Diabetes drug could increase risk of heart failure, warn experts

Published on Thursday 3 December 2009 21:29

A COMMONLY prescribed class of drugs used by people with diabetes could increase the risk of heart failure and death, experts warn today.

Diabetics taking tablets known as sulphonylureas as their only therapy for Type 2 diabetes had a 24 per cent to 61 per cent increased risk of dying and up to a 30 per cent increased risk of heart failure compared with people taking the drug metformin.

The researchers said their findings back up current UK guidance that patients should be given metformin as a first treatment for Type 2 diabetes. Only those who cannot tolerate metformin should be given sulphonylureas as their only treatment, they said.

Around 550,000 diabetics in the UK take sulphonylureas drugs, although few of these are thought to be taking them on their own without metformin.

Approximately 200,000 people in Scotland have the condition – 4.1 per cent of the population – while tens of thousands are unaware they have it.

Lead researcher Dr Ioanna Tzoulaki, from Imperial College London, said: "When we looked at metformin and sulphonylureas together we didn't see an increased risk of heart failure or death.

"This might be because the sulphonylureas dose used when it is in combination with metformin is not as high as on its own, so you might not see the effect.

"It is also possible that metformin could be protective.

"Other studies looking at the drugs together have been inconclusive.

"It's very important that people do not stop taking their medication as a result of this study."

The researchers found no increased risk for people taking a combination of metformin and sulphonylureas medicines, although they said more research was needed.

The latest study, published online in the British Medical Journal, was based on the GP records of 91,521 people in the UK with an average age of 65 who were followed for an average of seven years. Over that time, there were 3,588 heart attacks, 6,900 cases of congestive heart failure and 18,548 deaths.

Dr Iain Frame, director of research at Diabetes UK, said the results should be treated with caution and said people with Type 2 diabetes should not stop taking sulphonylureas.

"If you are concerned about taking this medication you should contact your GP or diabetes healthcare team."

However, Margaret Watt, chair of Scotland Patients Association, said GPs should take a more pro-active approach to the research.

"GPs should be alerting their patients who are taking sulphonylureas," she said.