Forensic Toxicology PDF

Forensic Toxicology 1 03/31/24  Toxicology: from the Greek words toxicos (arrow) and logos (study). It is defned as the study of the adverse efects of chemicals on living organisms. It includes the study of symptoms, mechanisms, treatment,...

Forensic Toxicology 1 03/31/24  Toxicology: from the Greek words toxicos (arrow) and logos (study). It is defned as the study of the adverse efects of chemicals on living organisms. It includes the study of symptoms, mechanisms, treatment, and detection of poisoning, especially the poisoning of people. 2 03/31/24  Forensic Toxicology Deals with the medicolegal aspects of the harmful efects of the chemicals on the human beings. It combines the basics of toxicological principles with analytical chemistry. 3 03/31/24  The Roman physician Paracelsus is regarded as the father of toxicology. He is credited with the classic toxicology sounbite “ All things are poisons and nothing is without poison ; only the dose makes a thing a poison. Mathieu Orfla is considered as the father of modern toxicology. 4 03/31/24  Toxin Any substance exerting a harmful efect on a living organism  Forms? 1. Gaseous (e.g. CO, cyanide) 2. Liquids (e.g. household cleaning supplies, alcohol) 3. Solid (solid Drugs) 5 03/31/24  CLASSIFICATION OF POISONS:- NATURE: Solid, liquid and gaseous. SITE OF ACTION: 1.LOCAL{Inorganic corrosives}. 2.Remote {Alkaloids and most therapeutics} 3.Local and remote{Metals and organic corrosives. 6 03/31/24  TARGET ORGAN: 1.CNS stimulants: amphetamines and cocaine.CNS depressants: hypnotics, sedatives, narcotics, alcohol, anesthetics. 2.GIT:Metals and corrosives. 3.Kidney:mercury and cadmium. 4 Liver: Paracetamol and Iron. 7 03/31/24  Classifcations 5.CVS: Digitalis. 6. Lungs: Metal fumes 8 03/31/24  FACTORS MODIFING TOXIC EFFECTS:- 1.POISON:- a.Quantity: increase dose – increase severity of symptoms. b.Quality : gases are rapidly absorbed>liquids>solids {powder>lumps}. 9 03/31/24  c. Route of administration: I.V Inhalation. I.M. Skin{s.c} Mucous membrane. Skin {intradermal} 10 03/31/24  d. cumulation: Rate of intake>rate of elimination e.g. digitalis. e. Chemical interaction: Addition(1+1=2) e.g. Aspirin+paracetamol Synergism(1+1=3) e.g. Alcohol+barbiturate. 11 03/31/24  Antagonism:e.g.BAL+Lead. 2.Patient factors: a.GIT: Ph of the stomach{acidic}increase Hcl increase Aspirin toxicity. Amount of food:Empty stomach increase toxicity. 12 03/31/24  Type of food: fatty mealincrease absorption of fat soluble poisons. b. Age: toxic efects are severe in extremes of age. c. Health: increase efect of poisons in: Liver diseasesdecrease metabolism. 13 03/31/24  Kidney diseasedecrease excretion. Heart diseasedecrease metabolism and excretion by impairing hepatic and renal circulation. d. Toxicogenetics {idiosyncrasy} Abnormal response to drugs. Hereditary basis e.g.favism and sulpho namide in G6PD DefciencyHyltic anemia 14 03/31/24  e. Hypersensivity = allergy Exaggerated response to drugs e.g. aspirin or penicillin. Ag- Ab reaction. f.Tolerance :addicts can tolerate large doses of drugs as opium, barbiturates and amphetamine than normal person without serious efects. 15 03/31/24  ThnQ 16 03/31/24