Acetylcodeine as a marker of illicit heroin abuse in oral fluid samples

A method was developed using liquid chromatography linked to atmospheric pressure ionization-tandem mass spectrometry (LC-MS-MS) for the measurement of the opiates, morphine, codeine, 6-monoacetylmorphine (6-MAM), acetylcodeine (AC), and heroin in oral fluid collected from patients attending a substance abuse clinic. Of the 513 oral fluid samples tested, 297 showed detectable concentrations of 1 or more of the opiates and their respective percentage incidence being morphine (97%), codeine (82%), 6-MAM (77%), acetylcodeine (55%), and heroin (45%). A high percentage of these opiate-positive samples (40%) had detectable concentrations of all opiates tested. Significant correlations (p < 0.0001) were found between AC and 6-MAM (r = 0.95), heroin and 6-MAM (r = 0.81), and heroin and AC (r = 0.84). Although none of the subjects in this study were being treated with prescription heroin, nine showed detectable concentrations of heroin with no detectable AC. The mean concentration of heroin in these latter samples was very low compared with samples showing detectable AC (24 vs. 2571 microg/L). Several studies have reported the usefulness of measuring AC in urine for detection of illicit heroin abuse. This study demonstrates that the same marker can also be applied to oral fluid. The additional measurement of heroin in oral fluid is of limited use in monitoring subjects attending a substance abuse clinic.