General Principles of Toxicology

Laws related to poisons, Medicolegal duties of a doctor in poisoning cases, Classification, Diagnosis, Lab analysis and Treatment of Poisons

1. TOXICOLOGY 1 Dr. Divya Reddy Assistant Professor Department of Forensic Medicine and Toxicology, RVMIMS

2. Definitions History Epidemiology Law of poisons Duties of a Medical Practitioner Nature of poisoning Classification of poisons Types of poisoning Diagnosis of poisoning Laboratory analysis Management SUMMARY 2

3. Toxicology is the science dealing with properties, toxicity, fatal dose, detection and estimation of, interpretation of the results of toxicological analysis and treatment of poisons. Forensic toxicology deals with the medical and legal aspects of the harmful effects of chemicals on human beings. Poison is a substance (solid, liquid or gaseous) which if introduced in the living body or brought into contact with any part there of will produce ill-health or death, by its constitutional or local effects or both. DEFINITIONS 3

4. 1. The Drugs And Cosmetics Act 1940 2. The Drugs And Cosmetic Rules 1945 3. The Pharmacy Act 1948 4. The Drugs Control Act 1950 5. The Drugs And Magic Remedies Act 1954 6. The Narcotic Drugs And Psychotropic Substances Act 1985 LAW OF POISONS 4

5. Regulates the function of Central Drug Laboratory, appointment of licensing authorities and manufacture, distribution and sale of drugs THE DRUGS AND COSMETIC RULES 5

6. Drugs to be sold only on prescription of registered medical practitioner . Eg: Barbiturates, antibiotics, amphetamines, etc. SCHEDULE H DRUG 6

7. A medical facility that provides free, immediate, expert treatment advice and assistance over the telephone in case of exposure to poisons 7

8. Medical Duty: Diagnose and treat Legal Duty: Information to Police – Must report all MLC to the police. Sec 39 CrPC – Public to give information of certain offences Sec 176 IPC – Omission to give information Sec 201 IPC – Causing d isappearance of evidence Sec 202 IPC - Intentional omission to give information of offence Examination of Scene of Crime At the hospital – Preservation of body fluids, clothes and send for analysis Arrange for Dying Declaration In case of food poisoning, Notify public health authorities In case of death – no death certificate is issued DUTIES OF A MEDICAL PRACTITIONER 8

9. Homicide: Colorless, odorless, tasteless Easily available Cheap Highly toxic No Antidote available No Postmortem changes No test available to detect it Symptoms should resemble a natural disease Symptoms should appear late after administration to avoid suspicion Eg for deal homicidal poison: aconite, thallium, arsenic, digitalis NATURE OF POISONING 9

10. Suicide : Produce an easy/painless death( eg : opium, barbiturates) Easily available(OP, aluminum phosphide) Easily taken in food or drink Highly toxic Cheap, color, odor or taste are not important Eg for ideal suicidal Poison: opium, barbiturates, OP. Para suicide : (para, “near” or “resembling”) Refers to suicide attempts or gestures and self harm where there is no actual intention to die NATURE OF POISONING 10

11. Accidental: Ingestion in mistake for harmless substance(acid ingested as it appears like water) Inhalation of vapors through accident(MIC vapor inhaled in B hopal gas tragedy) Incorrect preparation of medicines that contain a poison Abortion : E.g: cantharides, calotropis, arsenic, aconite NATURE OF POISONING 11

12. Aphrodisiacs : Substance that increases sexual desire. E.g: arsenic, cannabis, cantharides, cocaine, opium, strychnine Arrow poisons : Tip of arrows for hunting and to kill enemies Ideal arrow poison must be poisonous parenterally and safe orally E.g: Plant based: abrus precatorius, aconite, calotropis, croton oil, curare, strychnine Animal based: Batrachotoxin(BTX) NATURE OF POISONING 12

13. H . Cattle poisoning : To obtain hides E.g: abrus, aconite, oleander, strychnine, calotropis, nitrates Stupefying : To stupefy travelers for robbery or women for sexual assault. E.g: cannabis, chloral hydrate, datura NATURE OF POISONING 13

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16. Hematological system: anticoagulants(warfarin) Immune system: immunosuppressive agents Hepatotoxic agents: alcohol, paracetamol, phosphorus Nephrotoxic agents: cantharides, cephalosporins, sulfonamides Pulmonary toxic agents: chlorine, phosgene, silica CNS: Organophosphates, Strychnine CVS: digitalis, oleander Dermatological: arsenic, camphor Reproductive system: alkylating agents Endocrine system: thiouracil, calcitonin ACCORDING TO AFFECTED TARGET ORGAN 16

17. Depends upon the amount of poison taken, the time period over which poison taken Hyperacute - produced by a single massive dose. Death occurs very rapidly. No time for signs and symptoms. Acute - excessive single dose, but less than that used in hyperacute poisoning. Subacute - gradually over some time. Doses taken are small and over a short period of time. Chronic - very minute doses taken over a long period of time. E.g: plumbism Acute on chronic- the victim is suffering from chronic poisoning on top of it acute poisoning occurs. E.g: chronic drug abuse TYPES OF POISONING 17

18. Sudden appearance of symptoms- GIT : abdominal colic and pain, vomiting, hematemesis Hepatic : jaundice CNS : paralysis, tremors, convulsions, seizure, coma Renal : oliguria with proteinuria and hematuria Natural diseases Any association with food Multiple victims Causes of acute abdomen: heavy metals, mushroom poisoning Vomiting and diarrhea: OP, irritants Constipation: botulism, iron, lead, lithium Tremors: caffeine, carbon monoxide, alcohol Convulsions and seizures: OP, DDT, ethanol withdrawal, lead, lithium DIAGNOSIS OF POISONING 18

19. Clinical signs : BP: Hypotension : cyanide, clonidine, antidepressants, heroin Hypertension : ethanol, OP, nicotine, atropine, LSD, nicotine Heart rate: Bradycardia : clonidine, cholinergics, cyanide, opioids, OP, digitalis Tachycardia : alcohol, cocaine, cyanide Cardiac arrhythmias : alcohol, caffeine, tobacco DIAGNOSIS OF POISONING 19

20. Ocular signs: Miosis : alcoholic coma, nicotine, caffeine, carbamates Mydriasis : alcohol, ergot, CO, cocaine, Datura, viper bite Ears (buzzing): camphor, ergot, salicylates, quinine Pulmonary: Bradypnea : cyanide, narcotics, ethyl alcohol Tachypnea : cyanide, carbon monoxide, methanol, paracetamol DIAGNOSIS OF POISONING 20

21. CNS signs : Ataxia : alcohol, narcotics Coma : CO, lead, OP, sedative Urine: Yellow/brown : myoglobin, quinine, cresol Red/brown : bilirubin, hemoglobin, myoglobin Blue/green : bile, biliverdin Black : blood DIAGNOSIS OF POISONING 21

22. In the dead: PM findings : External : Stains : clothes, corners, or other surface of the body Natural orifices : presence of poisonous material Skin : injection marks, jaundice Marks of violence : abrasions, bruises, wounds Internal : Odour DIAGNOSIS OF POISONING 22

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24. Mouth, throat and associated structures : erosions, ulcerations, evidence of inflammation Esophagus : softening and desquamation of mucosa(alkalis), ulceration(corrosives), perforation(corrosive ingestions) Duodenum : perforation(alkalis) DIAGNOSIS OF POISONING 24

25. Respiratory tract : edema of glottis (corrosives), edema of lungs(gaseous poisons) Stomach : Hyperemia of mucus membranes caused by irritants at cardiac end and greater curvature Softening: corrosives Ulcers: Magenstrasse Perforation DIAGNOSIS OF POISONING 25

26. Color changes in the mucus membrane : Black, charred- H2SO4,HCl, oxalic acid Blue - amytal, copper sulfate Brown - cresol Cherry red - CO Congested- phosphorus White - arsenic Yellow - nitric acid DIAGNOSIS OF POISONING 26

27. Stomach and contents Upper 30 cms small intestine and contents Liver(200-300gm) Kidney – half of each Blood- 30ml Urine- 30ml Food or medicine Sample of preservative used Individual organs in specific poisonings LABORATORY ANALYSIS 27

28. Saturated solution of common salt : MC used Contra-indicated in : corrosive poisoning, aconite, plant poisons and heavy metal poisoning. Rectified spirit : Contra-indicated in : kerosene, phenol, alcohol, phosphorous, paraldehyde, acetic acid poisoning. Sodium Fluoride : for blood, CSF, vitreous humor and urine. PRESERVATIVES 28

29. Immediate resuscitative measures Removal of unabsorbed poison from the body Removal of absorbed poison from the body Administration of antidotes Symptomatic treatment Adequate follow up MANAGEMENT 29

30. A- AIRWAY = endotracheal intubation, tracheostomy B- BREATHING = adequate tidal volume, ABG C- CIRCULATION = pulses(presence or absence), IVF, CPR D- DEPRESSION OF CNS = GCS E- EVALUATION OF PATIENT = breath sounds, heart sounds, enlarged liver(hepatotoxic poisons), lack of bowel sounds – anticholinergic poisons, ECG, elimination of poison D also stand for decontamination (ocular- copious saline lavage, skin- copious water, then soap and water, GIT- emesis, lavage), dextrose, dialysis, disability evaluation, drugs IMMEDIATE RESUSCITATIVE MEASURES 30

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32. INHALED POISONS- (CO, H2S, Cl2) Fresh air Air passages Endotracheal intubation Artificial respiration and O2 Diuretics REMOVAL OF UNABSORBED POISON FROM THE BODY 32

33. INJECTED POISONS Reassurance ABCDE Shock Allergies Remove sting Local vasoconstriction REMOVAL OF UNABSORBED POISON FROM THE BODY 33

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35. CONTACT POISONS- Eye Skin INGESTED POISONS- Emesis- substance that induces vomiting when administered orally or by injection. (IPECAC) Gastric lavage Whole bowel irrigation- which are not absorbed by activated charcoal REMOVAL OF UNABSORBED POISON FROM THE BODY 35

36. 36 GASTRIC LAVAGE

37. 1) Identify the specimen Gastric lavage tube/ ewalds tube 2) Draw and label its parts 3) Mention its contraindications Corrosive poisoning except carbolic acid, oxalic, acetic acids Convulsant poisoning - strychnine Comatose patients Volatile poisons like kerosene and petrol 37 F unnel Rubber tube Wooden mouth gag Lateral opening 100 cm mark Suction bulb

38. 1) Identify the specimen Ryle's tube/Nasogastric tube 2) Draw and label its parts 1 st mark - 40cm – cardia of stomach 2 nd mark - 50cm – body of stomach 3 rd mark - 55cm – pylorus of stomach 4 th mark - 65cm – duodenum 3) Mention its indications For stomach wash in poisoning Aspiration of gastric contents for analysis For nasogastric feeding and medications 4) Mention its contraindications Acid poisoning meningitis 38 Lateral openings

39. Diaphoretics- drugs that increase sweating(blankets, antipyretics, hot beverages like tea, coffee) Enhanced renal excretion Urine alkalization- in barbiturates, salicylates poisoning Urine acidification/ forced acidic diuresis- in cocaine, strychnine Hemodialysis - in barbiturates, boric acid, alcohols Peritoneal dialysis- alcohol, barbiturates, lithium Hemoperfusion - large volumes of patient’s blood are passed over an adsorbent substance to remove toxic substances. In Barbiturates, paraquat , CCl4 poisoning REMOVAL OF ABSORBED POISON FROM THE BODY 39

40. Based on mechanism of action : Mechanical or physical antidotes Chemical antidotes Chelating agents Serological antidotes Physiological or pharmacological antidotes CLASSIFICATION OF ANTIDOTES 40

41. Work mechanically on poisons within GIT. Adsorbents: which adsorb poisons on to their surface eg: activated charcoal Demulcents : prevent their absorption by making a protective coating on stomach wall. eg: milk, starch, egg white, milk of magnesia Diluents: dilute the poison rendering them ineffective eg: plain water, bulky food MECHANICAL OR PHYSICAL ANTIDOTES 41

42. 1) Identify the specimen Activated charcoal 2) Write its uses mechanical/physical antidote for following poisoning: Barbiturates, BZD, antidepressants, antiepileptics, theophylline, tetracycline, beta blockers 3) Mention its contraindications Intestinal obstruction GI Perforation Haemorrhage Pesticides Aspiration risk 42

43. Neutralize the poisons chemically within the GIT. ACIDS : neutralize alkalis eg: canned fruit juice, lemon juice, vinegar ALKALIS: neutralize acids. eg: alkaline hydroxides(calcium, magnesium) ALBUMEN : mercuric chloride and copper poisoning IODINE : for lead, mercury, silver poisoning KMnO4: for atropine, opium, strychnine, phosphorous poisoning TANNIC ACID : precipitates metals, nicotine, strychnine, cocaine Universal antidote: 2 parts activated charcoal; 1 part MgSO4; 1 part tannic acid CHEMICAL ANTIDOTES 43

44. Chemicals that form soluble, complex molecules with metal ions, inactivating them so that they cannot react with other elements. BAL( British anti- Lewsite, Dimercaprol) Indications: Mercury, Arsenic, Lead(MAL) BAL analogues: DMSA (2,3 DiMercaptoSuccinic acid)- MA L DMPS (2,3 DiMercapto-1- Propane Sulfonic Acid)- MAL EDTA- MA L, cadmium, cobalt, copper, manganese D- Penicillamine -copper, zinc, mercury, lead, etc. Desferrioxamine - acute iron poisoning CHELATING AGENTS 44

45. Antisnake venom Antispider venom Fab therapy for digitalis SEROLOGICAL ANTIDOTES 45

46. Work at the target cell by producing pharmacological effects exactly opposite to those produced by poison. Examples: Amyl nitrite- cyanide Barbiturates- strychnine Physostigmine - atropine PHYSIOLOGICAL OR PHARMACOLOGICAL ANTIDOTES 46

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48. Treat Anxiety and agitation Allergic reactions Cardiac arrhythmias Cerebral edema CNS depression: Coma Cocktail- DNB(Dextrose, Naloxone, thiamine(B1) Convulsions Vomiting ADJUNCTIVE THERAPIES AND SUPPORTIVE TREATMENT 48

49. 49 THANK YOU