Development and evaluation of a compliance test for patients taking disulfiram

A breath test for carbon disulfide, a major excretion product of disulfiram, is described and evaluated. All breath excretions were standardized by collecting a fixed amount based on CO2 control. Excretion of CS2 falls rapidly (half life 8 to 18 hours), so that 20 to 30 hours following the last dose of disulfiram the test becomes negative. Approximately 300 tests in hospitalized patients taking disulfiram were positive; 40 tests in patients not taking this drug were negative. In an active disulfiram outpatient clinic more than one third of the patients who claimed to have taken disulfiram on the previous day had, as determined by this test, failed to do so. Of subjects judged by the professional staff to be almost certainly compliant 20% were not taking medication. Of the total of 52 patients tested in clinic only 25 were taking disulfiram.