Pressor and Diminished Local Vasoconstrictor Effects of Levarterenol-Phentolamine Mixtures

Levarterenol ( l -norepinephrine [Levophed]) bitartrate is one of the most commonly used pressor amines in the treatment of shock. However, a major disadvantage is the development of ischemic necrosis in areas of accidental extravasation. On the basis of clinical use, starting in 1954, it was demonstrated by one of us 1 that, in such areas, the local vasoconstrictor effect could be counteracted by phentolamine (Regitine) methanesulfonate, an antiadrenergic drug. When 5-10 mg. of the latter drug, diluted in 20 cc. of water, was infiltrated subcutaneously throughout the area of ischemia, the pallor and coldness disappeared within five to seven minutes. Untreated areas became necrotic. Similar observations have been made by McGinn and his co-workers, 2 who added hyaluronidase to the phentolamine solution. Pelner 3 cited a case in which hyaluronidase favored the spread of ischemia. He also reported that another antiadrenergic drug, piperoxan (Benodaine), had an action similar to that