Kroll M H, Nealon L, Vogel M A, Elin R J
Clin Chem. 1985 Feb;31(2):306-8.
Phenacemide and cephalothin may interfere either positively or negatively with the determination of creatinine by the Jaffé reaction, depending on the analytical system. The drug-picrate chromophores maximally absorb within the first minute of reaction (21 s for phenacemide, 45 s for cephalothin), after which the absorbances decrease. Thus, these drugs negatively interfere in analytical systems involving kinetic measurements when the time interval of measurement includes the period of decreasing absorbance.
