Screening for illicit heroin use in patients in a heroin-assisted treatment program.

The aim of this study was to investigate the use of illicit heroin among patients in a heroin-assisted treatment program. In this program, pharmaceutical-grade heroin was administered to heroin-addicted patients. Monitoring of illicit heroin use was considered important for the evaluation of this treatment program. Acetylcodeine and codeine, common adulterants of "street" heroin, were used as markers for illicit heroin. A liquid chromatography method with tandem mass spectrometric detection (LC-MS-MS) was developed, for quantitative analysis of heroin and methadone, their metabolites, and the simultaneous detection of acetylcodeine. One-hundred patients in a heroin-assisted treatment program were screened for acetylcodeine in plasma. Furthermore, patients were interviewed about illicit heroin use, and they were tested for alcohol and cocaine use. In plasma samples of 16% of the patients, acetylcodeine was detected. Overall agreement between self-report and plasma samples was 95% (kappa: 0.81). Patients who tested positive for acetylcodeine had visited the outpatients' clinics significantly less frequently than the patients who tested negative. Alcohol and cocaine use was more common in patients who tested positive for acetylcodeine. Illicit heroin use was observed in a limited percentage of patients. Overall agreement between self-report and markers of illicit heroin use was good.