Stabilization and quantitative determination of disulfiram in human plasma samples

The rapid reduction of disulfiram at therapeutic plasma concentrations was inhibited by addition of the chelating agent, diethylenetriamine pentaacetic acid, and acidification in the presence of sodium chloride. The disulfiram recovery at concentrations ranging from 0.100-0.800 mumol/l was about 100% when preserved at 4 degrees C and analyzed immediately, and 95% and 75% after preservation for 1 h at 4 degrees C and for 24 h at -20 degrees C, respectively. The concentrations of disulfiram were determined in plasma from alcoholics receiving repeated therapeutic doses of disulfiram. Detectable concentrations in the range of 0.100-0.200 mumol/l could not be obtained until the second week of treatment.