Radioreceptor assay of neuroleptics in refractory chronic schizophrenic patients.

Radioreceptor assay, a promising new tool for studying serum levels of neuroleptics and their biologically active metabolites, was used to elucidate the role of neuroleptic plasma levels in 24 chronic schizophrenic patients with a poor clinical response to standard treatment. Most of these 24 patients attained serum levels reportedly associated with improvement in more acute patients, suggesting that their lack of response was not due to relative absence of drug in serum. Alternative reasons for lack of response despite adequate plasma levels are discussed.