Glitazones no better than older, cheaper antidiabetic drugs
Glitazones are no better than older, cheaper oral antidiabetic drugs and are not worth the huge NHS expenditure that is spent on them, a review has concluded.
It came as a prescribing advisory committee urged GPs not to prescribe rosiglitazone because of ‘inadequate evidence for efficacy and safety'.
The review, in April's Drugs and Therapeutics Bulletin, warned that glitazones offered no real clinical advantage over metformin or sulphonylurea when used on their own, or in combination as a triple therapy.
The bulletin questioned the amount the NHS spends on glitazones, which account for more than half its expenditure on oral hypoglycaemic drugs – at a cost of more than £19m every year.
It added: ‘There is no convincing evidence that glitazones offer any benefits over metformin or a sulphonylurea in terms of improved clinical outcomes when used as monotherapy. Evidence for their use in triple therapy is also weak.' If a glitazone was thought to be necessary, ‘pioglitazone is probably safer', it said.
The Midlands Therapeutic Review and Advisory Committee last week said it had reviewed the use of rosiglitazone following ‘new warnings regarding safety' and that the drug ‘cannot be recommended because of inadequate evidence for efficacy and safety'.
The number of patients prescribed rosiglitazone has plunged by nearly a third in less than a year – from 95,472 in May 2007 to 65,331 in February 2008. By contrast the number of patients prescribed pioglitazone has risen from 50,796 per month to 64,719 over the same period.
Dr Ike Iheanacho, editor of the Drugs and Therapeutics Bulletin, told Pulse that the glitazones had failed to live up to their hype. ‘When they first came on out everyone thought they would be marvellous but actually the evidence is that it is for their use as a monotherapy or in combination as part of a triple therapy is quite weak.'
‘Given the limited circumstances in which they are effective and the problems that come with glitazones, it's our view that it's hard to reconcile them having such a huge budget.'
Dr Brian Karet, a GPSI in diabetes in Bradford, agreed. ‘The current usage is in excess of what can be justified. I think the place of the glitazones is extremely limited – there are other new drugs which admittedly don't have long-term outcome data but don't have the safety concerns that the glitazones do.'
A spokesperson for GSK said the European medicines regulatory agency concluded in October last year that the benefits of rosiglitazone in type 2 diabetes continued to outweigh its risks.
The spokesperson added: 'GlaxoSmithKline believes that rosiglitazone remains a valuable medicine for many patients with type 2 diabetes and an important treatment option for doctors, when used appropriately, and that the decision about a patient's treatment should be made by the doctor, in consultation with the patient and in line with the prescribing information.'Diabetes consultation