[Thin-layer chromatographic determination of plasma levels of tricyclic psychopharmacological drugs: first results on their relationship to the clinical activity of neuroleptics (author's transl)].

Plasma levels of perazine, clozapine, amitriptyline and imipramine and of their demethylated metabolites can be measured in patients receiving therapeutic doses by UV reflectance photometry of thin-layer chromatograms of plasma extracts, Large inter-individual variations were observed in unselected psychiatric patients treated with comparable doses. An investigation into the relationship between plasma levels and therapeutc effect in acutely schizophrenic patients was carried out for perazine and clozapine. With perazine, a group of patients exhibiting an unsatisfactory response had a tendency to show lower plasma levels than a group with a good response; in some patients of the former group, increase of the dose with concomitant increase of the plasma level led to a satisfactory therapeutic effect. In patients treated with clozapine, such a relationship could not be demonstrated.