1989 – False benzodiazepines results in a rapid immunochromatography test for urinary drug detection in tobacco smokers

Background This study aimed to evaluate the interference of tobacco smoke on immunochromatography assay for urinary benzodiazepines detection and the interest of two biological markers and smoking status parameters as predictive factors of false results. Methods Our study included 256 voluntary subjects (143 passive smokers and 113 smokers). Cotinine was measured by homogenous immunoenzymatic assay and SCN- by selective electrode. Urinary drugs were detected by immunochromatographic assay. A positive result is completed by an analytical method with an immunometric assay. Results False positive results for benzodiazepines are significantly more frequent in smokers compared with passive smokers (90.2% Vs 22.4%, p Conclusions Tobacco smoke interferes with immunochromatographic assay of urinary drug detection; therefore, all subjects must be questioned about their smoking status to avoid such false results during results interpretation.