The rapid reduction of disulfiram in blood and plasma

A gas chromatographic assay procedure was developed to quantitate the reduction product of disulfiram, diethyldithiocarbamate (DDC), in blood and plasma. The procedure involved the in situ methylation of DDC prior to the extraction and chromatography of the methyl ester. The minimal sensitivity achieved was 0.2 microgram/ml from 1 ml of blood or plasma. The coefficient of variation about any concentration was 10.5%. Calibration curves having a reproducible nonlinear form were prepared up to 9 microgram/ml. The assay procedure was used to evaluate the stability of disulfiram and DDC in blood. Disulfiram was rapidly and quantitatively reduced to DDC within 4 minutes. The DDC thus formed decomposed in human and dog blood with half-lives of 70 and 100 minutes, respectively. The implications of these findings are discussed with respect to the chemical form of disulfiram responsible for the ethanol-sensitizing effect.