Diabetes medications

The different classes of drugs used in type 2 diabetes include sulphonylureas, biguanides (Metformin), acarbose, glitazones, insulin, and other drugs, currently unfunded. Factors such as being overweight and/or having other medical conditions can influence the choice of medication(s). Most are taken as tablets. Insulin, which many people with type 2 diabetes find beneficial at some stage, is used by injecting just under the skin (not in a vein).

Does everyone need medication?

To begin with, not everyone with type 2 diabetes may need to use medications, especially if lifestyle measures are helping to control their blood glucose levels. Sometimes people feel as though they have 'failed' in their diabetes management if they need to go onto medication. However, type 2 diabetes is a process. Virtually everyone with Type 2 diabetes at some stage needs medication to help them manage their diabetes.

Healthy blood pressure important also

Recent research has proved that having healthy blood glucose and blood pressure levels greatly reduces the chance of you getting the complications of diabetes. Developing the complications of diabetes is a process. If you have the early signs of complications, achieving healthy blood glucose and blood pressure levels may slow down or even halt the progress of these.

Medication to lower blood glucose levels

Currently there are three main groups of tablets available in New Zealand that can help lower your blood glucose levels. These groups of tablets work in different ways.

Sulphonylurea tablets
These tablets work by making your pancreas produce more insulin. They will only work if your pancreas is able to make more insulin. For this reason some people find that these tablets work well for them earlier on in their diabetes, but there comes a time when they no longer work so well.

Sulphonylurea tablets sometimes don't work very well in people who are overweight. This is because being overweight can make your body resistant to the action of insulin.

The sulphonylurea tablets available are marketed under different names:

• gliclazide (Diamicron, Apo-Gliclazide) 
• glipizide (Minidiab)
• glibenclamide (Daonil).

These tablets do increase the chances of your blood glucose level going low. So it’s important not to skip your meals when you take sulphonylurea tablets. You also need to learn about low blood glucose levels, how to avoid them, how to recognise them and how to treat them.

Biguanides (Metformin)
There is only one biguanide tablet, called Metformin. This tablet works by making your body cells and muscles more sensitive to the action of insulin. It does not make your pancreas make more insulin. This means if you are only taking Metformin (and not insulin or sulphonylurea tablets) for your diabetes, you are not at risk of having low blood glucose levels.

Metformin tends to work best for people who are overweight. This is because people who are overweight tend to have muscles and cells that don't respond very well to the action of insulin.

Metformin should only ever be taken with food. If you take it on an empty stomach it can make you can feel nauseous. If you are starting on Metformin it is best for you to start on one tablet only per day, then build up to the dose you need gradually over the next few weeks. If you start on a large dose straight away, it can cause you to have diarrhoea and/or nausea. If you are on Metformin, and you get an illness that causes you to have vomiting or diarrhoea, you should stop taking your Metformin until you are well again.

Alpha-glucosidase inhibitors
At present there is only one drug from this class available in New Zealand called acarbose (or Glucobay). It works by slowing down and reducing the breakdown of complex carbohydrates (starches) into glucose in your stomach and gut. Like Metformin, it’s best to start on a low dose of acarbose and build up the dose slowly over the next few weeks, as it can cause a lot of wind. It is best to take acarbose at the start of your meal.

If you are taking acarbose only for your diabetes you are not at risk of getting low blood glucose levels. However, if you take insulin or sulphonylureas with acarbose you can get low blood glucose levels. If your blood glucose goes low and you are taking acarbose you should treat your low blood glucose with glucose tablets before using more complex carbohydrates (eg. starchy food).

Give the glucose tablets at least 5 - 10 minutes to be absorbed before taking more complex carbohydrate. This is because the acarbose slows down the breakdown of complex carbohydrates into glucose in your gut.

Other drug treatments
Other drug treatments, such as glitazones (eg, pioglitazone), may be useful in a minority of people with type 2 diabetes.

There are also other types of medication available but these are currently unfunded. These include DPP-4 (dipeptidyl peptidase 4) inhibitors and GLP (glucagon-like peptide) classes. If long term studies show favourable outcomes it is possible they will be used more in the future.

Insulin

Most people feel afraid if they need to go onto insulin. But the vast majority of people with type 2 diabetes are surprised at how well they manage on insulin. Once they are on insulin many people feel much better and have a lot more energy.

Insulin needles are now very short and extremely fine. The injection goes just under your skin (not into a vein). Nearly everyone finds that the injection is fairly painless. Most people find having an insulin injection much more comfortable than doing finger pricks.

Extra energy on insulin
Going onto insulin nearly always leads to your blood glucose levels coming down. This is because the extra insulin is helping your blood glucose to move into your muscles and cells where it can then be burnt up to give you energy. This explains why most people find they have more energy once on insulin.

When you have type 2 diabetes and you go onto insulin, you are generally taking this insulin to supplement your own body’s insulin production. People with type 1 diabetes, however, are dependent on insulin to survive. This is because they either have no insulin at all of their own, or very little.

'Insulin requiring' vs 'insulin dependent'
People with type 1 diabetes are 'insulin dependent' (if their insulin injections are stopped it is life-threatening). However, people with type 2 diabetes who are on insulin are 'insulin requiring'. They require insulin to manage their blood glucose levels. If the insulin is stopped they may become unwell, but this is generally not life-threatening (because they still have some of their own insulin).

What is insulin and where does it come from?

Insulin is a hormone which occurs naturally in the human body. The insulin you get from the chemist is manufactured in the laboratory. It is made by cell organisms that have had the human gene for making insulin spliced into them. These cells then busily make insulin. This human insulin is a very safe product to take and there have been no instances of insulin becoming contaminated with anything harmful.

Taking insulin for type 2 diabetes

Common ways of taking insulin for type 2 diabetes include:

• a once a day dose of insulin (often at bedtime)
• a twice a day dose of insulin (single type of insulin, or two types mixed together).

Either of these ways of taking insulin may be combined with diabetes tablets (biguanides or sulphonylureas). Some people with type 2 diabetes may take insulin more often, eg. three or four times daily, but this is less common.

Medication to lower blood pressure

Having your blood pressure in a healthy range is as important as having healthy blood glucose levels and will improve your chances of avoiding the complications of diabetes. Some studies show you have a 40 - 50% lower chance of developing complications if you have your blood pressure in a healthy range. The recommended blood pressure for those with diabetes is less than (or possibly equal to) 130/80. Younger people with diabetes may be given a lower target - your doctor will advise.

Sometimes it is possible to lower your blood pressure into a healthy range by a combination of losing weight, getting regular exercise, lowering the amount of salt in your diet, and stopping smoking. However, if your blood pressure is still high after you have put these strategies in place, you may need medication. There are different types of blood pressure medication, and factors such as other medical conditions you may have, will influence which are best for you. 

Don't forget lifestyle measures

Whatever medication you are on to lower your blood pressure and/or blood glucose, never forget that by decreasing your body weight (if you are overweight), keeping active and eating in a healthy way, you may be able to reduce the amount of medication you need to keep your blood glucose and blood pressure within healthy levels.

Original material provided by Diabetes New Zealand, 2008. Edited by everybody, August 2011.