Monitoring pediatric serum theophylline, phenobarbital, and phenytoin with the IL Multistat III.

We compared results of theophylline, phenobarbital, and phenytoin assays by the EMIT method using the IL Multistat III Micro Centrifugal Analyzer with results by the EMIT semiautomated procedure on a Beckman 25 spectrophotometer equipped with a semiautomated pipettor-dilutor and a model 2400 automatic timer/printer. We assessed linearity, precision, specificity, and correlation with other methods, The IL MCA III is precise, easy to use, and suitable for routine use in a pediatric laboratory. Only 3 microliter of serum is used for each drug analysis, and 17 results can be obtained in 8 min. Reagent costs can be reduced fourfold.