Plan to stock up on single flu medicine challenged

Selected drug shows no advantage over alternative remedy, says medical expert

Questions were raised yesterday on plans to spend millions of dollars to stockpile a single drug to be used in the event of a flu pandemic.

Hong Kong has already stockpiled 3.7 million tablets of the anti-flu drug Tamiflu and will seek legislative approval next month for $254 million to buy an additional 16.8 million tablets.

With 20 million tablets to be maintained in the stockpile, the controller of the Centre for Health Protection, Leung Pak-yin, said this meant that 30 per cent of the population would be covered, one of the highest rates in the world.

Normal treatment requires two tablets a day for five days. Poultry workers involved in culling would be given one tablet daily during the operation, and seven days' medicine after that, Dr Leung said. Close contacts of infected people would need daily tablets for seven days. Workers at elderly homes might be given one tablet a day for 14 days.

But Kenneth Tsang Wah-tak, professor of respiratory and critical medicine at the University of Hong Kong, questioned the scientific basis for choosing Tamiflu when a second drug, Relenza, is available.

'The only people who have used Tamiflu - Thais and Vietnamese, along with a handful of Hong Kong people in 1997 - showed that Tamiflu does not show any particular efficacy,' Professor Tsang said.

'It may or may not be due to late use or due to the high mortality rate for H5N1 anyway.'

He suggested clinical trials be conducted on combining the two drugs.

The president of the Hong Kong Medical Association, Choi Kin, said private doctors had been advised by the centre to stockpile Tamiflu.

Relenza might not work for elderly and young people who might have difficulty inhaling the drug as required, Dr Choi said.

Professor Tsang disputed this, saying that Relenza was similar to inhalers used by asthmatics. 'So it is quite easy to use,' he said.

In a letter in last week's issue of the journal Nature, Australian flu expert Graeme Laver said the two drugs offered some protection against all flu viruses, including the deadly H5N1 strain.

Dr Laver, whose work led to the development of the drugs, said that to be effective, Tamiflu had to be given either before infection or very soon after flu symptoms appeared.

'A more effective use would be to have Tamiflu available over the counter in local pharmacies, coupled with a rapid, sensitive and accurate flu diagnostic test,' he said.

He said public health measures such as quarantine and travel restrictions 'are unlikely to be more effective [against a flu pandemic] than a garden hose in a forest fire'.

A centre spokesman said it would take into account the actual situation in refining strategy.