Toxins, antidotes and interferences

Poisoning is a common clinical presentation. The risk assessment of poisoned patients includes measurement of relevant toxin concentrations in the clinical laboratory. All clinical laboratories providing acute clinical services should have measurements of common toxicological analytes available within a reasonable timeframe, since it is essential for both initial clinical decision making and subsequent monitoring of the patients. Analytical interference, from the toxin itself or antidotes used for treatment, may affect results and lead to clinical uncertainty. Laboratories should be aware of potential interferences and have a reference procedure to prevent reporting of misleading results under such circumstances. In this review article we discuss common toxicological analytes relevant to laboratory medicine, especially those with laboratory-based clinical decision points for extracorporeal toxin removal, and antidotes which may cause analytical interference.