Acetylcodeine as a urinary marker to differentiate the use of street heroin and pharmaceutical heroin

Acetylcodeine (ACOD) is a synthesis byproduct present in street heroin but not in pharmaceutical diacetylmorphine (DAM) as used in the Swiss program Heroin-Assisted Treatment for Opiate Dependent Drug Users (HAT). ACOD was evaluated and validated as an urine marker to detect the consumption of street heroin by HAT participants. A gas chromatography-mass spectrometry method allowing the quantitation of ACOD concentrations as low as 0.2 ng/mL urine has been developed. In opiate-naïve subjects, intravenous (i.v.) ACOD showed a plasma elimination half-life of 237 ± 18 min, urine peak concentrations 2 h after administration, and a detection window of 8 h. Only 0.4 ± 0.1% was excreted unchanged, with codeine (COD) as the main metabolite. ACOD may be formed by transacetylation when i.v. DAM and oral codeine are co-administered. To avoid false-positive results, the calculation of COD/ACOD ratios is recommended. In a study with 105 HAT participants, 14% of the tested urines were ACOD positive. Only a low correlation was found between the anonymously self-declared consumption of street heroin and the ACOD positive rate.