Toxicology is the study of substances that harm living organisms, either at the cellular or molecular level. From a functional point of view, this discipline can be divided into clinical, environmental, occupational and forensic toxicology. Clinical toxicology focuses on damage caused by acute or chronic exposure to excessive concentrations of a substance.

What is a toxicological study?

A toxicological study is the search of the possible etiological agents that cause a clinical picture of intoxication. Given the great variety of substances with which an individual can be intoxicated, laboratories must work in coordination with the emergency services to determine the appropriate repertoire of tests and the required response times, according to the local reality, regarding the type of population and the most frequent causes of poisoning. For more information you can consult with toxicology consulting services.

To obtain the greatest clinical utility from a toxicological study it is necessary to remember the following points. The emergency services must work in coordination with the laboratories. The clinical suspicion must always be reported to the laboratory in the order requesting tests. Blood and urine samples must be obtained upon admission. The Health Services must know the specialized laboratories where to request advanced toxicological studies.

The two-way analysis

According to the recommendations, toxicology laboratories must provide two levels of analysis. The first level includes the emergency analysis of certain quantitative tests in blood or qualitative tests in urine. The response time required for quantitative blood tests must be equal to or less than 1 h. The second level of drug tests is for patients who remain with compromised conscience or other signs of intoxication. Here a “broad spectrum” analysis is required to search for substances that are not identified at the first level and also to confirm initial screening results. This type of study allows the analysis of samples of blood, urine, gastric contents, vomit and even the suspected drug. Advanced toxicological studies should be referred to specialized centers that have the technology also toxicologists who advise the clinician in requesting tests and support him in their correct interpretation.

What is the validity of an advanced toxicology study?
Since not all substances are detected in a toxicology study, a negative result does not always rule out the possibility of poisoning. Thus, the negative predictive value of an extended toxicological examination is close to 70% and the positive predictive value is around 90%. The negative predictive value may increase to the extent that the diagnostic suspicion is indicated in the medical order, which is the responsibility of the physician ordering the examination.

Source: https://pharmaceuticaldevelopmentgroup.medium.com/what-is-clinical-...