OBJECTIVES: The objective was to determine whether the use of insulin glargine (IG, Lantus) could result in cost savings in comparison with insulin detemir (ID, Levemir) in T2D patients in the UK. METHODS: Clinical data for the analysis was taken from a 1 year multi-national study (Rosenstock 2008) in 582 insulin-naïve patients treated with IG or ID as add-on therapy to oral glucose lowering drugs. IG was administered once daily in line with it's licence and ID once (44% of patients) or twice daily (55%) according to treatment response. Mean daily insulin doses were 40U for IG and 71U for ID. Baseline characteristics were comparable on study entry. After 1 year glycaemic control, weight gain, adverse events and risk of hypoglycaemia were similar for both groups so a cost minimisation analysis was undertaken. Costs were calculated from a UK NHS perspective using MIMS November 2010 prices. Insulin cost was based on IG SoloStar and ID FlexPen prefilled disposable injection devices, which are of similar cost. It was assumed that a new needle, lancet and blood glucose test strip were used for each injection with a 2U priming dose of insulin before each injection. RESULTS: The annual cost per patient for needles was £43 for IG and £66 for ID. The cost of lancets and test strips was £122 for IG and £190 for ID. The annual cost of insulin was £426 for IG and £758 for ID. The total annual cost per patient of administering IG was £591 compared with £1014 for ID. Sensitivity analyses for weight gain, IG device and insulin dose confirmed the robustness of the base case results. CONCLUSIONS: IG may represent a more cost effective option for T2D patients in the UK requiring basal insulin analogue therapy with potential annual cost savings of 42% (£423/patient) compared with ID.