The health ministry was 'negative' in 2006 on the possibility of a causal relationship between the influenza drug Tamiflu and abnormal behavior, despite reports from at least two doctors who said such links could not be denied in the deaths of two teenagers, medical and pharmaceutical sources said Monday. </PARAGRAPH> <PARAGRAPH>It is not known why the Health, Labor and Welfare Ministry decided to frown on the possibility of causal links because the ministry said it does not have any documents that would lead to such a conclusion, the sources said.</PARAGRAPH> <PARAGRAPH>In reports filed with the Pharmaceuticals and Medical Devices Agency, a government body that collects and provides information on the side effects of drugs, Chugai Pharmaceutical Co. &#8212; the importer and distributor of Tamiflu in Japan &#8212; attached opinions from two doctors who entertained the possibility that causal relationships could have been a factor in two Tamiflu cases in 2004 and 2005.</PARAGRAPH> <PARAGRAPH>The 2004 case involved a 17-year-old male high school student in Gifu Prefecture who is known as the first fatal case of abnormal behavior related to the use of Tamiflu.</PARAGRAPH> <PARAGRAPH>A report on the case submitted to the agency by Chugai Pharmaceutical says the youth developed a fever and was treated at a hospital in early February 2004.</PARAGRAPH> <PARAGRAPH>Hours after taking Tamiflu, the student, who was diagnosed with influenza, dashed out of his home barefoot in the snow, climbed over a guardrail and onto an expressway where he was hit by a truck and killed.</PARAGRAPH> <PARAGRAPH>In an opinion attached to the report, the doctor who treated the student said he does not think the teen developed influenza-caused encephalopathy because he was clear-headed and talked with hospital staff before taking the drug.</PARAGRAPH> <PARAGRAPH>The student 'showed the abnormal behavior about two hours after taking –

so that the causal links with it cannot be denied," the doctor said in the opinion.

The 2005 case involved a 14-year-old male junior high school student in Aichi Prefecture who jumped to his death from an apartment.

In a report on the case by Chugai Pharmaceutical, the doctor who was in charge of the teenager said: "What I can say is that the use (of Tamiflu) might be linked. It is unclear whether the student's fall was caused by side effects (of the drug)."

In January 2006, the health ministry said that after hearing the opinions of numerous experts, it was "negative" to possible causal relationships between Tamiflu and abnormal behavior.