Cocaethylene presence in oral fluids from cocaine users

Abstract

Simultaneous consumption of cocaine and alcohol is very common amongst cocaine users and many addiction centres now warn of the dangers of combined consumption of cocaine and alcohol. Research by the National Treatment Agency highlighted that 61% of powder cocaine users always use alcohol at the same time. Another study published in Italy reported 5.6% of drivers under the influence had consumed both alcohol and cocaine (Snengi R., Alcohol and alcoholism, 2018, 53(6):735–741). It is well documented that the use of alcohol with cocaine has serious additive effects such as increased cardiotoxicity, cardiovascular effects and prolonged euphoria. Simultaneous consumption of cocaine and alcohol results in the formation of cocaethylene, the ethyl ester of benzoylecgonine. Cocaethylene is pharmacologically active, and its pharmacological activity is similar to that of cocaine. In this study we evaluated the commercially available screening tests to understand their ability to cross-react with cocaethylene. We also analysed data from over 14,000 oral fluid samples submitted for cocaine analysis from drug treatment and probation sites in the UK. Available commercial screening product inserts were reviewed to assess reported cross-reactivity of the cocaine assay with cocaethylene. Confirmation data from oral fluid samples received at Abbott Toxicology, UK between January 2019 and April 2022 was reviewed. All samples had been collected using the Certus Oral Fluid Collection device and analysed using LC- MS/MS for cocaine, benzoylecgonine, norcocaine, cocaethylene as well as anhydroecgonine methyl ester. Cross-reactivity data from commercial products showed that there was a large variation in cross reactivity to cocaethylene between different vendors ranging between 4%–80%. The assay target was either benzoylecgonine or cocaine. Several product inserts did not list cocaethylene under the assays cross reactivity information. In total, 14,842 samples were received in the laboratory, of which 75% ( n = 11,194) were positive for either cocaine or one of its metabolites. Cocaine was present in 98% ( n = 11,019), benzoylecgonine in 89% ( n = 10,017) and cocaethylene in 6.6% ( n = 740) of the positive samples. The longer lasting and increased effects of cocaethylene may cause prolonged impairment. The data presented highlights that the cross reactivity to either cocaethylene or benzoylecgonine should not be a forgotten while developing cocaine testing strategy.