DIFFERENT TYPES OF INSULIN AND THEIR USES

Today we are going to discuss about the different types of insulin available and what are there functions and uses.

Before discussing about different types of insulin we must know why is insulin important for a diabetic person.

So let’s start:-

Insulin for diabetes

Insulin is a hormone our body makes to keep our blood glucose levels within the normal range. It is made by beta cells in the pancreas. Insulin's main job is to move glucose from our bloodstream into the body's cells to make energy. If you don’t have enough insulin, the glucose builds up in your bloodstream instead of providing energy for your body. 

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.

Starting on insulin

People with type 1 diabetes must inject insulin every day, often up to four or five times per day. They may use a pump to deliver insulin which means they insert a new cannula (very fine plastic tube) under the skin every two to three days. Sometimes, people with type 2 diabetes also need to begin using insulin when diet, physical activity and tablets no longer effectively control their blood glucose levels.

Having to start injecting insulin can be frightening. However, injecting insulin is much easier than most people imagine. There are different devices that can be used to make insulin delivery easy. Pen needles are very fine and so are cannulas. Often people needing insulin feel much better once they start having insulin.

If you need to start using insulin, your doctor or diabetes nurse educator can help with education and support. They will teach you about:

·        the type and action of your insulin

·        how, where and when to inject insulin

·        how to rotate injection sites

·        where to get your insulin and how to store it safely

·        how to manage low blood glucose

·        how to keep a record of your blood glucose levels and insulin doses

·        who will help you to adjust insulin doses.

Insulin doses usually don’t stay the same as your starting dose. Your doctor will help you to adjust your insulin. An important part of insulin adjustment is regular blood glucose monitoring and recording. 

It may take some time to safely reach the right dose of insulin for you. And because your insulin needs won’t necessarily remain constant throughout your life, you will need to see your diabetes health care team regularly for review.

When you start using insulin it is important to have a review to understand how carbohydrates and insulin work together.

If you have type 1 diabetes, learning how to count carbohydrates and matching your insulin to the food you eat is the ideal way to manage it. Depending on what you eat, your mealtime insulin doses may therefore vary from meal to meal and day to day.

Types of insulin

Rapid- and short-acting insulin helps reduce blood glucose levels at mealtimes and intermediate or long-acting insulin helps with managing the body’s general needs. Both help manage blood glucose levels.

Insulin is grouped according to how long it works in the body. The five different types of insulin range from rapid- to long-acting. Some types of insulin look clear, while others are cloudy. Check with your pharmacist whether the insulin you are taking should be clear or cloudy.

Before injecting a cloudy insulin, the pen or vial needs to be gently rolled between your hands to make sure the insulin is evenly mixed (until it looks milky). Don't use clear insulin if it appears cloudy.

Often, people need both rapid- and longer-acting insulin. Everyone is different and needs different combinations.

The five 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 three hours after injection and can last up to five 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 after you inject.

The three rapid-acting insulin types currently available 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 two to five hours after injection and lasts for six to eight 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 are:

·               Protaphane (a human isophane insulin).

·        Humulin NPH (a human isophane insulin)

Long-acting insulin

The long-acting insulins currently available 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 three 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 to18 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 are:

·        rapid-acting and intermediate-acting insulin  

o   Ryzodeg 70:30 (70% long acting Degludec, 30% rapid Aspart)

o   NovoMix 30 (30% rapid, 70% intermediate Protaphane)

o   Humalog Mix 25 (25% rapid, 75% intermediate Humulin NPH)

o   Humalog Mix 50 (50% rapid, 50% intermediate Humulin NPH)

·        short-acting and intermediate-acting insulin  

o   Mixtard 30/70 (30% short, 70% intermediate Protaphane)

o   Mixtard 50/50 (50% short, 50% intermediate Protaphane)

o   Humulin 30/70 (30% short, 70% intermediate Humulin NPH).

I have discussed about different types of insulin and in next article we will be discussing about various devices to inject the insulin. So make sure you follow us for more updates.

In case you have any doubt or query feel free to comment in comment section below.