Etizolam, an anti-anxiety agent which is an antagonist of platelet-activating 
factor receptors, was administered to patients with chronic subdural hematoma 
(CSH) after hematoma removal to assess the effectiveness for preventing 
recurrence compared with control patients not given the drug after surgery. The 
remaining volumes of subdural hematomas on brain computed tomography were 
measured approximately 1 month after removal. Volume in the etizolam group (15 
patients) was significantly smaller than in the control group (24 patients). 
Hematoma recurrence was not detected in the etizolam group 3 months after 
surgery, but occurred in the control group. The difference was significant. 
Etizolam administration may be useful for the prevention of recurrence of CSH.