These are tablets used to help lower blood sugar in people who have type 2 diabetes. They work as an adjunct or aid to diet and should only be used in the setting of a healthy diet.
People with type 2 diabetes, who are poorly controlled on diet alone. Type 1 diabetes should always be treated with insulin injections.
There are several oral hypoglycaemic drugs available. Each group has different properties and glucose lowering potential.
Each of these groups work in individual ways.
The sulphonylureas work by stimulating release of insulin from the pancreatic beta cells. There are different preparations within this group with largely similar efficacy. The main differences between them relate to how potent they are and the dosing schedule. They tend to be more effective in people with newly diagnosed diabetes. Refer to the separate page on sulphonylureas for more information.
Metformin reduces the amount of glucose produced by the liver and increases uptake of glucose by the cells of the body. It does not stimulate the pancreas.
The Glitazones or Thiazolidenediones to give them their full name, make your body more sensitive to insulin. In other words the amounts of insulin available in your body is allowed to work more effectively.
The Prandial Glucose releasers also stimulate insulin release. They differ from the sulphonylureas in having a rapid action and short duration of activity. They require to be taken at meal time and should be omitted if a meal is missed.
Acarbose works by blocking an enzyme in the bowel. This delays the absorption of starch and sugar in the diet. The impact on blood glucose levels is small and flatulence can be a problem!
Yes many of these tablets work well in combination and it is not unusual to be on three different oral hypoglycaemic drugs. The natural history of type 2 diabetes is of a gradual deterioration of pancreatic function resulting in an increase of medication. Most people with type 2 diabetes would eventually require insulin injections.
Dr. Nishan Wijenaike MD FRCP
West Suffolk Hospitals Diabetes Service
First Published Online October 2002
Updated November 2007