Proposed Sars treatment could be used with Ribavirin, say HK experts

A new drug treatment being proposed by world-famous HIV researcher David Ho Ta-yi should be used to supplement, not replace, the current Ribavirin treatment given to Sars patients in Hong Kong, local medical experts said yesterday.

The comments came after doubts were cast on the Hong Kong treatment method by the World Health Organisation, the US Centres for Disease Control and Prevention and a panel of experts on Canada's Sars Scientific Advisory Committee.

Protease inhibitors, a type of virus-fighting drugs pioneered by Dr Ho in HIV treatment, have been proposed to try on patients who do not respond to the combination of the powerful anti-viral drug Ribavirin and steroids.

Legislator and Medical Association President Lo Wing-lok said that since the Sars-causing coronavirus and the HIV virus both use RNA to carry genetic material instead of DNA, which is found in nearly all other life forms, the drug strategy used to treat HIV may be applied to Sars cases. He predicted the new treatment could be available in several weeks. Both viruses have no DNA; they use only RNA to produce proteins and replicate.

'We already have the drugs. There is nothing to lose in trying [protease inhibitors] on patients who fail to respond to the current treatment,' said Dr Lo, who said the new treatment could start as soon as the ethics committees at the two teaching hospitals, Prince of Wales and Queen Mary, approve it.

Chinese University biochemist Wong Kam-bo said Ribavirin and protease inhibitors target two different stages of viral reproduction, and both stages work similarly in the HIV and Sars viruses.