Insulins and Insulin Analogs
Insulin is a hormone produced by the pancreas that lowers blood glucose by facilitating glucose uptake into cells, especially in muscle and adipose tissue.
Pharmacodynamics
- Increases glucose uptake via GLUT4 transporters in muscle/adipose tissue.
- Promotes:
- Glycogenesis (glucose → glycogen in liver and muscles)
- Protein synthesis
- Lipogenesis
- Inhibits:
- Gluconeogenesis (new glucose production)
- Glycogenolysis (breakdown of glycogen)
- Lipolysis and ketogenesis
Pharmacokinetics
- Half-life:
- Endogenous insulin: few minutes
- Long-acting analogs: several hours
Therapeutic Uses
- Type 1 Diabetes Mellitus (lifelong insulin dependence)
- Type 2 Diabetes Mellitus (when oral drugs/lifestyle fail)
- Gestational diabetes
- Diabetic ketoacidosis (DKA)
- Hyperkalemia (insulin shifts K⁺ into cells, usually given with glucose)
- Perioperative glycemic control
Pregnancy & Milk
- Insulin is the preferred treatment during pregnancy (Type 1, Type 2, or GDM).
- Does not cross placenta → safe for fetus.
- Excreted in low amounts in breast milk, but generally safe during lactation.
Recap Questions
- What is the main difference between insulin lispro and insulin glargine?
- Why is insulin the first-line treatment in pregnancy?
- Which insulin has the longest duration of action?
- Name a drug that can increase the risk of insulin -induced hypoglycemia.
- What are the signs of insulin -induced lipodystrophy?