Coca tea consumption causes positive urine cocaine assay.

Background: Coca tea, derived from the same plant that is used to synthesize cocaine, is commonly consumed in South America and easily obtained in the United States.
Objectives: To determine whether consumption of coca tea would result in a positive urine toxicology screen for cocaine metabolites.
Methods: Five healthy adult volunteers consumed coca tea and underwent serial quantitative urine testing for cocaine metabolites by fluorescence polarization immunoassay. The cutoff for a positive assay was chosen at 300 ng/ml, the National Institute on Drug Abuse standard.
Results: Each participant's urine cocaine assay was positive (level exceeding 300 ng/ml) by 2 h after ingestion. Three out of five participants' samples remained positive at 36 h. Mean urine benzoylecgonine concentrations in all postconsumption samples was 1777 ng/ml (95% confidence interval: 1060-2495).
Conclusions: Coca tea ingestion resulted in a positive urine assay for cocaine metabolite. Healthcare professionals should consider a history of coca tea ingestion when interpreting urine toxicology results.