Steady state is reached within 2-3 days of once-daily administration of degludec, a basal insulin with an ultralong duration of action.

Background: Various factors influence the pharmacokinetic and pharmacodynamic properties of insulin analogs. The aim of the present study was to determine time to steady state of insulin degludec (IDeg), a basal insulin analog with an ultralong duration of action, after once-daily subcutaneous administration in subjects of varying age, diabetes type, and ethnicity.

Methods: Time to steady state was analyzed in 195 subjects across five Phase I randomized single-center double-blind studies: three in subjects with type 1 diabetes (T1DM), including one in elderly subjects, and two in subjects with type 2 diabetes (T2DM), including one with African American and Hispanic/Latino subpopulations. Subjects received once-daily IDeg (100 U/mL, s.c.) at doses of 0.4-0.8 U/kg for 6-12 days. Time to clinical steady state was measured from first dose until the serum IDeg trough concentration exceeded 90% of the final plateau level. The IDeg concentrations were log-transformed and analyzed using a mixed-effects model with time from first dose and dose level (where applicable) as fixed effects, and subject as a random effect.

Results: Steady state serum IDeg concentrations were reached after 2-3 days in all subjects. In trials with multiple dose levels, time to steady state was independent of dose level in T1DM (P = 0.51) and T2DM (P = 0.75).

Conclusions: Serum IDeg concentrations reached steady state within 2-3 days of once-daily subcutaneous administration in all subjects with T1DM or T2DM, including elderly and African American and Hispanic/Latino subjects. At steady state, serum IDeg concentrations were unchanged from day to day.