Performance of a new automated substrate-labeled fluorescence immunoassay system evaluated by comparative therapeutic monitoring of five drugs.
The analytical performance of a new automated substrate-labeled fluorescence immunoassay system (Ames TDA/Optimate) was evaluated by comparative therapeutic drug monitoring of carbamazepine, phenobarbital, phenytoin, theophylline, and quinidine. Using Optimate, the coefficients of variation of the within- and between-run variability in the lower therapeutic range were 4.8 and 4.7%, respectively, for carbamazepine (by high-performance liquid chromatography (HPLC): 4.3 and 8.2%), 4.5 and 7.2%, respectively, for phenytoin (by gas-liquid chromatography (GLC): 1.9 and 6.2%), 2.4 and 2.9%, respectively, for phenobarbital (by GLC: 11.4 and 14.7%), 3.2 and 4.6%, respectively, for theophylline (by HPLC: 7.2 and 12.5%), and 3.0 and 22.8%, respectively, for quinidine (by fluorometry: 3.0 and 4.2%). Stored calibration curves in connection with a normalization factor could be used for at least 4 weeks for the measurement of human specimens. Linear regression analysis of parallel therapeutic drug level monitoring demonstrated good agreement between the Optimate (y) and comparative technique (x) for each drug. The corresponding expressions for carbamazepine are y = 0.85x + 0.49 (r = 0.09, n = 44), for phenobarbital y = 0.99x + 0.75 (r = 0.98, n = 45), for phenytoin y = 0.97x - 0.35 (r = 0.99, n = 50), for theophylline y = 1.0x + 0.43 (r = 0.99, n = 44), and for quinidine y = 0.94x + 0.11 (r = 0.96, n = 32).(ABSTRACT TRUNCATED AT 250 WORDS)
D001322:Autoanalysis / Q000379:methods; D002220:Carbamazepine / Q000097:blood; D002849:Chromatography, Gas / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004355:Drug Stability; D005455:Fluorescent Antibody Technique; D006801:Humans; D004364:Pharmaceutical Preparations / Q000097:blood*; D010634:Phenobarbital / Q000097:blood; D010672:Phenytoin / Q000097:blood; D011802:Quinidine / Q000097:blood; D013050:Spectrometry, Fluorescence / Q000379:methods; D013806:Theophylline / Q000097:blood
D004364:Pharmaceutical Preparations; D002220:Carbamazepine; D010672:Phenytoin; D013806:Theophylline; D011802:Quinidine; D010634:Phenobarbital