Antidiabetogenic Drugs, Insulin

Sources include pork or beef, combination of pork and beef and also human insulin (Recombinant DNA technique).

Actions:

• Insulin lower blood glucose level through increasing utilization of glucose by peripheral tissue and promoting synthesis and storage of glycogen
• The main actions of the hormone are exerted on metabolism of carbohydrate (CHO), fat and protein in liver, muscle & adipose tissue.

Effects of insulin

Carbohydrate metabolism

Liver:       it increases glycogen synthesis from glucose and glucose utilization while decreases gluconeogenesis and glycogenolysis.

Muscle: it increases glucose uptake, glucose utilization and glycogen synthesis. Adipose tissue: it increases glucose uptake and glycerol synthesis (esterifies fatty acid).

Fat metabolism

Liver: it increases lipogenesis

Adipose tissue: it increases synthesis of triglycerides and synthesis of fatty acid

Protein metabolism

Liver:       it increases protein catabolism

Muscle: it increases aminoacid uptake and protein synthesis

Other metabolic effect:

It increases uptake of K⁺ and Ca⁺⁺ into cells and synthesis of nucleic acids

There are some factors that increase insulin demand: like Infection, surgery, pregnancy and drugs (those that antagonize actions of insulin glucocorticoids, thyroid hormone, adrenaline).

Type of insulin preparation:

1. Short acting (rapid onset): Eg Regular Insuline
2. Intermediate acting Eg Lente insuline,NPH insuline
3. Long acting E.g Protamine Zn insuline

Types	Route	Onset (hrs)	Duration (hrs)
Regular insulin	IV, SC, IM	¼ – 1	5 – 7
Lente insulin	SC, IM	1 – 1½	18 – 24
Protamine Zn insulin	SC, IM	4 – 8	36

N.B. It is only regular insulin that can be given by intravenous route.

Therapeutic use -IDDM, NIDDM (not controlled by diet and oral hypoglycemic agents), diabetic ketoacidosis, Control of diabetes in pregnancy, during surgery and in infections.

They are also used in the treatment of hyper kalmia due to renal failure.

Adverse Reaction: can be categorized as

Local:     Atrophy or hypertrophy at site of injection, local hypersensitivity and secondary infections.

Systemic: Hypoglycemic coma and Immunologic reaction like hypersensitive and insulin resistance.