title: An external quality-control scheme for tricyclic antidepressants.
abstract: Some hospital clinical pharmacology departments operate quality-control schemes to monitor the efficiency of their own and outside pharmacological laboratories in analysing specimens, to maintain or improve quality of performance and to compare the reliability of different methods. The Department of St. Bartholomew's Hospital, London, has been operating a quality-control scheme in which the results from some 18 or more laboratories in analysing the mixed tricyclic-antidepressant content of spiked sera were compared for reliability, six methods being used in all. The measures employed were the overall standard deviation and coefficient of variation, a small coefficient of variation indicating a good quality of performance. Sera contained either amitriptyline and nortriptyline, or imipramine and desipramine. The coefficients of variation were considerably smaller than those reported previously and were greater for external than internal laboratories, while laboratories where tricyclic antidepressants are assayed routinely had a low variation. The skill and experience of the analyst are therefore important. Although there is room for improvement in the scheme, it has already provided valuable objective measures of performance and emphasized the need for a self-critical approach.
mesh_terms: D000639:Amitriptyline / Q000097:blood; D000929:Antidepressive Agents, Tricyclic / Q000097:blood*; D001774:Blood Chemical Analysis / Q000379:methods; D003891:Desipramine / Q000097:blood; D006801:Humans; D007099:Imipramine / Q000097:blood; D007753:Laboratories / Q000592:standards*; D009661:Nortriptyline / Q000097:blood; D011786:Quality Control; D006113:United Kingdom
chemical_list: D000929:Antidepressive Agents, Tricyclic; D000639:Amitriptyline; D009661:Nortriptyline; D007099:Imipramine; D003891:Desipramine