1. Clinical Overview
Insulin Lispro (200IU) is a concentrated, rapid-acting human insulin analogue used for the management of hyperglycemia in diabetes mellitus. It is a monomeric insulin created by reversing the amino acids proline and lysine at positions 28 and 29 of the B-chain of human insulin. This modification reduces self-association, leading to faster absorption, an earlier and sharper peak, and a shorter duration of action compared to regular human insulin. The 200IU/mL concentration (U-200) is twice as concentrated as standard insulin (U-100), allowing for the administration of a smaller injection volume for the same dose, which can improve comfort and potentially accuracy for patients requiring high doses.
| Onset | Duration | Bioavailability |
|---|---|---|
| Approximately 15 minutes | 3 to 5 hours | 55-77% (Subcutaneous) |
2. Mechanism of Action
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 cascade activates PI3K and MAPK pathways, leading to the translocation of GLUT4 glucose transporters to the cell membrane, facilitating cellular glucose uptake. It also inhibits hepatic glycogenolysis and gluconeogenesis while promoting glycogenesis, lipogenesis, and protein synthesis.
3. Indications & Uses
- Management of Type 1 Diabetes Mellitus
- Management of Type 2 Diabetes Mellitus in patients requiring insulin therapy
4. Dosage & Administration
Adult Dosage: Highly individualized. Typically administered 0-15 minutes before a meal. Dose is based on blood glucose levels, carbohydrate intake, and anticipated physical activity. In U-200 strength, the volume injected is half that of U-100 for the same number of units.
Administration: For SUBCUTANEOUS use only. Administer in abdominal wall, thigh, buttocks, or upper arm. Rotate injection sites. Use ONLY U-200 specific syringes or pre-filled pens. Do not mix with other insulins in the same syringe unless specifically indicated (e.g., with specific protamine-based insulin lispro mixtures). Inspect visually before use; should be clear and colorless. Do not use if cloudy, viscous, or discolored.
5. Side Effects
Common side effects may include:
- Hypoglycemia (sweating, tremor, palpitations, hunger, confusion)
- Injection site reactions (redness, itching, pain, lipodystrophy)
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Beta-blockers (e.g., Propranolol, Metoprolol) | Mask tachycardia warning signs of hypoglycemia; may potentiate or weaken glucose-lowering effect. | Major |
| Corticosteroids (e.g., Prednisolone, Dexamethasone) | Antagonize insulin effect, causing hyperglycemia and increased insulin requirements. | Major |
| Thiazolidinediones (e.g., Pioglitazone) | Can cause fluid retention and worsen/trigger heart failure; monitor for edema and weight gain. | Moderate |
| Alcohol | Potentiates glucose-lowering effect, increasing risk of hypoglycemia, which can be delayed for up to 24 hours. | Major |
| ACE Inhibitors (e.g., Ramipril) | May increase insulin sensitivity, potentially increasing hypoglycemia risk. | Moderate |
| SGLT2 Inhibitors (e.g., Dapagliflozin) | Increased risk of Euglycemic Diabetic Ketoacidosis (euDKA). Requires careful monitoring and possible insulin dose adjustment. | Major |
7. Patient Counselling
- DO check blood sugar levels regularly, especially before meals and driving.
- DO inject 0-15 minutes BEFORE a meal.
- DO rotate injection sites to prevent lipodystrophy.
- DO use only U-200 specific syringes/pens.
- DO carry a fast-acting sugar source (glucose tablets) at all times.
- DON'T skip meals after injection.
- DON'T share pens or syringes.
- DON'T inject into moles, scars, or areas of redness/lumps.
- DON'T use if the solution is cloudy or discolored.
8. Toxicology & Storage
Overdose: Profound hypoglycemia: sweating, tremor, tachycardia, hunger, anxiety, confusion, slurred speech, seizures, loss of consciousness, coma, and death if untreated.
Storage: Unopened (Refrigerated): Store at 2°C to 8°C. Do not freeze. Keep away from freezer compartment and direct sunlight. In-use (Opened vial/pen): Can be stored at room temperature (below 30°C) or refrigerated. Must be used within 28 days. Do not store in-use insulin in direct sunlight or in a hot car. Always check expiry date. For Indian conditions with frequent power cuts, consider a cool storage box. Do not use if frozen or exposed to excessive heat.