A DIRECT COMPETITIVE ELISA FOR THE SIMPLE, SENSITIVE AND ACCURATE DETERMINATION OF DIETHYLCARBAMAZINE CONCENTRATION IN SERUM

Improved methods for measurement of the anti-filariasis drug diethylca rbamazine in serum would assist in the design of effective therapy. Th e method evaluated in the present paper is a direct competitive ELISA which is sensitive, specific and accurate. Horseradish peroxidase-labe lled diethylcarbamazine conjugate was incubated with diethylcarbamazin e and anti-diethylcarbamazine antiserum over a bound second antibody. The enzyme activity of the remaining diethylcarbamazine-horseradish pe roxidase conjugate was measured. The intra-and inter-assay coefficient of variation was < 10% in the range of 1.0-30 ng ml(-1) and the limit of detection was 0.3 ng ml(-1). The cross reactivities of anti-diethy lcarbamazine antibodies with diethylcarbamazine metabolites and iverme ctin were < 0.09%. Using this ELISA, the serum levels of diethylcarbam azine were successfully determined in mongolian jirds (Meriones unguic ulantus) up to 4 h following a single dose of 50 mg kg(-1) of body wei ght. The values of pharmacokinetic parameters of diethylcarbamazine in jirds were determined. (C) 1998 Australian Society for Parasitology. Published by Elsevier Science Ltd.