Treatment of severe shock with phenoxybenzamine

Phenoxybenzamine is a safe and effective vasodilator which usually causes an increase in arterial blood pressure, an increase in cardiac index, an increase in urine output and a decrease in pulmonary artery pressure and central venous pressure in states of severe shock if hypovolemia has been corrected. Phenoxybenzamine does not produce detrimental effects if given in appropriate instances. Phenoxybenzamine should be given only after other appropriate treatments, including adequate intravenous volume administration, have failed to produce an adequate arterial blood pressure and urinary output. It should be given only in the presence of a high normal central venous pressure and a high pulmonary artery pressure. Its administration should be closely monitored. It may be repeated once or twice at 24 hour intervals, if necessary. At present, phenoxybenzamine is available for intravenous use only as an investigative drug.