There are a number of tablet treatments available for the treatment of Type 2 diabetes. Please note that tablet treatments are not used in the treatment of Type 1 diabetes, which is always treated with insulin.
The most important tablet treatment is metformin. This has been used for a long time in the treatment of diabetes which means that we know a lot about it and are very clear on its side effects. It has been shown to have a beneficial effect on preventing complications of diabetes and is now offered as first treatment to everybody with type 2 diabetes from the time of diagnosis. It is sometimes used in the treatment of type 1 diabetes together with insulin.
Metformin makes you more sensitive to the glucose lowering effect of your own insulin and therefore takes pressure off your pancreas as it doesn’t need to work so hard. It stops sugar from being released from your liver and slows the digestion of sugars from food. It does not make you put on weight, and you may even lose a little. On its own, it will never lower your blood glucose below normal, so there is no risk of the blood glucose dropping dangerously low.
The common side effects are due to its effects on the gut. Most people who start taking it get a little abdominal discomfort, but this generally passes. For that reason, we usually start with one tablet a day, increasing gradually as tolerated. Unfortunately, a small minority of people simply can’t tolerate it due to sickness or diarrhoea or even constipation. There is a slow release form of the tablet which is much easier to tolerate, but about one person in 20 can’t take it and we need to find alternatives.
The smallest useful dose is 500mg twice daily, but can be up to 3g (6 of the 500mg tablets approximately 4 of the 850mg tablets or 3 of the 1g tablets).
This is another group of treatments which we have been using for many years.
They cause the release of insulin from the pancreas and lower the blood glucose by that method.
They have remarkably few side effects. The most important is that they lower blood glucose very effectively and override the body’s own protection methods. This means that they can lower the blood glucose to figures below normal and cause hypoglycaemia (low glucose). This tends to happen soon after starting if it is going to happen, and when we use them, we always start with a low dose and work up. Once established on these, hypoglycaemia is rare, but can still happen if food intake is restricted or an unusual amount of exercise is undertaken.
Because these agents work by increasing insulin levels, they can stimulate weight gain, but this is generally not an issue if they are used sparingly.
These are relative newcomers to the list of tablets for the treatment of type 2 diabetes. They work by increasing the levels of the stomach hormone GLP-1. This hormone is produced when you eat. It decreases the appetite, slows the stomach action and gets insulin from the pancreas.
These tablets have little in the way of side effects, and we have not come across any problems in our use of any of them. They leave the sugar sensing mechanisms in the body intact, so will never lower the blood glucose too far. They do not promote weight gain.
The only downside of these tablets is that they are very mild indeed. They may lower your blood glucose by about 1-2mmol/l and will drop the HbA1c value by about 5mmol/mol. However, they are very useful when used with other tablets, or if a mild agent is required.
These are also newcomers in the treatment of type 2 diabetes. They work by allowing sugar to escape through the kidneys into the urine. Normally this sugar loss is claimed back by the system, so allowing this to escape lowers the blood glucose level and also results in calorie loss and perhaps weight loss.
The significant side effects are the need to pass urine more frequently, and perhaps urinary infections, including thrush. In our experience, these side effects are uncommon, but people taking these agents need to be warned of the possibility.
The ‘flozins’ are not effective if kidney function is poor. Your routine tests include a kidney measurement called the eGFR which is calculated from the blood tests. If this is less than 40, these agents will not be effective. If you are taking water tablets, the urine overflow can be dramatic, so we tend not to use these tablets in people taking furosemide or bumetanide.
This agent is a stand alone, the only one of its class still in use. It is little used these days because of side effects. It causes fluid retention and weight gain. There has been a recent scare that it may increase the risk of bladder cancer, although if true, the risk is very small. It also causes thinning of the bones of the hands and feet. In some people it is strikingly effective in lowering blood glucose, so it can be considered as a treatment option after consideration of all the treatment alternatives.