24 January, 2009

Tamiflu: a drug for influenza A & B virus infection

The cost of this drug is relatively high. One capsule is 31 points (=310 yen) by
public insurance price. Taking 2 capsules/day for 5 consecutive days cost
3,100 yen (patient pay 30% of it, 930 yen in drug store since 70% is covered by

February 2001, Tamiflu (Trade name from Roche, Oseltamivir) was covered by
Public Health insurance in Japan. It is the main reason why Tamiflu are so
much prescribed in Japan.

Tamiflu capsule

Tamiflu Dry syrup for child.

1) Tamiflu and abnormal behavior:
The abnormal neurological symptoms(abnormal behavior) in children were noted
who took Tamiflu. Mass media picked up the typical case; a teenager who diagnosed
as influenza A infection by rapid antigen test and prescribed this drug by a practitioner.
After several hours taking Tamiflu, he/she jumped into the ground from the 10th's
mansion floor.

But the real causal relationship is remain obscure, since in some cases, influenza
virus infection itself cause the neurological complications, such as febrile convulsion
in infant (frequent), hallucination in children(sometimes) and acute encephalopathy
(rare) or hemorrhagic shock encephalopathy(very rare).

Before this drug was available in Japan, I also experienced the abnormal behavior
cases. For instance, 10 year old boy had high fever at morning and rest at bed.
Afternoon, he suddenly raised up the bed and rush to the outdoor. He lived in the
countryside and small river along in his house. So he run and jumped into the river.
The local doctor referred the boy to the University hospital. He was semi comatose
state at admission.The Electroencephalograph and Cerebral spinal fluid were normal.
Next morning, his consciousness returned to normal.

2) do not prescribed to one year old or younger ;
This recommendation is based the mouse experiment by the researchers of Hoffmann
La Loche announced that there are abnormally high CSF concentration of Tamiflu
in young rats.

Any questions: write to Keiji Hagiwara, MD