CTEH®’s pharmacology & toxicology professionals have extensive experience assessing the human toxicity of drugs and chemicals, and drug interactions and adverse reactions. CTEH® provides additional experience in pharmacokinetic analysis. Levels of drugs or chemicals in blood and/or urine are frequently key pieces of information in accidents, worker exposure issues, and in exposures to environmental chemicals. Proper evaluation and interpretation of these levels is essential. Multiple drugs or chemicals (including alcohol) are commonly found in blood samples taken from individuals, particularly after involvement in an accident. These compounds often have additive and supra-additive (synergistic) effects on the body. To evaluate these and other complex pharmacological situations, we use scientifically sound pharmacokinetic modeling of compounds at earlier points in time (at, for example, the time of an accident).