The calculation was made by the National Prescribing Centre in Liverpool, an advisory organisation, and sent to health service managers with a warning that the drug could "increase expectations dramatically".
Details of the report that were published in Doctor, the GPs' newspaper, show that 4.8 million people could need the drug in an epidemic year, based on the numbers of people currently chosen for vaccination. At a cost of pounds 24 per dose, it would mean a bill for the NHS of pounds 115.2m.
Relenza, manufactured by Glaxo Wellcome, is the first of a new generation of flu drugs. It has to be taken within the first couple of days of symptoms, but used twice a day for five days it can reduce flu symptoms. It is available in the United States.
A spokesman for Glaxo Wellcome said the company expected no more than 500,000 people to receive the drug in an average year, at a cost to the NHS of pounds 12m.
The National Institute of Clinical Excellence (NICE), a new body that recommends which medicines and therapies should be available on the NHS, is fast-tracking an investigation into Relenza to make proposals for its use by November, in preparation for the winter.
Dr George Rae, who chairs the prescribing sub-committee of the General Practitioners' Committee, told Doctor: "What we need from NICE are guidelines as to who would benefit from Relenza."
The drug is licensed for patients over 12 years old and recommended for those endangered by flu, such as the elderly and those with asthma and heart disease. Each year influenza claims more than 3,000 lives in Britain, mainly the elderly: nearly 150 million working days are lost because of it.
t Tony Blair sought to reassure the public over delays for hospital treatment yesterday. At his first official visit since his summer holiday, the Prime Minister announced 60 pilot projects for the on-the-spot computerised booking service for appointments and operations. The Government has already committed pounds 10m to 24 trial projects.
Ministers have come under fire because of their pledge to cut hospital waiting lists by 100,000: critics claim that waiting times are far more important to patients.Reuse content