As much as 7% of the entire NHS budget on medicines is being spent on diabetes drugs, researchers have said.
The spiralling costs are not fully explained by the big rise in the number of people with type 2 diabetes, researchers from Cardiff University said.
They concluded that the NHS needs to get the budget under control, as the rates of the condition are expected to rise further.
The best interests of the patients must be sought, GPs said.
Figures show that in 2008 some £700m was spent by the NHS on drugs to control blood sugar.
The number of prescriptions for glucose-lowering drugs rose by a half between 2000 and 2008 researchers calculated.
Even taking into account the price of inflation, costs rose by 104%, they said.
Over the study period figures for England specifically showed an increase from £290m to £591m, researchers wrote in the Clinical Pharmacist journal.
Marked increase in use of the most expensive therapies was pointed out by the researchers.
The increased costs have been contributed to by newer drugs, such as rosiglitazone, as well as increasing use of insulin – the hormone that controls blood sugar levels in the body.
Before drug treatment is started lifestyle changes should be made as a first-step in controlling type 2 diabetes, the National Institute for Health and Clinical Excellence recommends.
Copyright Press Association 2010