Of 10 hypotensive drugs tested for control of exptl. hemorrhage in dogs, phenoxybenzamine-HCl (I) [63-92-3] (10 ml/kg, i.v.), cryptenamine acetate [55963-37-6] (i.v. infusion), diazoxide [364-98-7] (300 mg, i.v.) and nitroprusside Na [14402-89-2] (i.v. infusion) were the most effective.It appears that any drug which will produce satisfactory hypotension is potentially useful in the control of hemorrhage.