Methotrexate and cyclosporine are drugs most frequently monitored in our laboratory. We developed a tech- nique for the determination of both drugs by Emit reagents on the automated biochemical analyzer ADVIA 1650 Chemistry system. We evaluated within-run imprecision, the total imprecision, the linearity and the accuracy. We made also comparisons with the FPIA method and for methotrexate also with HPLC. Both methods meet requirements for drug monitoring and we can use them instead of the present methods. Cost savings is another benefit of the tested methods.

        Key words: cyclosporine, methotrexate, determination.