[Immunologic studies of benzodiazepine--the effect of structural characteristics on cross-reactivity].

The manufacturers' descriptions for immunoassays for the detection of benzodiazepines in urine suggest that all therapeutically used benzodiazepines are detected equally. It is unlikely that the different molecular structures do not influence the results of pertinent measurements. Therefore, the cross-reactivity of 35 benzodiazepines and benzodiazepine-metabolites was determined with the TDx-system. As compared to nordiazepam all compounds--except diazepam--had a reduced cross-reactivity. In order to get a TDx result equal to or exceeding 200 ng/ml nordiazepam-equivalents, high benzodiazepine concentrations in urine are required in some cases. These high concentrations are not obtained in the therapeutic range of application. These considerations can be applied to other immunoassays like RIA and EMIT.