Insulin glargine is a long-acting, recombinant human insulin analogue used for the control of hyperglycemia in diabetes mellitus. It is a clear, colourless solution for subcutaneous injection. The 3.64 IU/ml concentration is equivalent to 100 IU/ml (U-100) in terms of biological activity, but presented in a 1:1.5 ratio (3.64 IU/ml = 100 IU/1.5ml) for specific pen devices. It is designed to provide a basal level of insulin with a relatively constant concentration/time profile over 24 hours with a single daily injection.
Adult: Individualized. Typically initiated at 0.2 IU/kg or 10 IU once daily, adjusted based on fasting blood glucose (FBG) targets. Dose is titrated by 2-4 IU every 3-4 days until FBG target is achieved.
Note: For subcutaneous injection only. Administer once daily at the same time each day, preferably at bedtime. Rotate injection sites (abdomen, thigh, upper arm) to prevent lipodystrophy. Use a new needle for each injection. Do not shake. Inspect visually; should be clear and colourless. Do not administer intravenously or intramuscularly.
Insulin glargine is a human insulin analogue where asparagine at position A21 is replaced by glycine and two arginines are added to the C-terminus of the B-chain. This modification shifts the isoelectric point towards a neutral pH, making it less soluble at physiological pH. After subcutaneous injection, it forms microprecipitates from which small amounts of insulin glargine are slowly released, resulting in a prolonged, relatively peakless profile.
Pregnancy: Pregnancy Category C. Use only if clearly needed. Insulin requirements may decrease in first trimester and increase significantly in second/third trimesters. Close monitoring of blood glucose is mandatory. Human insulin is preferred, but insulin glargine can be used under specialist supervision.
Driving: Caution advised. Ability to concentrate and react may be impaired as a result of hypoglycemia or hyperglycemia. Patients should check blood glucose before driving and have a fast-acting carbohydrate source available.
| Oral Hypoglycemics (Sulfonylureas, Meglitinides) | Additive hypoglycemic effect | Major |
| Beta-blockers (e.g., Propranolol) | Mask tachycardia warning signs of hypoglycemia; may potentiate or impair glucose recovery | Moderate |
| Thiazides, Loop Diuretics | May cause hyperglycemia, increasing insulin requirement | Moderate |
| Corticosteroids (e.g., Prednisolone) | Cause hyperglycemia, increasing insulin requirement | Major |
| ACE Inhibitors, MAOIs, Pentamidine | May increase hypoglycemic effect | Moderate |
| Alcohol | Potentiates hypoglycemic effect; can cause delayed hypoglycemia | Major |
Same composition (Insulin Glargine (3.64IU/ml)), different brands: