Insulin Lispro

• Type 1 diabetes mellitus
• Type 2 diabetes mellitus requiring insulin
• Gestational diabetes (with healthcare provider guidance)
• Diabetic ketoacidosis (as part of treatment protocol)
• Blood sugar control during hospitalization

Insulin lispro is a rapid-acting insulin analog used to control blood sugar levels in people with diabetes mellitus. It is designed to mimic the body's natural insulin response to meals, providing quick glucose-lowering action when food is consumed.

How Insulin Lispro Works

Insulin lispro is created by reversing the amino acid sequence at positions 28 and 29 of the insulin B-chain (lysine-proline instead of proline-lysine). This modification reduces the tendency of insulin molecules to form hexamers, allowing faster absorption from the injection site. The result is more rapid onset and shorter duration of action compared to regular human insulin.

Pharmacokinetics

After subcutaneous injection, insulin lispro begins working within 15-30 minutes, peaks at 30-90 minutes, and has a duration of 3-5 hours. This profile closely matches the natural insulin response to eating. When administered via insulin pump, onset may be even faster.

Available Formulations

• Humalog: Original brand insulin lispro
• Admelog: Biosimilar insulin lispro
• Lyumjev: Ultra-rapid insulin lispro with faster onset
• Humalog Mix: Premixed with intermediate-acting insulin

Concentrations include U-100 (100 units/mL) and U-200 (200 units/mL) for patients requiring higher doses.

Administration

Insulin lispro should be injected subcutaneously within 15 minutes before or immediately after meals. Injection sites include the abdomen, thigh, upper arm, or buttocks. Rotation of injection sites helps prevent lipodystrophy. For insulin pump users, insulin lispro can be used for continuous subcutaneous infusion.

Dosing Considerations

Dosing is highly individualized based on blood glucose monitoring, meals, physical activity, and metabolic needs. Many patients use carbohydrate counting to determine mealtime doses. Total daily insulin requirements typically range from 0.4-1.0 units/kg, with about 50% as basal and 50% as bolus (mealtime) insulin.

Important Safety Information

Hypoglycemia is the most common and potentially serious side effect. Symptoms include shakiness, sweating, confusion, rapid heartbeat, and hunger. Severe hypoglycemia can cause seizures, loss of consciousness, or death. Patients should always carry fast-acting glucose and wear medical identification.

Storage Requirements

Unopened vials and pens should be refrigerated at 36-46°F (2-8°C). Once in use, insulin lispro can be kept at room temperature (below 86°F/30°C) for up to 28 days. Avoid freezing and protect from direct heat and light.

Drug Interactions

Many medications affect blood glucose levels. Drugs that may increase hypoglycemia risk include other antidiabetic agents, ACE inhibitors, and certain antibiotics. Medications that may raise blood glucose include corticosteroids, thiazide diuretics, and some antipsychotics. Beta-blockers may mask hypoglycemia symptoms.

Learn more at MedlinePlus