Insulin glargine
Lantus · Abasaglar · Toujeo · Semglee
The basal insulin that covers the basal insulin requirement between meals and overnight, with a largely flat profile over 24 hours and therefore a lower risk of nocturnal hypoglycaemia than NPH insulin. It is titrated against fasting glucose and nothing else — the morning fasting value drives the evening dose. Available in two strengths, 100 units/ml and 300 units/ml, and the two are not the same medicine even though both are dosed in units.
Toujeo 300 units/ml and Lantus or Abasaglar 100 units/ml must never be confused or switched on a one-to-one basis. When switching from 300 units/ml to 100 units/ml the dose should be reduced by approximately 20 %, otherwise severe hypoglycaemia results. Glargine must never be given intravenously and never as a correction dose for hyperglycaemia — onset is too slow and duration too long.
Dosing in adults
| Indication | Regimen | Comment |
|---|---|---|
| Basal insulin in type 1 diabetes | Approximately half the total daily dose (0,3–0,5 units/kg/day total) as one injection at the same time each day | always combined with mealtime insulin |
| Insulin initiation in type 2 diabetes | 0,1–0,2 units/kg or 10 units at night, added to metformin and other oral treatment | the simplest and least expensive entry into insulin treatment |
| Titration | Increase by 2 units every 3 days until fasting glucose is in the target range, usually 4–7 mmol/l | reduce the dose at nocturnal or morning hypoglycaemia |
| Switch 100 units/ml → 300 units/ml (Toujeo) | Same number of units, but expect to need a 10–18 % dose increase for the same glucose control | frequent glucose monitoring the first weeks |
| Switch 300 units/ml → 100 units/ml | Reduce the dose by approximately 20 % at the switch | otherwise a marked hypoglycaemia risk |
Insulin requirements fall with declining renal function, most clearly below eGFR 30 ml/min, because insulin is partly degraded renally. No fixed percentage is specified — reduce the basal dose stepwise and monitor fasting glucose more frequently. During dialysis, requirements change across the dialysis day.
Requirements may decrease in severe hepatic failure due to reduced gluconeogenesis. No fixed dose adjustment; individual titration against fasting glucose.
Approved from 2 years of age. Same principles and same share of the daily dose as in adults; Toujeo 300 units/ml is used from 6 years of age. Follow the paediatric unit's routines.
Do not use glargine to correct acute hyperglycaemia or to treat ketoacidosis — it is a basal insulin without controllability, and an excessive dose cannot be retrieved and acts for a full day. The opposite error is equally common: completely stopping the basal insulin in a type 1 diabetic who is fasting before surgery, which triggers ketoacidosis despite a normal blood glucose.
Pharmacokinetics
- ONSET
- 1–2 hours
- PROFILE
- Largely without pronounced peak
- DURATION (100 UNITS/ML)
- up to 24 hours
- DURATION (300 UNITS/ML)
- over 24 hours, up to 36 hours
- STEADY STATE
- after 2–4 days
- CONVERSION
- To active metabolites M1 and M2 in subcutaneous tissue
- DEGRADATION
- Liver, kidney, and muscle
- STRENGTHS
- 100 units/ml and 300 units/ml