Insulin Lispro is a rapid-acting human insulin analogue used for the management of hyperglycemia in diabetes mellitus. It is created by reversing the amino acids proline and lysine at positions 28 and 29 of the human insulin B-chain. This modification reduces the propensity for self-association into dimers and hexamers, allowing for faster absorption from subcutaneous tissue, a more rapid onset of action, and a shorter duration of effect compared to regular human insulin. It is typically administered immediately before or after meals to control postprandial glucose excursions.
Adult: Highly individualized. Typically 0.5 to 1.0 unit/kg/day, divided into multiple doses. The pre-meal dose is based on carbohydrate intake, pre-meal blood glucose, and anticipated physical activity. Usually administered 0-15 minutes before or immediately after a meal.
Note: For subcutaneous use only. Inject into abdominal wall, thigh, buttocks, or upper arm. Rotate injection sites within the same region. Use a new needle for each injection. Do not mix with other insulins in the same syringe unless specifically indicated (e.g., with specific NPH formulations). If using a pre-filled pen, prime the needle with 2 units before each injection. Do not share pens or needles.
Insulin Lispro binds to the alpha-subunit of the transmembrane insulin receptor, a tyrosine kinase receptor, on target cells (primarily liver, muscle, and adipose tissue). This binding triggers autophosphorylation of the receptor and subsequent phosphorylation of intracellular signaling proteins (IRS-1, Shc). This activates two main pathways: the PI3-kinase/Akt pathway (mediating metabolic effects like glucose uptake and glycogen synthesis) and the MAP-kinase pathway (mediating growth-promoting effects).
Pregnancy: Pregnancy Category B. Insulin is the drug of choice for glycemic control in pregnancy (both pre-existing and gestational diabetes). Requirements may decrease in first trimester and increase significantly in second/third trimesters. Close monitoring (fasting and postprandial glucose, HbA1c) is mandatory. Insulin Lispro is considered safe but should be used under strict supervision of an endocrinologist/obstetrician.
Driving: Patients must check blood glucose before driving and at regular intervals during long journeys. Must have fast-acting carbohydrates (glucose tablets) available. Driving should be avoided during periods of poor glycemic control or if hypoglycemia awareness is impaired.
| Corticosteroids (e.g., Prednisolone) | Antagonize insulin effect, increasing blood glucose. Requires dose increase. | Major |
| Beta-blockers (e.g., Propranolol) | May mask tachycardia of hypoglycemia and impair counter-regulatory response. Can also potentiate hypoglycemic effect. | Moderate |
| Thiazolidinediones (e.g., Pioglitazone) | Can cause fluid retention, exacerbating or precipitating heart failure. Monitor weight and edema. | Major |
| Alcohol | Potentiates hypoglycemic effect and impairs gluconeogenesis. Risk of delayed hypoglycemia. | Major |
| MAO Inhibitors, ACE Inhibitors | May potentiate hypoglycemic effect. | Moderate |
| Oral Hypoglycemics (Sulfonylureas, Meglitinides) | Additive hypoglycemic effect. Risk of severe hypoglycemia. | Major |
| Thyroid Hormones, Diuretics (Thiazides, Loop) | May increase blood glucose, requiring insulin dose adjustment. | Moderate |