[Nephelometric inhibition immunoassay (NIIA), a new methodology for the determination of phenobarbital and phenytoin concentration in serum (author's transl)].
Phenobarbital and phenytoin concentration was determined in serum by the aid of the nephelometric inhibition immunoassay (NIIA) and the homogeneous enzyme immunoassay (EMIT). Both methods showed a good precision and accuracy. The comparison of the two methods in 77 sera for phenobarbital (3--68 micrograms/ml) and 39 sera for phenytoin (1.3--44 micrograms/ml) showed a very close correlation. The correlation coefficient for phenobarbital was 0,9525 and for phenytoin 0,9714. The special merits of the NIIA-method were precision, less of interference and low costs in reagent material.