After the wonder drug comes the "wonder why" drug. The National Institute for Clinical Excellence (Nice), the Government's watchdog on clinical effectiveness, is to switch its attention from useful treatments to useless ones in an attempt to save the NHS millions.

After seven years in which it has assessed new drugs and treatments such as Herceptin for breast cancer and decided which ones should be approved for use on the NHS, Nice is to "rebalance" its work to spend more time deciding which older treatments should be abandoned.

Among the first in its sights will be antibiotics prescribed to children with sore throats, which are mostly caused by viruses on which antibiotics have no effect.

One third of the 540,000 children who consult GPs each year with sore throats are prescribed antibiotics at a cost of £11.5m. A 50 per cent reduction could save the NHS more than £5m.

Launching the initiative yesterday, Andy Burnham, a Health minister, said that it was not about "cutting services" and pledged that any savings would be "redirected to more effective forms of patient care". He cited unnecessary tonsillectomies and hysterectomies, highlighted by the chief medical officer, Liam Donaldson, in July, as procedures which were being regularly performed at an annual cost of £21m despite other, less invasive, treatments being available.

The idea of cutting treatments, even useless ones, has been regarded as too politically sensitive until now. Andrew Dillon, chief executive of Nice, said the institute had been pressing to extend its remit to cover useless treatments and the financial crisis in the NHS had made it possible. Mr Dillon said: "Nice already advises the NHS on when it should invest in new drugs. It is common sense for us to also advise on when it is appropriate to stop using treatments. It won't solve the financial crisis, but it could help."

The British Medical Association warned against "blanket bans" on treatments. Sam Everington, deputy chairman, said: "There may be occasions where individual patients with specific health needs would necessitate a particular intervention. Any decision must be based on clinical evidence and not simply on cost-cutting."