Type 2 diabetes can often initially be managed through lifestyle changes alone, most people with Type 2 diabetes will need to progress to medication to help manage their blood glucose levels. In the past, when people with Type 2 diabetes were no longer able to manage the condition through lifestyle alone, insulin was then used to help control blood glucose levels. Since 1930s other treatments to help manage Type 2 diabetes have been developed.
These new non-insulin treatments have different modes of action. They are able to
- Reduce carbohydrate digestion
- Increase insulin secretion
- Enhance insulin sensitivity
- Increase the amount of glucose passed out in urine
The first of these new treatments to be developed were the sulphonylureas in 1937. They act on the beta cells, which are the insulin producing cells in the pancreas. They work by increasing insulin secretion and so decreasing blood glucose levels. Because they increase the amount of insulin, they can cause hypoglycaemia where blood glucose levels fall to low. As with all medications, sulphonylureas have other side effects that people may or may not experience. A healthcare professional will be best able to advise on specific side effects someone may be having.
E.g. Gliclazide, Glimepiride
Biguandes are used to reduce the production of glucose in the liver and promote the uptake of glucose from the blood stream into muscle cells. These two processes simultaneously lower blood glucose levels in the blood and over time help to decrease insulin resistance. Therefore insulin produced by the pancreas is able to work more effectively. A useful property of Biguanides such as Metformin is that they are able to lower blood glucose levels without the risk of causing hypoglycaemia. Unfortunately metformin can have some uncomfortable side effects in some individuals such as abdominal pains and diarrhoea, this can be reduced by taking the medication with food and there is also a slow release version.
Thiazolidinedione / Glitazones
They reduce the production of glucose by the liver and stimulate glucose uptake in muscle.
Thiazolidinediones, also known as glitazones, are a medication for Type 2 diabetes which help to improve insulin sensitivity and have been found to help decrease triglyceride levels. However, there is some research to suggest that this drug class has been linked to increased risk of heart attacks and bladder cancer. Therefore it is important that healthcare professionals consider the potential risks and benefits carefully before prescribing a glitazone.
Alpha- glucosidase inhibitors
This class of drug were discovered in 1990, they slow down absorption and breakdown of carbohydrates during digestion. This helps prevent sharp spikes in glucose levels in the blood which the body is less able to cope with compared will slow, low level release of glucose. Therefore the body is better able to manage and process the glucose in the blood. As with other medications, this class of drugs can have some side effects such as increased flatulence or wind.
The glinides are a class of drug which have a similar response as sulphonylureas but act for a shorter time. Meglitinides are prescribed to be taken by people with Type 2 diabetes within half an hour before eating. As the drugs act for a shorter period than sulphonylureas, the side effect of hypoglycemia has a smaller likelihood.
Glucagon-like-peptide -1 agonists/ Incretin mimetics
This type of medication works by increasing the amount of incretin hormones. Incretins help the body produce more insulin only when needed and reduce the amount of glucose being produced by the liver when it’s not needed. This class of drug was discovered in 2005, from an unlikely the source, the saliva of the Glia monster, which has in it a hormone known as exendin-4 which is released in response to food in the mouth. The properties of exendin-4 are similar to glucaon-like-protein-1 in humans. Other effects of the drug include a decrease in appetite and slower emptying of the stomach contents. Doses tend to be gradually increased to reduce gastrointestinal side effects.
DPP-4 inhibitors work by blocking the action of DPP-4, an enzyme which destroys the hormone incretin (see above). These hormones are released throughout the day and levels are increased at meal times. Side effects can include gastro-intestinal symptoms such as stomach pain, nausea and diarrhoea.
SGL-2 inhibitors block the re-uptake of glucose in the kidneys, which is the excreted out in urine. Less glucose reabsorbed by the kidneys means there is less glucose in the blood so better diabetes management. As there is more glucose in the urine a side effect of this treatment can be risk of genital and urinary tract infections.