Cocaethylene. What is it?

In this issue of the Journal, Thompson and Dasgupta describe the use of microwave irradiation to drive the derivatization of cocaine, its ethyl homologue and the major cocaine metabolites, benzoylecgonine and ecgonine methyl ester. Although more needs to be done to characterize the reaction, this interesting approach may have broad applications to the analysis of drug metabolites and other biologic compounds with appropriate functional groups. Also in this issue, Bailey has described the binding of cocaine and its ethyl homologue to serum proteins. While its binding to alpha-1 -acid glycoprotein and albumin, respectively, appears to be qualitatively similar to other basic drugs, cocaine appears to be less highly bound. Knowledge of binding to plasma proteins is fundamental to the understanding of the clinical pharmacology of any drug. What then do these two articles unexpectedly have in common? The authors of each saw fit to incorporate cocaethylene into their respective studies, and to cite it in the title. Because this compound is of relatively recent interest and may be unfamiliar to many readers of the two articles, a brief discussion of its neuropharmacologic properties and possible clinical significance may be helpful.