Insulin Lispro Pharmacology and Clinical Use

Introduction to Insulin Lispro

The American Academy of Family Physicians notes that insulin lispro has an onset of 5 minutes, peaks at 1-2 hours, and lasts only 3-4 hours, making it fundamentally different from long-acting basal insulins like glargine 1

Insulin lispro is absorbed significantly faster than regular human insulin, with a half-life of approximately 1 hour, which is shorter than regular insulin's 1.5 hours 1

The American Diabetes Association guidelines clarify that rapid-acting insulin analogs like lispro control postprandial blood glucose more effectively than regular insulin, and should be used as prandial insulin to control postprandial glucose spikes 1
The American Diabetes Association recommends that lispro can be given after meals in young children with unpredictable eating patterns, allowing for flexible dosing 2

The American Diabetes Association and European Association for the Study of Diabetes recommend combining lispro with intermediate- or long-acting basal insulin, such as NPH, insulin glargine, or insulin detemir, to achieve 24-hour glucose control 3

The American Academy of Family Physicians notes that the rapid onset of lispro means hypoglycemia can develop quickly, giving patients less time to recognize symptoms, and patients must be thoroughly educated on recognition and treatment of hypoglycemia 1
The American Diabetes Association recommends that patients on lispro should be educated on glucose monitoring requirements, such as monitoring at least 4 times daily for type 1 diabetes 2
The Diabetes Care journal notes that patients on lispro should be educated on the need to eat within a certain time frame after injection, and on the recognition and treatment of hypoglycemia 3

The American Diabetes Association recommends adding prandial insulin when fasting glucose is controlled but HbA1c remains elevated after 3-6 months of basal insulin titration, or when significant postprandial glucose excursions exceed 180 mg/dL despite adequate basal insulin dosing 4, 5
Postprandial glucose spikes greater than 180 mg/dL, despite target fasting levels, indicate the need for prandial insulin therapy 4, 5

The American College of Endocrinology suggests starting with one meal, typically the meal causing the largest postprandial glucose excursion, often dinner, when adding Humalog 4, 5

Humalog provides rapid onset, peaking at 1-2 hours, and lasts 3-4 hours, making it effective for controlling postprandial glucose excursions 6
The American Academy of Family Physicians recommends discontinuing sulfonylureas and meglitinides once prandial insulin is started to avoid hypoglycemia 4, 5

Daily self-monitoring of fasting and postprandial glucose is essential during titration, with a target postprandial glucose of less than 180 mg/dL 4, 5

Rapid-acting insulin like Humalog can cause rapid-onset hypoglycemia, and patients must be educated on recognizing and treating hypoglycemia 6
The American Geriatrics Society suggests that for elderly patients, less intensive regimens may be more appropriate, with higher HbA1c targets 4, 5