Insulin pharmacology and regimens

At a glance

• Insulin acts through a receptor tyrosine kinase. The PI3K-Akt branch drives GLUT4 translocation, glycogen synthesis and suppression of lipolysis and gluconeogenesis; the MAPK branch mediates growth.
• Analogues alter absorption from the subcutis by changing hexamer stability, isoelectric point or albumin binding. The receptor action is the same.
• About half of portal insulin is cleared by the liver on first pass, and the kidney clears about a third of systemic insulin. Insulin needs fall with kidney failure.