The activity of antibody-bound alkaline phosphatase (ALP) was measured with the enzyme cycline method using ELISA with polystyrene microtiter wells coated with antibenzoylecgonine antibody and ALP-labeled benzoylecgonine. The range of benzoylecgonine measurable by ELISA was 12 pg-25 ng well; the analysis time for 96 wells was 96 minutes. In LAIRT, the agglutination reaction with antibenzoylecgonine and antibody- coated latex and benzoylecgonine-rabbit serum albumin conjugate- coated latex was inhibited by 0.1 microgram benzoylecgonine/ml urine; the analysis time for six samples on one glass side was 20 minutes. Urine samples of 47 drug abusers were analyzed by ELISA and LAIRT, and findings were compared with results of the enzyme- multiplied immunoassay technique and gas chromatography-mass spectrometry. It was found that both ELISA and LAIRT were suitable as a urine sample screening method. 9 references, 2 tables, and 2 figures