In Japan, intravenous alteplase, a recombinant tissue-type plasminogen activator 
(rt-PA), was approved for an indication of ischemic stroke in 2005 on the basis 
of the results of a clinical trial with a unique dose of the drug (0.6 mg/kg). 
The Japan Stroke Society published the guidelines for intravenous application of 
rt-PA and organized training sessions for proper use all over Japan in an effort 
to promote the safe, widespread use of intravenous alteplase. Seven years 
following its approval, clinical experience with intravenous alteplase has 
accumulated, additional evidence of intravenous alteplase has been found in 
Japan and overseas, and the medical environment has substantially changed, 
including approvals for new drugs and medical devices. Notably, the use of 
alteplase in the extended therapeutic time window (within 4.5 hours of symptom 
onset) became covered by insurance in Japan in August 2012. To address these 
changing situations, we have decided to prepare the revised guidelines. In 
preparing the second edition, we took care to make its contents more practical 
by emphasizing information needed in clinical practice. While the first edition 
was developed with emphasis on safety in light of limited clinical experience 
with intravenous alteplase in Japan in 2005, this second edition is a 
substantial revision of the first edition mainly in terms of eligibility 
criteria, on the basis of accumulated evidence and the clinical experience.