General Toxicology

General Toxicology

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Toxicology - Branch of science that deals with poisons with reference to their sources, properties, mode of action, fatal dose, fatal period, symptoms & signs which they produce, method of their detection, treatment & autopsy findings

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Poison  – 

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Drug  – 

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Legally, difference between poison & drug is: Intent with which it is taken

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ACTS The Poison Act (1919):

It deals with: 

- Import of poisonous poisonous substances. substances.

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- License authority for poisonous poisonous substances. substances.

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- Restriction in the sale of such substances.

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Drugs & Cosmetics Act (1940)

It deals with: 

Import, manufacture, distribution & sale of drugs

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Functioning of Central Drug Laboratory

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License authority

The Drugs & Magical Remedies Act 1954 

ensures ethical standards are maintained when drug are advertised by the manufacturer. It prohibits advertisement for:

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Abortion.

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Prevention of conception.

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Maintenance & improvement of capacity to indulge in sexual desire.

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Treatment for menstrual disorders.

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Diagnosis, treatment & cure of venereal diseases.

Drugs & Cosmetic Rules  –  Schedules 

C: Biological & special products.

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E: List of poisonous substance under ayurvedic, siddha & unani system

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F: Vaccines & sera

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G: Hormone preparations

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H: Drugs to be sold only on the prescription of  RMP.

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J: List of diseases like appendicitis, cancer etc for the cure & prevention of which no drug should be advertised.

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L: Antibiotics, antihistamines & chemotherapeutic agents.

The Narcotic Drugs & Psychotropic Substances Act (1985): 

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Amended –  1988 Convention against Illicit Traffic in Narcotic Drugs & Psychotropic Substances 1988 Vienna

Manner of Poisoning Human

Cattle

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Suicidal

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Homicidal

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Accidental

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Oleander

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Stupefying

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Aconite

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Abortifacient

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Arrow Poisons

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Infanticidal

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Misc.

Abrus precatorius

CLASSIFICATION OF POISONS According to S/S  –  •

•

•

Corrosives

Irritants Systemic

Corrosives

Strong Acids  – 

Strong Alkalis

H2SO4, , HCl, HNO3 Carbolic

Hydrates & carbonates of  Na, K, NH3

Metallic Salts Zn Cl2 FeCl2

Irritants  –  a.

b.

Agricultural Inorganic  –  Metallic  –  Pb, Cu, Hg, Ar Non Metallic  –  I2, Br3, PO4 Mechanical  –  hair, powdered glass

c.

Organic  –  Vegetable, Animal

Systemic

CNS

CVS

RS

Misc

CNS

Cerebral

Somniferous Inebriant Deliriant

Spinal Strychnine Gelsemium

Peripheral Curare Conium

b.

CVS  –  Aconite, Tobacco

c.

RS  –  CO, CO2 , H2S

d.

Misc. - Food poisoning

According to site  –  1.

Local

2.

Remote

3.

Local & remote

Factors modifying action of poison 1)

Dose

2)

Form of poison

3)

Route of administration

4)

Condition of body

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Dose:

Quantity Vary Exceptions: a) b)

Idiosyncrasy  Allergy

c)

Tolerance

d)

Synergism & cumulative

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Form of poison

a)

Physical state

b)

Chemical composition

c)

Mechanical composition

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Route of administration

a)

Inhalation > Parenteral > Oral

b)

Stomach contents

c)

Sleep, Narcosis, Trauma

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a)

Condition of body  Age

b)

State of health

c)

Sleep

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Fate of poison

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Local

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 Absorption

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Elimination

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Poisoning: Acute & Chronic

Diagnosis of poisoning  

History

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Papers

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Clinical findings

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Suddenness of onset

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Several persons suffering etc

Poisoning in Living

Poisoning in Dead

- Acute poisoning

- History

- Chronic poisoning

- Papers

- PM Examination: External & Internal - Chemical analysis - Experiment on animals

- Moral & circumferential evidence

 Treatment of poisoning   A)

Removal of unabsorbed poison

B)

Use of ANTIDOTE for absorbed poison

C)

Elimination of absorbed poison

D)

General treatment- Symptomatic

 A) Removal of unabsorbed poison Treatment depends upon Route of Entry e.g. Inhalation- fresh air, artificial respiration Injection- tourniquet, incision & suction Contact- washing Ingestion- emesis, stomach wash

GASTRIC LAVAGE (Syn. Stomach wash ; Stomach pump ; Gastric Irrigation)

DEFINITION :"It is the process of cleaning out the contents of the stomach"

INDICATIONS :1.Mainly useful within 3 hrs. - Salicylates

Uptil 12-18 hrs.

- Phenothiazines. - Tricyclic anti-depressants - Antihistamines.

2. Gastric concretions. 3. Delayed gastric emptying. 4. Sustained release preparations. 5. Morphine / Barbiturates given parentrally :- resecreted by stomach. 6. Hyperthermia

Climatic Drug induced

Iced Solution

APPARATUS Stomach Tube Ewalds Tube Boa’s Tube Round end

Ryle's Tube - Lavacuator  Perforated Lateral openings

Ordinary Rubber Tube

To pump stomach contents (Wooden) 1 end pointed,

(Soft, Non Collapsable)

Hole in middle to pass tube

Length

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1.5 Metres (150 Cms)

Diameter

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1 Cm

( Infant - Children –

10-12 F Catheter )

POSITION OF PATIENT 

Lies on left side / prone. Head hanging over the edge (Stretcher / bed / table) Face down supported by an assistant (mouth at lower level than larynx) Elevated foot end.

PROCEDURE 

Remove any artificial dentures.

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Patient If

Conscious Unconscious

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Lubricate end of tube

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Depress tongue

- Explain procedure. - Obtain informed consent. - put in cuffed (9-10 mm) endo-tracheal tube-balloon the cuff. (prevent aspiration)

PROCEDURE Pass tube (Gradually, Gently, Without force) downwards through

Pharynx

Oesophogus

Stomach Uptil

50 cms mark on tube

ADULTS

25 cms using 10-12 F

INFANT + CHILDREN Catheter / Ryle's tube.

(If No mark on tube :- distance equal to that between bridge of Nose and Xiphisternum)

CHECK PASSAGE OF TUBE INTO STOMACH. Keep free end of tube  just below water surface

Push air into tube auscultate epigastric region

Gurgling sound

air from stomach expelled in 2-3 expirations

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Tube in Stomach 

gag / cough reflex

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air from lungs causes 'bubbling' at each expiration.

nt.

Tube in Air passage 

gag / cough reflex + nt.

X-ray can detect position of tube

TO IRRIGATE Hold the funnel high above patient's head. Pass 1/4th Litre(250 ml) of warm water 35°C. When funnel empty - compress tube below the funnel between finger and thumb. Lower the funnel of tube below level of stomach. Release thumb-finger pressure from rubber tubing.

Siphon Action

Contents of stomach emptied

Preserve Contents. (Chemical Analysis)

CHECK COMPLETION Pour further ½ Litre of solution (as above )

Clear + odourless fluid

No Interaction between Antidote + Poison

PourSmall Quantity of  Cathartic / Antidote

In opium poisoning or it's derivatives

KMno4

Same pink colour as the solution put in

 /Activated Charcoal (1 gm/kg body weight)

No Interaction between Antidote + Poison

If

bleeding

abandon the process.

LAVAGE – WHAT / WHEN MECHANICAL

- Activated Charcoal - Multi dose Activated Charcoal

CHEMICAL

- Water with KMnO4 1:5000 - Common salt in water - Silver nitrate. - Albumen

- Mercuric chloride

- Dialysed Iron

- Arsenic

- Copper Sulphate

- Phosphorous

CONTRAINDICATIONS ABSOLUTE

All corrosive poisoning

RELATIVE (With proper precautions) Comatose patient Pass cuffed

SOFTENS MUCOSA

Except : Carbolic acid THICKENS MUCOSA

endotracheal tube balloon the cuff  Volatile poison Upper alimentary disease e.g.: esophageal varices.

Petroleum Distillates (Kerosene)

Severe hypothermia. Haemorrhagic diastasis. Advanced pregnancy. Recent surgery

COMPLICATIONS Laryngeal spasm. Aspiration - pneumonitis. Perforation of Stomach. Sinus Bradycardia.

B) Antidotes for absorbed poison: -

Def 

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Classification

1)

Mechanical or Physical

2)

Chemical

3)

Physiological or Pharmacological

4)

Universal

Chelating Agents

C) Elimination of absorbed poison 1) Catharsis: a.

Ionic /Saline: Mg citrate, Mg Sulphate, Na sulphate

b.

Saccharides :

Sorbitol

C.I.- Corrosives, diarrhoea, electrolyte imbalance, paralytic ileus 2) Whole bowel irrigation: a.

PEG-ELS

b.

PEG-3350

3) Forced diuresis Indications Forced alkaline diuresis 

Haemodialysis

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Haemoperfusion

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Peritoneal dialysis

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Haemofiltration

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Plasmapheresis

D) General treatment: 

Respiratory depression

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Shock

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Nutrition

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Infection

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General nursing-COMA

Duties of RMP in a case of Suspected Poisoning   A)

Duties towards Patient

B)

Duties towards Relatives

C)

Duties towards State

Duties towards Patient 

Early diagnosis

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Prompt treatment

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Preliminary record

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Homicidal

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Psychotherapy

Duties towards Relatives 

Interview:

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Information about the case

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Information about patient- condition, diagnosis, prognosis

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If food poisoning- inform accordingly