A study by Canadian researches has revealed that patients taking the type-2 diabetes drug Avandia may be at an increased risk of heart failure or death compared with those taking another kind of diabetes drug. Scientists with the study say that their results cast doubt on whether doctors should continue prescribing Avandia given the increased risk of side effects uncovered by their research.

In the study published in the online version of the British Medical Journal, scientists examined the medical records of nearly 40,000 patients who were prescribed either Avandia or the diabetes medication Actos. Patients in the study who were treated with Avandia were significantly more likely to have had experienced heart attack or death than patients who were treated with Actos.

Concerns about Avandia first arose in May 2007, when a study published in the New England Journal of Medicine uncovered an increased risk of heart attack or cardiovascular death that Avandia users suffered. The study found that patients taking Avandia were 43% more likely to suffer a heart attack and 63% more likely to die from cardiovascular problems than patients who were given another drug or a placebo.