Toxicology: Assignment 18
Radhika Tandon
December 5th, 2014

  1. A patient is admitted in an unconscious state with a suspected overdose where the drug taken is unknown. What samples would you expect to receive, what additional information might you require and what would be your approach to identifying the toxic compound?

I would expect to receive urine and blood samples. Additional information that one might require is the medical history of the patient, including current or past diseases, illnesses, and allergies, medications taken by the patient, recent toxic exposures (includes chemicals used in the house/garden), recent travel, recent activities, and anything that might else that might have contributed to rendering the patient unconscious. Questioning friends or family would be helpful, and if necessary, a search of the home.
My approach would be to do a urine drug test using immunoassays for competitive binding, then if the urine screen is positive, run another aliquot of the sample using gas chromatography/mass spectrometry. The reason for the two-test approach is to ensure that the first test is accurate. If nothing is found, I would then test the blood.

  2. When would you use an immunoassay in analytical toxicology. What methods are available, giving examples of suitable chemicals for which the method has been applied, and detailing the drawbacks of their use?

Immunoassays are used to test for the presence of substances in a sample. These methods are fast, sensitive, accurate, and let one determine poisonous concentrations in different biological fluids, for example, blood, urine, saliva, or even hair. Medical laboratories usually use automatic immunoanalysers, like enzyme multiplied immunoassay technique (EMIT), flurescent polarization immunoassay, microparticle enzyme immunoassay, cloned enzyme donor immunoassay, and kinetic interaction of microparticles in solution. These are useful for testing blood or urine for ethanol,...