PROBLEM TO BE SOLVED : To provide pharmaceutical compositions and methods of treating traumatic brain injury (TBI), and pharmaceutical compositions and methods of treating a transient hypoxic and/or ischemic condition in the central nervous system. SOLUTION : The method comprises administering to a subject a therapeutically effective amount, specifically a dose of up to 40 mg, of phenoxybenzamine in a single dose within 24 hours, 16 hours or 8 hours after the onset of transient hypoxia and/or TBI, as an extended release formulation comprising a pharmaceutically acceptable carrier. SELECTED DRAWING : Figure 1 COPYRIGHT : (C)2019, JPO&INPIT