DIABETES- TYPE OF INSULIN

Types of Insulin

Different types of insulin preparations are distinguished by the speed at which the injected insulin is absorbed from the layer under the skin into the blood (onset of action) and by the time it takes for all the injected insulin to be absorbed (duration of action).

It is important to note that the duration and absorption times described below are only approximate. Absorption of insulin always depends on individual factors.

Insulin analogues

1.Rapid-acting insulin analogue
Onset: 10-20 minutes
Maximum effect: 1-3 hours
Duration: 3-5 hours
Indication: treatment of diabetes mellitus

2.Long-acting insulin analogue
Onset: 1 hour
Duration: 24 hours
Indication: treatment of diabetes mellitus

3.Biphasic insulin analogue
Onset: 10-20 minutes
Maximum effect: 1-4 hours
Duration: up to 24 hours

Human insulins

1.Short-acting insulin
(soluble human insulin)

This insulin comes in a clear solution, and is intended to be given at meals. An injection should be followed by a meal or snack containing carbohydrates within 30 minutes.
Onset: within 30 minutes
Maximum effect: 1-3 hours
Duration: 8 hours

2.Intermediate-acting insulin
(isophane human insulin, NPH)

An insulin formulation that contains a substance, which delays the absorption of insulin. The combination of insulin and a delaying substance usually results in the formation of crystals that give the liquid a cloudy look. The insulin crystals must be homogenised (mixed) evenly before each injection. Intermediate-acting insulin takes approximately 1 1/2 hours before it begins to have an effect. The largest effect occurs between 4 and 12 hours after the injection, and after approximately 24 hours, the whole dose has been absorbed
Onset: within 1.5 hours

Maximum effect: 4-12 hours
Duration: 24 hours

3.Premixed insulin

(biphasic human insulin consisting of e.g. 30% soluble and 70% isophane insulin)

Insulin containing a combination of a short-acting and an intermediate-acting insulin in standard proportions. These products eliminate the difficulty some individuals have while mixing insulin. The products come in several different premixed combinations containing 10-50% short-acting insulin and 90-50% intermediate-acting insulin, with the ratio of 30% short acting and 70% intermediate acting being the most used.

 Onset: within 30 minutes
Maximum effect: 2-8 hours
Duration: 24 hour

INJECTION SITE SELECTION

The most common injection site is the abdomen (or stomach). The back of the upper arms, the upper buttocks or hips, and the outer side of the thighs are also used. These sites are the best to inject into for two reasons:

• They have a layer of fat just below the skin to absorb the insulin, but not many nerves - which means that injecting there will be more comfortable than injecting in other parts of your body.
• They make it easier to inject into the subcutaneous tissue, where insulin injection is recommended.

   Depending on your body type, you'll find that certain injection sites work better than others.

• Some people, for example, prefer injecting in the abdomen because the insulin absorbs well there.
• But injecting in the abdomen isn't right for everyone, especially young children or people who are so thin and/or heavily muscled that they can't pinch up a half-inch of fat.

Consult with your doctor in choosing the injection sites that are best for you. Your doctor will consider both insulin absorption and site rotation.

DO NOT INJECT:

• near moles
• near scars
• areas that looked inflamed, infected, or have a rash
• within 2 inches of the naval (all the way around)
• the same spot (see "Rotating Your Injection Site," below)

WAYS OF INJECTING INSULIN

1. Hands.  Wash hands with warm, soapy water using plenty of friction.
2. Clean the site.  Make sure the injection site is clean and sterilized with soap and water or an alcohol pad.  The area should be dry before injecting because you need to make sure all the insulin gets under the skin.  If skin is wet you won't be able to tell.
3. Numbing the area.  You can numb the area with ice, a bag of frozen vegetables (never put cold objects directly on the skin, wrap them in a hand towel or wash cloth).  This is usually not necessary but sometimes helps children feel better about a forthcoming shot.
   Numbing creams that contain lidocaine are expensive and have some side effects and are not recommended for multiple daily injections.
   Cold insulin right from the refrigerator can causes stinging when injected.  It is fine to let your pen, or syringe warm up for 5 minutes, or, even the bottle of insulin for 5-10 minutes.
4. Pinch up a fold of skin surrounding the site you've selected. Hold it firmly with one hand you can inject insulin into muscle, but it is more painful and it is better to inject into fat when possible.
5. Inserting the needle.  Faster is better, inserting slowly will cause more pain.  Try inserting the needle almost like you would toss a dart.6.
6. Needle angle.  For adults or those with good fatty tissue, insert at a 90° angle. Thin adults and children may need to inject at a 45° angle.Try to get the needle all the way into fatty tissue below the skin, but not so deep that it hits the muscle below.
7. Injecting the insulin. Push the syringe plunger all the way in with a slow steady motion or firmly press the insulin pen injection button. The injection should take a couple of seconds, unless you take a very small dose. Let go of the skin.  

Remove the needle by pulling straight out. Twisting or shifting the needle's position will cause pain.  You may gently press on the injection site with your finger for a couple seconds. Do not rub or massage the skin where the insulin is injected; it can affect how fast the insulin is absorbed and acts within the body