National Health Service prescribers have now been told that they should not prescribe Relenza (zanamivir) for patients with influenza unless, in their clinical judgment, they believe that they should.
This confusing advice has been set out in a document issued to the National Health Service by the National Institute for Clinical Excellence on October 8. The document says that that individual professionals "have a responsibility to exercise clinical judgment in deciding what treatments are appropriate and necessary for patients with influenza-like symptoms".
After saying "this guidance does not override that individual responsibility", the NICE document says: "The institute advises that health professionals should not prescribe zanamivir (Relenza) during the 1999-2000 influenza season."
It goes on to say that the National Health Service should encourage and, where possible, support Glaxo Wellcome in the conduct of four clinical trials of Relenza that are already being undertaken.
Summarising the findings of the NICE's rapid assessment committee (see panel for membership) the document says that the use of Relenza within 48-hours of the onset of influenza symptoms reduces the duration of the illness from a median duration of six days to five days.
It adds that limited numbers of high risk patients (particularly the elderly and those with cardiovascular disease, asthma, chronic obstructive pulmonary disease or immunosuppression) in clinical trials mean that the institute could not conclude that the frequency of serious secondary complications was reduced.
The institute estimates that the cost of to the NHS of Relenza, derived from estimates of the number of primary care consultations for influenza, would be £9.5m in a non-epidemic year and £15m in an epidemic year. It suggests that both these estimates might be low, because consultation rates might increase if Relenza was available.
The NICE document says that this guidance is only applicable to the 1999-2000 influenza season. A full appraisal of Relenza is expected to be carried out by the institute next year so that new guidance can be offered for the 2000-01 influenza season.
The guidance can be found on the institute's website at www.nice.org.uk.