The 21-aminosteroids (lazaroids) are inhibitors of lipid membrane pero
xidation and appear to function as oxygen free radical scavengers. The
therapeutic potential of the lazaroid tirilazad mesylate has been ext
ensively studied in several CNS disorders, Tirilazad and related compo
unds have been found to be highly beneficial in spinal cord trauma. Sp
inal cord injury studies utilising tirilazad are currently underway to
determine the optimal combination of medications. Tirilazad has also
been found to be beneficial in experimental head injury models, howeve
r current clinical studies have failed to confirm this efficacy, due i
n part to difficulties in obtaining therapeutic drug concentrations, C
linical studies using tirilazad in subarachnoid haemorrhage have been
more promising, It has been shown to be beneficial in terms of reducin
g vasospasm and cerebral infarction associated with subarachnoid haemo
rrhage, and has now been approved in several European countries in thi
s indication. Results from US studies are expected shortly, Finally, t
irilazad has also been extensively tested in a variety of stroke model
s. Although it appears to be highly beneficial in experimental models,
the clinical studies to date have failed to confirm this efficacy, Ag
ain, this failure appears to be due largely to inadequate drug concent
rations having so far been tested.