FACTBOX-What's behind warning on bird flu drug Tamiflu?

(Reuters) - The Japanese government has ordered the importer of the bird flu drug Tamiflu to warn doctors against giving it to teenagers, the Health Ministry said on Wednesday.

Here are some key facts on Tamiflu and why warnings about its use have been called for:

SIDE EFFECTS?:

- According to Japan's Health Ministry, 54 people have died after taking Swiss drugmaker Roche's antiviral flu drug Tamiflu. Two young people who took it fell to their deaths in February 2007 in suspected suicides and two others were injured in similar incidents.

- The drug's possible side effects first came to light in Japan in 2005, after 12 children died and 32 experienced abnormal behaviour after taking it.

- Japan's warning will recommend the drug is not prescribed to minors over the age of 10, unless a case is judged high risk.

U.S, CANADA, AND JAPAN ASK FOR WARNINGS:

- In early November 2006 U.S. regulators announced Tamiflu would come with a new caution urging close monitoring of patients for abnormal behaviour, based on more than 100 international reports of side-effects such as hallucinations, panic attacks, convulsions and self-harm.

- Later the same month Health Canada also asked Roche to include a warning on Tamiflu's possible health risks.