Elimination kinetics of disulfiram were determined in 15 male alcoholics after 250 mg disulfiram taken by mouth as a single dose and again after 12 days of dosing. Apparent t 1/2s were calculated for disulfiram, diethyldithiocarbamate (DDTC), diethyldithiocarbamate-methyl ester (DDTC-Me), diethylamine (DEA), and carbon disulfide (CS2) and were found to be 7.3, 15.5, 22.1, 13.9, and 8.9 hr. Elimination t 1/2 for CS2 in breath was 13.3 hr. Average time to reach maximal plasma concentration after either single or repeated doses was 8 to 10 hr for disulfiram, DDTC, DDTC-Me, DEA, and CS2 in breath, while plasma CS2 concentration peaked 5 to 6 hr after disulfiram. In these studies, 22.4% and 31.3% of the disulfiram after single and repeated dosing was eliminated in the breath during one dosing interval. In urine, 1.7% and 8.3% of the disulfiram dose was eliminated as DDTC-glucuronide after single and repeated dosing, while DEA accounted for 1.6% and 5.7% of the dose. There was marked intersubject variability in plasma levels of disulfiram and its metabolites. This variability may be the result of the lipid solubility of disulfiram, differences in plasma protein binding, or the effect of enterohepatic cycling.