This post is also available in: English Slovenščina (Slovenian)

Unexpected results of laboratory tests may be due to various factors. These include drug effects, which may be either biological, or due to analytical interferences. The more com­mon biological effects include direct and indirect effect produced by drugs in vivo; in conse­quence laboratory tests yield unexpected, yet correct results. By contrast, the results of tests influenced by the interference of drugs with ana­lytical tehniques are not accurate. International guidelines for the evaluation of drug effects have been formulated, allowing for the compa­rability of data of different studies. The devel­opment of drug effects databases has facilitated the access to the rapidly increasing body of data, which need to be evaluated for their clin­ical and laboratory significance.