Insulin Lispro (25%) + Insulin Lispro Protamine (75%) is a biphasic premixed insulin analogue formulation. It consists of 25% rapid-acting insulin lispro and 75% intermediate-acting insulin lispro protamine suspension. This combination provides both a rapid onset to control postprandial glucose excursions and a prolonged duration to provide basal insulin coverage. It is a mainstay therapy for patients with type 1 and type 2 diabetes mellitus requiring a simplified insulin regimen, reducing the number of daily injections.
Adult: Highly individualized. Typically started at 0.2-0.4 units/kg/day or 10 units/day, divided into 2-3 injections (usually before breakfast and dinner). Dose is titrated based on pre-meal and bedtime blood glucose monitoring.
Note: For subcutaneous use only. Inject into abdominal wall, thigh, buttocks, or upper arm. Rotate sites within a region. Administer immediately (within 15 minutes) before a meal. Before use, gently roll the vial/pen between palms 10 times until the suspension appears uniformly cloudy/ milky. Do not shake vigorously. Do not use if clumping, frosting, or precipitation is seen.
Insulin lispro is an insulin analogue where the natural amino acid sequence at positions B28 (proline) and B29 (lysine) is reversed. This modification reduces the propensity for self-association into hexamers, allowing for faster absorption from subcutaneous tissue. The protamine-bound lispro component forms a crystalline suspension that delays absorption, providing an intermediate duration of action. The combination mimics both prandial and basal insulin secretion.
Pregnancy: Pregnancy Category B. Insulin is the drug of choice for diabetes in pregnancy. Requirements may decrease in first trimester and increase significantly in second/third trimesters. Close monitoring of blood glucose is mandatory. Insulin lispro protamine mixture can be used but may require more frequent injections or a basal-bolus regimen for optimal control.
Driving: Patients must be warned about the risk of hypoglycemia impairing concentration and motor skills. Blood glucose should be checked before driving and at regular intervals during long journeys. Fast-acting carbohydrates must be available.
| Oral Hypoglycemic Agents (Sulfonylureas, Meglitinides) | Additive glucose-lowering effect, increased hypoglycemia risk | Major |
| Corticosteroids (e.g., Prednisone) | Antagonize insulin effect, increase insulin requirements | Major |
| Beta-blockers (non-selective like Propranolol) | Mask tachycardia warning signs of hypoglycemia, may potentiate or impair recovery from hypoglycemia | Major |
| Thiazide Diuretics | May cause hyperglycemia, increasing insulin requirements | Moderate |
| ACE Inhibitors (e.g., Ramipril) | May enhance hypoglycemic effect | Moderate |
| Alcohol | Potentiates hypoglycemic effect and impairs gluconeogenesis; risk of delayed hypoglycemia | Major |
| Octreotide, Lanreotide | Alters glucose metabolism, may increase or decrease insulin need | Moderate |
| MAO Inhibitors, Anabolic Steroids | Potentiate hypoglycemic effect | Moderate |
Same composition (Insulin Lispro (25%) + Insulin Lispro Protamine (75%)), different brands: