FSM 22: Principles of Toxicology

Not all causes of death are visible to the eye. Some leave no bruise, no fracture, no tear - only biochemical disruption.In this episode, we explore the principles of forensic toxicology: the science of detecting and interpreting drugs, poisons, and chemical agents within the body. Toxicology often transforms uncertainty into clarity - but only when results are interpreted with precision.We examine:* Absorption, distribution, metabolism, and excretion of toxins.* Therapeutic, toxic, and lethal ranges.* Post-mortem redistribution.* Sample collection - blood sites, urine, vitreous humour.* The importance of timing.* Tolerance and chronic use.* Interactions between substances.* The distinction between presence and causation.* Analytical techniques and laboratory processes.A central principle emerges: a toxicology result is not self-explanatory. Concentration must be interpreted within clinical context, medical history, and pathological findings.We also address:* Endogenous versus exogenous substances.* False positives and contamination.* The complexity of mixed drug toxicity.* The medico-legal wording of toxicology findings.Forensic toxicology requires restraint as much as science. Numbers must be translated into meaning without exaggeration.Key Takeaways* Toxicology interpretation requires contextual analysis.* Post-mortem redistribution can alter concentrations.* Therapeutic levels may be fatal in vulnerable individuals.* Mixed drug toxicity is common.* Laboratory accuracy and chain of custody are critical.* Presence does not equal cause.This episode highlights how forensic medicine reads the invisible chemistry of death. This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit drmanaankarray.substack.com/subscribe