The launch of a new flu drug could bring chaos to Bradford GP surgeries, a doctor has warned.

Dr Ian Fenwick from the New Cross Street Health Centre said GPs were worried that there could be a high level of demand for Relenza which is available from Monday.

The drug is said to be a ground-breaking treatment with the potential to save lives and the ability to shorten the duration of flu by up to two days if taken soon after symptoms appear.

But GPs fear patients with common colds will go to see them inappropriately.

Dr Fenwick said: "It's going to be chaotic - very similar to the Viagra fiasco.

"I think there's worry that there will be a lot of demand and how are we supposed to respond to that when we haven't been given any directions?"

Dr Fenwick said there was a fiasco around the impotence drug Viagra because guidelines for its use were not published before its launch.

He said that made GPs' lives difficult because patients were asking for it but doctors were not sure who they should be prescribing it for.

The guidelines for Relenza are not due to be published by the National Institute for Clinical Excellence (NICE) until November.

Dr Fenwick said years spent by GPs encouraging people to treat themselves could be destroyed because people could turn up at surgeries with all sorts of viruses believing the new flu drug would help them.

But he said the drug would be good news for frail, elderly people and people with heart and breathing problems who are at risk if they get flu.

According to a confidential report seen by Doctor - a weekly medical newspaper for GPs - 4.8 million people could need Relenza during an epidemic year. As the drug costs £24 per dose, it could cost the NHS up to £115 million.

However, a spokesman for Relenza manufacturer, Glaxo Wellcome, said they did not expect more than 500,000 people to receive the drug in an average year, restricting the cost to £12 million.

A Department of Health spokeswoman said: "NICE will be reviewing it and reporting back to us about how it should be administered."

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