With type 1 diabetes, the body does not make any insulin and therefore insulin has to be injected regularly every day to stay alive. With type 2 diabetes, the body does not make enough insulin, or the insulin that is made does not work well. Insulin injections are sometimes needed to manage blood glucose levels.
The 5 types of insulin are:
rapid-acting insulin
short-acting insulin
intermediate-acting insulin
mixed insulin
long-acting insulin.
Rapid-acting insulin
Rapid-acting insulin starts working somewhere between 2.5 to 20 minutes after injection. Its action is at its greatest between one and 3 hours after injection and can last up to 5 hours. This type of insulin acts more quickly after a meal, similar to the body's natural insulin, reducing the risk of a low blood glucose (blood glucose below 4 mmol/L). When you use this type of insulin, you must eat immediately or soon after you inject.
The 3 rapid-acting insulin types currently available in Australia are:
Fiasp and NovoRapid® (insulin aspart)
Humalog® (insulin lispro)
Apidra® (insulin glulisine).
Fiasp – released in Australia June 2019 – is a new, rapid acting insulin with faster onset of action. It is designed to improve blood glucose levels after a meal.
Short-acting insulin
Short-acting insulin takes longer to start working than the rapid-acting insulins.
Short-acting insulin begins to lower blood glucose levels within 30 minutes, so you need to have your injection 30 minutes before eating. It has its maximum effect 2 to 5 hours after injection and lasts for 6 to 8 hours.
Short-acting insulins currently available in Australia are:
Actrapid®
Humulin® R.
Intermediate-acting insulin
Intermediate-acting and long-acting insulins are often termed background or basal insulins.
The intermediate-acting insulins are cloudy in nature and need to be mixed well.
These insulins begin to work about 60 to 90 minutes after injection, peak between 4 to 12 hours and last for between 16 to 24 hours.
Intermediate-acting insulins currently available in Australia are:
Humulin® NPH (a human isophane insulin)
Protaphane® (a human isophane insulin).
Long-acting insulin
The long-acting insulins currently available in Australia are:
Lantus® (glargine insulin) – slow, steady release of insulin with no apparent peak action. One injection can last up to 24 hours. It is usually injected once a day but can be taken twice daily.
Toujeo (glargine insulin) – this insulin has a strength of 300 units per ml so is 3 times the concentration of other insulin in Australia. It is given once a day and lasts for at least 24 hours. It should not be confused with regular Lantus which has a strength of 100 units per ml. Toujeo is given for safety by a disposable pen only. Toujeo gives a slower, steadier glucose profile especially during the night.
Levemir® (detemir insulin) – slow, steady release of insulin with no apparent peak action and can last up to 18 hours. It is usually injected twice daily.
Although these insulins are long-acting, they are clear and do not need mixing before injecting.
Mixed insulin
Mixed insulin contains a pre-mixed combination of either very rapid-acting or short-acting insulin, together with intermediate-acting insulin.
The mixed insulins currently available in Australia are:
rapid-acting and intermediate-acting insulin
NovoMix® 30 (30% rapid, 70% intermediate Protaphane)
Humalog® Mix 25 (25% rapid, 75% intermediate Humulin NPH)
Humalog® Mix 50 (50% rapid, 50% intermediate Humulin NPH)
rapid-acting and long-acting inslulin
Ryzodeg 70:30 (70% long acting Degludec, 30% rapid Aspart)
short-acting and intermediate-acting insulin
Mixtard® 30/70 (30% short, 70% intermediate Protaphane)
Mixtard® 50/50 (50% short, 50% intermediate Protaphane)
Humulin® 30/70 (30% short, 70% intermediate Humulin NPH).
Note
In Australia, the strength of the above insulins is 100 units per ml. Some countries have different strengths.
The exception to this is the once-daily long-acting insulin Toujeo which was released in 2015 and has a strength of 300 units per ml. Do not change between Lantus and Toujeo without consulting a health professional.
Insulin injection devices
Different insulin delivery devices are available. The main choices are syringes, insulin pens and insulin pumps.
Insulin syringes
Syringes are manufactured in 30-unit (0.3 ml), 50-unit (0.5 ml) and 100-unit (1.0 ml) measures. The size of the syringe needed will depend on the insulin dose. For example, it is easier to measure a 10 unit dose in a 30 unit syringe and 55 units in a 100 unit syringe.
The needles on the syringes are available in lengths ranging from 6 to 8 mm. Your doctor or diabetes nurse educator will help you decide which syringe and needle size is right for you.
Insulin syringes are single-use only, and are free for people in Australia registered with the National Diabetes Service Scheme (NDSS). Most Australian adults no longer use syringes to inject insulin. They now use insulin pens for greater convenience.
Insulin pens
Insulin companies have designed insulin pens (disposable or reusable) to be used with their own brand of insulin.
Disposable insulin pens already have the insulin cartridge in the pen. They are discarded when they are empty, when they have been out of the fridge for one month, or when the use-by date is reached.
Reusable insulin pens require insertion of a 3 ml insulin catridge. The insulin strength per ml is 100 units. When finished, a new cartridge or penfill is inserted. Reusable insulin pens are designed by the insulin companies to fit their particular brand of insulin cartridge/penfill.
Pen cartridges also need to be discarded one month after commencing if insulin still remains in the cartridge.
Your doctor or diabetes nurse educator will advise you about the right type of pen for your needs.
Pen needles are disposable needles that screw on to an insulin pen device to allow insulin to be injected. They are available in different lengths, ranging from 4 to 12.7 mm. However research recommends that size 4 to 5 mm pen needles are used. The thickness of the needle (gauge) also varies – the higher the gauge, the finer the needle. It is important that a new pen needle is used with each injection. Your diabetes nurse educator can advise you on the appropriate needle length and show you correct injection technique.
Insulin pumps
An insulin pump is a small programmable device that holds a reservoir of insulin and is worn outside the body. The insulin pump is programmed to deliver insulin into the fatty tissue of the body (usually the abdomen) through thin plastic tubing known as an infusion set or giving set. Only rapid-acting insulin is used in the pump.
The infusion set has a fine needle or flexible cannula that is inserted just below the skin. This is changed every 2 to 3 days.
The pump is pre-programmed by the user and their health professional to automatically deliver small continual amounts of insulin to keep blood glucose levels stable between meals. Individuals can instruct the pump to deliver a burst of insulin each time food is eaten, similar to the way the pancreas does in people without diabetes.
The insulin pump isn't suitable for everyone. If you're considering using one, you must discuss it first with your diabetes healthcare team.
The cost of an insulin pump is generally covered by private health insurance for people with type 1 diabetes (a waiting period applies). Disposable extras required for use (such as cannulas, lines and reservoirs) are subsidised by the National Diabetes Service Scheme (NDSS).
Insulin injection sites
Insulin is injected through the skin into the fatty tissue known as the subcutaneous layer. It shouldn't go into muscle or directly into the blood, as this changes how quickly the insulin is absorbed and works.
Absorption of insulin varies depending on where in the body it is injected. The abdomen absorbs insulin the fastest and is used by most people. The upper arms, buttocks and thighs have a slower absorption rate and can also be used.
Factors that speed insulin absorption
Variation in insulin absorption can cause changes in blood glucose levels. Insulin absorption is increased by:
injecting into an exercised area such as the thighs or arms
high temperatures due to a hot shower, bath, hot water bottle, spa or sauna
massaging the area around the injection site
injecting into muscle – this causes the insulin to be absorbed more quickly and could cause blood glucose levels to drop too low.
Factors that delay insulin absorption
Insulin absorption can be delayed by:
over-use of the same injection site, which causes the area under the skin to become lumpy or scarred (known as lipohypertrophy)
insulin that is cold (for example, if insulin is injected immediately after taking it from the fridge)
No comments:
Post a Comment