KUALA LUMPUR, MALAYSIA: Eminent virologist Emeritus Prof Datuk Dr Lam Sai Kit has expressed concerned that anti-virals like Tamiflu and Relenza could be abused if they are readily available over-the-counter.

"If any medication is overused and abused, and not prescribed by doctors, then the chances of the virus developing resistance is high.

"There are people who think that by taking Tamiflu, they can prevent the onset of flu but that is using the medication wrongly," Dr Lam, who is with Universiti Malaya's Institute of Research Management and Monitoring said.

He added that there were also people who quickly popped a Tamiflu in their mouths when they had ordinary flu, and by doing so, they might diminish the potency of the drugs.

Dr Lam, who was a director of the World Health Organisation's National Influenza Centre (Malaysia), said Tamiflu worked by killing the virus before it could go through its entire life cycle, thus preventing it from replicating or growing.

He said the majority of influenza infections did not require treatment with anti-virals since they were mild and confined to the upper respiratory tract and did not go down to the lungs.

He added that Tamiflu should only be used if there was evidence that the influenza is caused by something life-threatening, such as pneumonia or lung infection.

When asked if Tamiflu was still safe to be prescribed for children after recent reports of psychiatric disturbances, heart and lung disorders and deaths among 12 children, Dr Lam said the benefits outweighed the complications.

"WHO is still recommending its usage. The evidence is obviously not strong enough and the benefit far outweighs any rare complications," he said.

In 2008, the US Food and Drug Administration changed the drug's label to acknowledge reports of "delirium and abnormal behavior leading to injury, and in some cases, resulting in fatal outcomes," among flu patients taking Tamiflu. -Bernama