Metabolism of intranasally applied cocaine.

Surprisingly little is known about the metabolism and toxicity of cocaine in man. In this study serum obtained following nasal surgery was assayed for benzoylecgonine (the major metabolite of cocaine) by radioimmunoassay. It was found that cocaine was rapidly hydrolyzed in the serum. Benzoylecgonine was detectable in the serum at 15 minutes. The peak blood level of the metabolite appeared at 4.5 hours with a peak concentrations of 872.9 ng/ml. The half time clearance of the metabolite from the serum was 5.5 hours. A discussion of variables which must be considered in deriving, by a scientific method, a maximum safe clinical dose is presented.