The use of postmortem forensic toxicology to day. An alert for the pathologist

Tricyclic antidepressant drugs concentrations in blood and other biological fluids and tissues, do not remain constant in the body in the interval between death and the collection of samples. Blood drug concentrations change significantly during the postmortem period. Because amitriptyline and the other tricyclic antidepressants are highly tissue bound, tissue release in the postmortem period gives rise to elevated blood levels. Postmortem Drug diffusion from solid organs into the blood is mainly a matter of passive diffusion as described by Fick's first law of diffusion, which states that the rate of diffusion is proportional to the concentration gradient across the diffusion barrier. This postmortem redistribution can result in increase in postmortem blood amitriptyline concentrations to roughly 2–8 times the perimortem levels. Unless postmortem concentration changes, several factors, can render blood and tissue samples useless for the determination of antidepressant here drug concentrations. The data of the two cases presented here illustrates the need for a thorough examination of death scene, reviewing the deceased's history and detailed examination of the body. The potential of false determination of the cause and manner of death in cases with tricyclic antidepressants is an existing factor while considering only the postmortem concentrations of the drugs in the blood and tissues.