Insulin

Pronounced: IN-suh-lin
Brand names: Apidra, Humalog, Humulin, Iletin, Novolin

Why is Insulin prescribed?

Insulin is prescribed for diabetes mellitus when diet modifications and oral medications fail to correct the condition. Insulin is a hormone produced by the pancreas, a large gland that lies near the stomach. This hormone is necessary for the body's correct use of food, especially sugar. Insulin apparently works by helping sugar penetrate the cell wall, where it is then utilized by the cell. In people with diabetes, the body either does not make enough insulin, or the insulin that is produced cannot be used properly.

There are actually two forms of diabetes: type 1 (insulin-dependent) and type 2 (non-insulin-dependent). Type 1 usually requires insulin injection for life, while type 2 diabetes can usually be treated by dietary changes and/or oral antidiabetic medications such as Diabinese, Glucotrol, and Glucophage. Occasionally, type 2 diabetics must take insulin injections on a temporary basis, especially during stressful periods or times of illness.

The various available types of insulin differ in several ways: in the source (animal, human, or genetically engineered), in the time requirements for the insulin to take effect, and in the length of time the insulin remains working.

Regular insulin is manufactured from beef and pork pancreas, begins working within 30 to 60 minutes, and lasts for 6 to 8 hours. Variations of insulin have been developed to satisfy the needs of individual patients. For example, zinc suspension insulin is an intermediate-acting insulin that starts working within 1 to 1-1/2 hours and lasts approximately 24 hours. Insulin combined with zinc and protamine is a longer-acting insulin that takes effect within 4 to 6 hours and lasts up to 36 hours. The time and course of action may vary considerably in different individuals or at different times in the same individual. Genetically engineered insulin works faster and for a shorter length of time than regular human insulin and should be used along with a longer-acting insulin. It is available only by prescription.