Comparing dosing of basal insulin analogues detemir and glargine: is it really unit-per-unit and dose-per-dose?

Objective: To review the available evidence regarding dosing conversion between glargine and detemir in an effort to assist clinicians in performing dosing conversion.

Data sources: A MEDLINE literature search was performed using the search terms glargine and detemir for articles published through August 2013.

Study selection and data extraction: All English-language clinical trials were reviewed for inclusion of dosing and/or pharmacokinetic data.

Data synthesis: A total of 7 large (n ≥ 258) randomized controlled trials (RCTs) comparing glargine and detemir in patients with type 1 and 2 diabetes had dosing equivalency data available. In these 7 RCTs, on average, a 38% higher detemir dose was required (range = 8.0%-77.2%) to achieve glucose control comparable to that achieved with glargine. A 24-hour isoglycemic clamp study conducted in 11 patients with type 1 diabetes demonstrated that the duration of action of detemir is dose dependent, with increasing doses of detemir resulting in increased duration of action of detemir. Pharmacokinetic studies conducted in patients with type 2 diabetes are conflicting, although the majority of evidence suggests that glargine provides a longer duration of glycemic control as compared with detemir.

Conclusions: When performing conversion between glargine and detemir, prescribers should be aware that higher doses of detemir as compared with glargine may be necessary to achieve the same glycemic control. Additionally, twice-daily injections of detemir should be considered in clinical situations in which glucose control appears to decline after 12 hours, especially with doses ≤0.4 units/kg/d in patients with type 1 diabetes.