The genetically engineered molecule has a fatty acid side chain which delays absorption and degradation. Insulin detemir is active for 3-14 hours after subcutaneous injection. Depending on the dose, the duration of action can extend to 24 hours, so some patients can manage with a single daily dose.

An open-label study compared insulin detemir with the intermediate acting NPH insulin. The 56 patients, with type 1 diabetes, used one insulin at night for six weeks then switched over to the other insulin. Larger doses of insulin detemir were required to maintain good glycaemic control and serum glucose concentrations were higher for the first few hours after a dose. During the last week of treatment, hypoglycaemia occurred in 60% of the patients injecting insulin detemir and 77% of those injecting NPH insulin.²

A larger study compared twice-daily doses of the two insulins. After 16 weeks, the 267 patients given insulin detemir had a lower fasting blood glucose than the 124 patients who had taken NPH insulin. The mean concentration of glycated haemoglobin (HbA_1c) decreased slightly more in patients given insulin detemir (mean difference between groups 0.18%).³

Studies lasting up to a year show that the effect of insulin detemir on HbA_1c is equivalent to the effect of NPH insulin.

As insulin detemir only gradually reduces blood glucose during the night, nocturnal hypoglycaemia is less likely than with NPH insulin. However, there are no significant differences in the frequency of major hypoglycaemia.²

To achieve good glycaemic control, patients taking insulin detemir for their basal requirements should also be prescribed a short-acting insulin. Although insulin detemir has been studied in type 2 diabetes it is not currently approved for this indication unless there is no longer a response to oral hypoglycaemic drugs.

The activity profile of insulin detemir may have some advantages over older insulins. It is unknown if this difference will actually improve the outcomes for patients.