Insulin - "How and when" to use insulin in diabetes!

Online Physician By Online Physician, 25th Sep 2011 | Follow this author | RSS Feed
Posted in Wikinut>Health>Drugs & Medicines

Insulin is an anabolic hormone secreted by the β cells of the pancreas. Lack of insulin secretion or its action in the target tissue is the pathophysiology of diabetes mellitus and replacement of insulin as a drug is one of the commonest and standard treatments of diabetes. This article discusses how insulin is used as a drug and its benefits and adverse effects.

Insulin - the magic drug of diabetics!

Diabetes is a disease caused by the absolute (lack of production) or relative (increased resistance at the tissues of the body) to insulin, a hormone produced by the pancreas. This leads to abnormally high levels of blood glucose accompanied by excessive passage of urine, excessive thirst and loss of weight. As the high levels of bllod sugar can leads to many complications as described in another article by the author, it is important to control the level of blood sugar in the physiological range. For this, synthetic insulin is used very effectively. This article is aimed at describing how the doses of insulin is determined for each patient, how it should be injected, the evolving methods of injection and the common side effects of insulin therapy, being a continuum of the article What is "Insulin - an account on its action, its role in diabetes and its uses as a drug".

How is the insulin dose determined?

The dose of insulin required for individual patients depend on the type of diabetes, height, weight, blood glucose level, insulin resistance and comorbidities (diseases the patients are suffering apart from diabetes). In addition, the action of insulin differs depending on the mode of delivery.
· Subcutaneous: long action (4 hours ) , slow absorption to the circulation, depends on blood flow
· Intravenous: rapid absorption, action 4-5 min, value in diabetes ketoacidosis
· Intramuscular: long action (2 hours )

Timing of insulin delivery depends on the disease process and the response. The best method which is mostly physiological is called Basal-Bolus regimen where rapid acting or short acting insulin is given half an hour before meals and give intermediate or long-acting insulin is given in the evening at bedtime.

What is the correct technique of injecting insulin?

There are different methods of delivery such as jet injectors, infusion pumps, and bolus injections; here injecting insulin using a syringe or insulin pen is the commonest method. The healthcare professionals should be well aware of the injection technique in order to educate the patients and the care givers.
1. Area of skin in which about 1 inch of subcutaneous fat can be pinched between two fingers should be chosen
2. Syringe with a 0.5 inch, microfine (27G) needle is inserted perpendicular to the skin up to the hilt & injected
3. Syringe barrel should not be pulled back before injection
4. Cleaning the skin with an alcohol swab may not be necessary
5. Insulin absorbed fastest from the abdominal wall, slowest from leg & buttock, intermediate from arm
6. Absorption varies inversely with subcutaneous fat thickness so pre-meal regular should be injected to abdominal wall and intermediate acting to leg or buttock

What are the emerging methods of insulin delivery?

Another method of delivering insulin is Continuous Subcutaneous Insulin Infusion (CSII) delivered via insulin pump using rapid acting insulin analogs; the advantage of this is that it allows great life style flexibility but here patient must be strongly motivated and requires skilled professionals. It is indicated when conventional therapy less effective. Complications related to this are blocking of catheter, ketoacidosis, infection/inflammation at needle site and hypoglycaemia.

Pancreas / Islet cell transplantation is a latest method described and there is inhalational insulin which is also under experimental level. Inhalational insulin is an alternative to monomeric insulin which carries greater patient satisfaction and convenience. It causes a rapid rise in serum insulin concentration. However, the problem is here that the absorption is inefficient and therefore requires 10 fold higher doses of insulin compared to other standard routes of administration.

What are the side effects of insulin?

Adverse effects of insulin therapy are,
· Hypoglycemia (sudden reduction in the levels of blood glucose)
· Weight gain
· Lypodystrophy (abnormal distribution of fat in a disfiguring manner)
· Antibody formation
· Allergy
· Insulin odema

In spite of all the complications and the trouble of injecting everyday, insulin is the most physiological way of treating diabetes mellitus. The response to treatment is assessed by measuring glycosylated haemoglobin called HBA1C which is high in poorly controlled diabetes mellitus. Insulin becomes second only to the drug Metformin among all the treatment modalities in reducing HBA1C.

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author avatar Denise O
7th Feb 2012 (#)

I have only had to deal with insulin with my dog Max. He had diabetes. Great information. Thank you for sharing.:)

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