Oral fluid results compared to self reports of recent cocaine and heroin use by methadone maintenance patients

Abstract

Although self reports of illicit drug use may not be reliable, this information is frequently collected and relied upon by national drug surveys and by counselors in drug treatment programs. The addition of oral fluid testing to these programs would provide objective information on recent drug use. The goal of this study was to compare oral fluid tests for cocaine, benzoylecgonine, 6-acetylmorphine, morphine, codeine and 6-acetylcodeine to self reports of recent cocaine and heroin use by patients in an outpatient methadone treatment program. Patients (n=400) provided an oral fluid specimen and completed a short questionnaire on illicit drug use over the last seven days. Oral fluid was collected with the Intercept Oral Fluid Collection device. Oral fluid was analyzed by a validated assay using liquid chromatography coupled with tandem mass spectrometry. The presence of an analyte was confirmed if all identification criteria were met and its concentration (ng/mL) was ≥ LOQ (cocaine, 0.4; benzoylecgonine, 0.4; morphine, 2; codeine, 2; 6-acetylmorphine, 0.4; and 6-acetylcodeine, 1). Analyses of oral fluid specimens collected from the 400 methadone maintained patients revealed that a majority (95%) of subjects who admitted to recent cocaine use were confirmed positive, whereas slightly more than 50% were confirmed positive who admitted to heroin over the last seven days. For those patients who denied recent cocaine and heroin use, approximately 30% were positive for cocaine and 14% were positive for heroin. Oral fluid testing provides an objective means of verifying recent drug use and for assessment of patients in treatment for substance use disorders.