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MBBS DMJ. Dr Pervaiz Zarif. TOXICOLOGY. (I) Clinical Toxicology (II) Forensic Toxicology In our part of world - Certain poisons (easy detection) in west - Pharmaceutical products.(difficult). TOXICOLOGY
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MBBS DMJ Dr Pervaiz Zarif
TOXICOLOGY • (I) Clinical Toxicology • (II) Forensic Toxicology • In our part of world - Certain poisons (easy detection) • in west - Pharmaceutical products.(difficult)
TOXICOLOGY • Toxicology is the science which deals with the poisons in reference to their source, properties, mod of action symptoms which they produce, Lethal dose nature of fatal results, treatment, method of their detection , estimation and autopsy findings.
FORENSIC TOXICOLOGY • deals with the medical and legal aspects of harmful effects of poisonous substances on the human body • see 337- J (Qisas and Diyat) • It is also concerned with their sale & purchase • Poison • It is a substance which when administered , inhaled or ingested is capable of acting deleteriously on the human body. • Almost anything is poison. • No boundary between drug and poison. • IN LAW INTENT IS THE DIFFERENCE
TOXINOLOGY • It is the science which deals with the toxins, products of plants, animal and bacteria fungi which are harmful to human body.
HUMAN POISONING • SUICIDAL POISIONS • KCN,HCN, opium, barbiturates, organ phosphorus poising, oleander etc. • AN IDEAL SUICIDAL POISON • must be cheep • Easy to purchase (available) • Capable of being administered in any food/drink) • Pleasant taste, no repulsive smell. • Lethal dose should be small, • Lethal period-short • Painless
HOMICIDAL POISON • Arsenic, mercury, antimony, aconite, thallium, maddar, strychnine , powdered glass, insulin etc. • AN IDEAL HOMICIDAL POISON • Cheap • Easily Available, • Colorless, odorless, and tasteless, • Must be capable of administered in food/drink.
Symptoms should resemble some disease. • Lethal dose should be small • Fatal period -Long • Should have no antidote for it. • Should not be delectable at autopsy.
STUPEFYING Poison • Alcohol , Dathura, Cannabis Indicia cigarette containing organic material , certain drugs like BDP, Narcotics.
ACCIDENTAL POISONING • Takes place as a result of carelessness. • Quack remedies • Bites by poisonous animals • Food poisoning
CLASSIFICATION OF POISONS • 1- ACCORDING TO MODE OF ACTION (6 GROUPS) • 1- CORROSIVES (Strong acids & Alkalis) • 2- IRRITANTS. • (a) Inorganic (i) non metallic(Phrs. Cl , Br , I ) (ii) Metallic (Arsenic , mercury, Lead copper. etc.) • (b) Organic (i) vegetable(castor oil croton oil Abrus ) (ii) Animal (Cantharides, Snakes , Scorpios, Spiders etc. • (c) Mechanical (powdered glass, Chopped hair , Dried sponge, Diamond dust • 3- NEUROTICS (all alkaloid poisons) • a- Cerebral • (Somniferous( opiodes ) • , Inebriants (Alcohol , anesthetics , sedatives , Hypnotics , Agro Chemicals) • Delirent ( Dhatura , Belladonna hyocymus Cannabis indica )
b- Spinal (Nuxvomicagelsemium) c- Peripheral (Curare conium) 4- CARDIAC (Digitalis , oleander , aconite) 5- ASPHYXIANTS (CO, CO2, Sewer gas, War gases. 6- MISC. (Different pharmacological products (Analgesics, antipyretics, antihistamines , antidepressent etc.
ROUTES OF ADMINSTRATION • (i) Entral ( oral, perrectum) • (ii) Parentral (a) Injection (I.D, I.M, I/V, S/C. ) • (iii) Inhalation • (iv) External Application. • (v) Natural orifices.
ACTION OF POISONS. • (1) LOCAL (direct action) Corrosive and irritants • (2) LOCAL & REMOTE (carbolic acid) • (3) REMOTE (systemic due to absorption (a) specific (b) non specific) (4) GENERAL more then one system is involved and beyond limits like arsenic and mercury
FACTORS MODIFYING THE ACTION OF POISON • 1- Dose • Small dose (Therapeutic results.) • Large dose (Toxic result.) • GENERAL EXCEPTIONS. LIKE • (a) Idiosyncrasy (inherited intolerance) • (b) Allergic reaction, (Hypersensitivity). • (c) Habit (tolerance like Alcohol) • (d) Synergism • (e) Elimination from body.(cumulative poisons)
2- FORM OF POISON • A- PHYSICAL STATE (gas, Liquid and solid) coated pills take more time. • B- CHEMICAL COMBINATION ( inert like strychnine with tannic acid , led carbonate + copper arsenate ) • C- MECHANICAL COMBINATION (Acid diluted with water) 3- METHOD OF ADMINSTRATION. (A)- INHALED (rapid) (B) Intravenous, (I/V, S/C, I/M) 4- CONDITION OF THE BODY • 1. Age • 2. State of health 3. sleep & intoxication
DIAGNOSIS OF A CASE OF POISONING (1) IN LIVING • ACUTE POISONING • - symptoms suddenly appear • - Person is in good health previously • -symptoms do not conform to an ordinary illness • - Other persons who have taken same item effect in same manner. • -Symptom rapidly increase in severity. • -Followed by death or recovery • -Poison can be detected ingredients of food medicine, fluid, vomit, gastric lavage Blood, urine and stools.
CHRONIC POISONING • Symptoms develop insidiously and gradually • - There is exacerbation of symptoms after intake of suspected food, medicine or fluid. • - There is remission or complete disappearance of symptoms after removal of patient from the source. poison can be detected in routine samples and things being used by the patient • main symptoms being malaise generalized weakness, deterioration of health , repeated attacks of undiagnosed G.I irrigation. • Usually Homicidal intent
POISIONING IN DEAD • Evidence of poisoning depends on • Postmortem examination • Chemical analysis • Experiments on suitable animals • Moral and circumstantial evidence • NOTE: poison retard puturifactions
P.M. EXAMINATION • Same procedure • Smell from clothes, body • Froth from nose and mouth • Stains on lips chin etc, • Colour of skin and and postmortem lividity • Marks of injections • Condition of natural orifices • G.I system should be especially watched for hyperemia, softening, ulceration, perforation
CHEMICAL ANALYSIS: • Detection of poison in paranchyma of organs (proof) • Finding of poison is food, drinks is taken as corroborative. • EXPERIMENTS ON ANIMALS: • Dathuracat,s eyes • MORAL & CIRCUMSTANTIAL EVIDENCE • Clues regarding recent purchases • Behavior of the victim/ suspected • Any suicidal note • H/O fight, financial problems/love affairs • Disposal of dead body in haste.
DUTIES OF A DOCTOR IN CASE OF POISONING • Must record preliminary particulars as name, age, sex, occupation, address, date and time, brought by whom, history, dying declaration. • Doctors duty is to treat the patient. • If in private practice- no need to report but if summoned by police/ count must divulge the case • If poisoning is accidental (hotel/ water tank) must notify it • If doctor is convinced about homicide must inform police • If in is Govt. setup must inform police about all the cases coming to hospital • Record keeping should be meticulous. • Must collect the samples like stomach wash. Vomiting, urine, blood for analysis.
Any suspicious article like utensils, bottles & containers, food or drink near the person. • Clothes and bed sheets of victim. If soiled by vomitus etc. • If the patient is serious arrangement for dying declaration • IF THE PATIENT DIES THEN • Must issue death certificate after informing the police and • Any opinion about nature of poison should be given after the report from chemical examiner • If doctor is performing autopsy viscera should be preserved and sent for C/E
TREATMENT OF POISONING: • If poison is known then treat specific poison • if not known on general lines of management • Main aim to stay the patient alive by supporting respiration and circulation • Assisted by getting rid of poison by metabolism, excretion • Use of antidote by getting rid of poison
OBJECTIVES: • Removal of unabsorbed poison • Use of antidote • Elimination of unabsorbed poison • Treatment of general symptoms • Maintenance of patient's general condition
REMOVAL OF UNABSORBED POISON: • Depending upon route of entry • INHALEED POISON: (CO,H2,S) • Remove from sources to fresh air • Artificial respiration • Keep airway patent (posture drainage) b. INJECTED POISON: (hypnotics, insulin, sedatives) • A tight tourniquet proximal to point of injection • Must be relaxed for one min after 10 min • Wound may be excised and poison removed
c. CONTACT POISON: • Spilled or sprayed on skin, eyes or wound • Best way is to wash it out with water • Neutralize it by an antidote.
d. INGESTED POISIONS • Remove from stomach as much as possible by Vomiting, and stomach wash. • If patient is conscious and cooperative and vomiting is not contra indicated. • ( Strychnine , corrosive, petroleum, distillates, coma) • ( cardio-resp. diseases, Advanced pregnancy. • Induce it by tickling the fauces and by use of Emetics.
HOUSE HOLD EMETICS • Warm water. • Mustard powder ( Tea spoon = 15 gm) • Two table spoons of NaCl + 200ml tepid water) • IPECAC 1- 2 gms or its syp 30ml.( may repeat • Once) • Apo morphine 6 mg s/c followed by nalaxone Hcl 5-10 mg i.m/i.v causes vomiting in 3-5 min. • Facilitate gastric lavage by removing contents • Produce gastric/intestine reflux (Tab)
GASTRIC LAVAGE • If not contra indicated-may be life saving but should be undertaken within 6 hours. • Contraindicated in corrosives ( exception in carbolic acid. • Certain measures should be taken such as • Strychnine poisoning ( control fits ) • Kerosene poisoning ( airway should be sealed ) • Hypothermia ( Body temp should be maintained.
PROCEDURE • in prone or semi prone position • Head should be down. • Flexible rubber tube about 12.7mm diameter • And 1½ met . in length. • Lips to cardiac end 45 cm. • Air should be injected (sound heard) • ¼ litters of water (35 C ) • First – funnel is up them down. • Subsequent washings e ½ liters of water • 1st washing is preserved. • Appropriate antidote should be used. • Color of fluid is noted till it return uncharged. • Last fluid should be kept in stomach.
SOLUTION USED • Mg2So4 or Na2So4 ( purging) • NaHCO3 ( Aspirin poisoning ) • Activated charcoal (adsorbs Alkaloids) • Liquid paraffin (demulcent) • KMnO4 – (oxidizing agent) IN CHILDREN • 8 – 12 fr • 25 CM • Stomach wash with 50ml glass syringe
ANTIDOTS • DEF:- • Remedies which counteract or neutralize the effects of poisons without causing appreciable harm to body . • IT IS USED WHEN • a-A poison may not have been completely removed • b- The poison is already absorbed. • The poison has been administrated by routes • other than ingestions.
CLASSIFICATION • Mechanical or physical. • Chemical. • Physiological or Pharmacological • Universal.
MECHANICAL OR PHYSICAL • Impede the absorption of poison such as demulcents, bulky food and activated charcoal • Demulcents: fat, oil, milk, egg albumin • (used in corrosive, irritants) fatty substance should not be used in fat soluble poisons (phosphorus,organo phosphorus) • Bulky food; banana, for glass • Activated charcoal (alkaloidal poison, strychnine) • Dose is 30-60gm in children • 60-100gm in adults • 5-10 % the amount of poison ingested
CHEMICAL • By direct chemical reaction • By oxidizing-to non toxic compound as a. Dilute acetic acid _ alkalis b. Dilute alkalis as milk of magnesia _ acids (bicarbonates are not used _ rupture of stomach) c. tannin (strong tea)_ alkalis, glycosides, metals d. KMnO4 oxdieses (barbiturates, phosphorus, cyanide),(1:1000)-dilution, (100-150ml left in stomach)
PHYSIOLOGICAL OR PHARMACOLOGICAL • Produce effects which are opposite to that effects of the poison as a. Atropine for pilocarpine • Diazepam for strychnine • Naloxone for morphine • Atropine and oximes for organophosphorus • N-acctylcystine for paracetamol • Mazicon for Benzodiazpines • (however antagonism is always not complete and undesirable side effects may be there)
CHELATING AGENT • Firm non ionized cyclic complex • BAL (British antilewsite),(dimercaprol) 3 mg/kg 4Hr contra indicated in liver damage For next two days 6mg 3days • EDTA(Ethylene Diamine Tetra acetate) arsenic 1gmxBDx5days S/IV uniform(Renal damage-contra indicated) • VERSENATE (Arsenic) • Pancillamine (Hg,lead,copper,) orally,30mg/kg-(2gm) • Desfuroxamine (iron) • UNIVERSAL ANTIDOTE • Powdered charcoal-2parts- alkaloids • Milk of magnesia -1 part - acids • Tannic acid-1 part- alkaloid,glucoside metal • Dose: (one table spoon full in water 200 ml)
ELIMINATION OF ABSORBED POISON • Excretion through urine (excessive water in take, alkalinizations of urine) • Petroleum distillates • Haemodialysis • Exchange transfusion Rx OF GENERAL SYMPTOMS • Apply it when indicated • Morphine for pain, O2 for resp. support • Cardiac stimulants for failing heart • Saline infusion for dehydration • Administration of glucose ---> liver demage • Electrolytes imbalance by K-Na etc
MAINTAINENCE OF Pt. GENERAL CONDITION • Warm and comfortable • Avoid risk of infection • Administration of antibiotics • Psychiatric counseling