Position of immunological techniques in screening in clinical toxicology.

There is a continuing increase in the use of immunological techniques in the field of clinical toxicology. This is primarily due to the rapidity by which analytical results are now required, and can be obtained, following the testing of individuals for drug use. There has recently been an increase in the repertoire of assays now available to testing laboratories (e.g., buprenorphine and heroin metabolite assays), with the techniques themselves becoming increasingly more specific for the drugs and/or metabolites being monitored (e.g., methadone metabolite assays). The near patient testing (NPT), or point-of-care testing (POCT), devices are now several generations forward from their inception, with some tests now approaching the sensitivity and specificity of automated laboratory-based methods. This review has been collated from the literature to illustrate some of the possible reasons for the move towards the increasing use of immunological techniques, and to highlight some of the advantages and disadvantages associated with such drug screening methods. In particular, it has been shown that it is important to determine, monitor and review the knowledge and training of the individual using the technique. In addition, quality control and quality assessment are paramount to ensure the validity of any drug testing being performed. It has also been shown that it is vital to maintain and develop the relationships between the staff performing the testing, the laboratory (if the testing is performed using NPT devices), and the clinicians utilising the results obtained from drug testing. Without these links, interpretive errors could arise which could adversely affect the diagnosis and management of patients.