Who gets the medicine? NHS funds are not limitless and the rising cost of medical progress is increasingly forcing this question onto the health agenda.

Beta-interferon: Restricted use

Until now doctors and health authorities have had to make decisions on whether they can afford new drugs, leading to accusations that their availability depends on where you live.

Decisions should be based on clinical issues and not just cost, but there are suspicions that decisions are often dictated by budgets.

Health Secretary Frank Dobson's decision to impose a temporary ban on Viagra based on its cost is effectively the first step towards the creation of a national policy on drug availability on the NHS.

National guidance

Mr Dobson said the anti-impotence drug would not be available on the NHS until his team of ministers had consulted "further expert guidance" over the cost of treatment.

The Department is expected to issue strict guidelines defining exactly who gets the drug and who is allowed to prescribe it.

The DoH has long denied that rationing exists in the NHS.

But now health ministers accept that the plethora of costly modern medicines available put the NHS at risk, a spokesman said.

He added: "In the longer term, we are putting together plans for the National Institute of Clinical Excellence [to decide which drugs should be available on the NHS] so we do not have medicine by postcode."

Ensuring clinical need

He said "substantive guidance" would be issued to ensure that those with a real clinical need got Viagra.

Angela Coulter: "I hope this will extend to other drugs"

The Institute will assess all new drugs in this way when it becomes operational in the next two years or so.

Angela Coulter: Pleased

Angela Coulter, of the King's Fund health research body, said the government approach was refreshing and she hoped it would extend to other drugs.

A spokeswoman for the British Medical Association said the move was welcome.

"We believe that rationing decisions, if they have to be made, should not be made in the consulting room.

"They should be made at a national level."

She added: "It is quite a dramatic moment in the history of the NHS because, up until now, as soon as a drug was licensed it was available on the NHS."

The BMA hopes the guidance will be specific enough to remove this burden from doctors. "If the guidelines say A, B, C, D, E and your patients do not fall into all those categories, then you can turn to your patient with a clear conscience and say no."

The government's announcement is an acknowledgement that priorities have to be set.

Expensive treatments

However, the Association of the British Pharmaceutical Industry attacked the witholding of any treatment at a national level.

It pointed to evidence suggesting that expensive treatments are cost-effective in the long term.

The Association's study showed that a �3,600 course for hepatitis C could cure the disease in a quarter of all cases.

If left untreated, hospitalisation and other costs escalated to more than �50,000 per patient.

Controversy has long surrounded the availability of expensive new drugs on the NHS.

The multiple sclerosis treatment beta-interferon, which costs approximately �10,000 per patient per year, has proven benefits for some MS sufferers.

In 1995, the NHS Executive issued guidelines for prescribing beta-interferon, but doctors and patients claimed the advice was too vague.