Name: Isophane insulin suspension (NPH insulin)
Class: Insulin (Intermediate-Acting Suspension)
Mechanism: Interacts w/ insulin receptors on cell membranes ® phosph/dephosph of enzymes ® glucose transport into cells (esp. fat & muscle), glycogen synth., ¯ FFA, triglyceride storage, K+ & Mg2+ uptake, protein synth. Regulation of cell proliferation & differentiation. May activate cAMP (significance unknown).
Absorption: Injection (usu. SC).
Dist.:
Metabolism.: Rapidly Metabolism. by liver, kidneys, and muscle.
Excretion, t½: 5-6 min.
Toxicity/S.E.s: Most freq. = hypoglycemia ® ANS hyperactivity, impaired CNS fxn (confusion, bizarre behavior, coma). Skin rxns—transient urticaria, subcut. fibrosis, localized atrophy of subcut. tissue. Allergic rxn. Insulin resistance—refractory receptors or anti-insulin antibodies (may require 200-1000 units/d).
Utility: Treat diabetes mellitus. Basal control of blood glucose.
Special Features: Equal concentrations of insulin and protamine. Intermediate duration (24 hr).