A third of patients prescribed a common diabetes drug do not take their medication because of the side effects, researchers have warned.
Metformin, which costs as little as 1p per pill, is the most commonly prescribed drug for type two diabetes.
Records do not reveal how many of the 3.4million people in the UK with type two diabetes are given the drug, but every year nearly 19million prescriptions are issued in England alone.
Metformin help diabetics control their condition by reducing the levels of sugar produced by the liver.
Metformin, which costs as little as 1p per pill, is the most commonly prescribed drug for type two diabetes (stock photo)
For many people it is an essential – yet University of Surrey researchers found 30 per cent of prescribed doses are never taken.
The researchers, whose findings are published in the journal Diabetes, Obesity and Metabolism, believe the side effects are to blame.
Other diabetes drugs called gliclazide are only shunned by 23 per cent of patients, 20 per cent do not take prescribed pioglitazone.
Metformin commonly causes gastrointestinal symptoms such as diarrhoea and flatulence.
Researcher Dr Andy McGovern, whose team tracked 1.6million people with type two diabetes, said: ‘The importance of diabetes patients taking their prescribed medication cannot be underestimated.
For many people it is an essential – yet University of Surrey researchers found 30 per cent of prescribed doses are never taken (stock photo)
‘A failure to do so can lead to complications in their condition including eye disease and kidney damage.
‘Medication which is not taken does no good for the patient but still costs the NHS money so this is an important issue.
‘We have known for a long time that a lot of medication prescribed for chronic diseases never actually get taken.
‘What this latest research suggests is that patients find some of these medication classes much easier to take than others.’
He added: ‘I urge anyone who is struggling to take their medication as prescribed, whether this is because of side effects or because the schedule is too complicated, to discuss this openly with their doctor or nurse.
‘Fortunately for type two diabetes we have lots of treatment options and switching to a different medication class which is easier to take could provide an easy way to improve adherence.
‘I would also encourage doctors and nurses to actively ask their patients about medication adherence.’