Tissue injuries associated with parenteral propylhexedrine abuse

Propylhexedrine, the active ingredient in Benzedrex Inhalers, is extracted from the wicks of the inhalers by drug abusers for intravenous injection to provide a "desirable high." Six representative cases treated over a one-year period are presented to exemplify the potential for soft tissue injury. Because the actual constituents of the injected material prepared from the inhalers were not established, solutions were prepared from Benzedrex Inhalers according to the formula provided by one of the patients. The extract was then subjected to vigorous qualitative and quantitative analyses; the presence of essentially pure propylhexedrine hydrochloride was confirmed in varying concentrations. To examine the progression of injury following injection of the prepared extract, the ears of 12 New Zealand white rabbits were injected either intra-arterially or subcutaneously. The opposite ear of each rabbit served as a control. Both clinical and pathologic observations demonstrated injury consistent with intense local vasoconstriction. Injury did not appear to relate to impurities in the solution or other embolic phenomena. Finally, the laboratory findings are discussed with regard to the clinical examples. In sum, the insult to tissue from intravascular or local injection with propylhexedrine appears to respond, although poorly, to efforts to reverse the intense pharmacologic vasoconstriction.