INTERFERENCE OF METAMIZOL (DIPYRONE) ON THE DETERMINATION OF CREATININE WITH THE KODAK DRY CHEMISTRY SLIDE COMPARISON WITH THE ENZYMATIC METHOD FROM BOEHRINGER

In order to eliminate positive interferences that take place with the Jaffe technique, the Kodak Ektachem and Boehringer Mannheim Companies have chosen an enzymatic method for the determination of creatinine in serum and urine. Pathological and clinical samples often contain meta bolites in elevated concentrations or exogenous compounds such as drug s or toxic compounds. We noticed that patients receiving metamizol-con taining drugs showed unusually low values of creatinine when determine d with an Ektachem analyser. We investigated the effect of the main me tabolites of this prodrug on the creatinine enzymatic methods of Kodak and Boehringer. We concluded that methyl-amino-antipyrine, the active substance after administration of metamizol (prop. INN) was responsib le for the interference, and that no reliable determination of creatin ine could be performed with these methods in the serum of patients rec eiving this drug.