The use of radioreceptor assays for the determination of benzodiazepines in biological samples: a review.

Benzodiazepines are the most widely prescribed class of psychotropes. The demonstration of specific, high affinity binding sites for benzodiazepines in mammalian brain has provided a basis for a radioreceptor assay (RRA) of these compounds in biological samples (fluids or tissues). The RRA permits the simultaneous measurement of the benzodiazepine molecules that bind to the receptor, providing a total estimate of all pharmacologically active forms of the drug, which is useful in drug monitoring and in the intensive care of patients. After a complete description of the methodological aspects of this technique, the results obtained in therapeutic monitoring and in toxicological analysis are reviewed, and the advantages and disadvantages of this method are examined.