Insulins
Insulin lispro, aspart
lispro: reversal of sequence of lysine and proline on B chain.
Eliminates hydrophobic interactions and weakens the hydrogen bonds that
contribute to the stability of insulin dimers. The zinc hexamers
are therefore less stable and dissociate more rapidly into monomers.
Onset and clearance are therefore more rapid.
Often used with a long acting insulin (e.g., isophane insulin, insulin zinc, &c.)
Reduced frequency of hypoglycaemic episodes in patients with type 1 DM.
Soluble insulin
= short acting insulin
The only insulin appropriate for treating diabetic ketoacidosis or hyperosmolar
non-ketotic hyperglycaemia. Also used in hyperkalaemia.
Subcutaneously, onset 30–60 min, peak 2–4 h, duration 8 h.
Intravenously, t½=5 min.
Hyperkalaemia
50 ml 50% glucose + 15 units soluble insulin over 30 min.
Intermediate & long-acting insulins
Onset 1–2 h, peak 4–12 h, duration 16–36 h.