Principles of Toxicology

Important for GPAT

1. PRINCIPLES OF TOXICOLOGY By- Mrs. sonali r. Chintamani ASST. PROF. M. Pharm ( Pharmacology) MBA (INTERNATIONAL BUSINESS MANAGEMENT) PhD (PURSUING) REGISTERED PATENT AGENT

2. Definition of toxicity It is the study of action of overdoses of drugs which may endanger life. Strictly speaking, it is the study of poisons, its effects and treatment for it.

3. Irritant Substances:- 1 . Inorganic – I. Non metallic E.g. – Phosphorus , chlorine, bromine, Iodine . II. Metallic E.g. – Lead, mercury , copper, zinc, arsenic. 2 Organic- i . Animal Origin E.g.:- snake, scorpion, insects. ii. Vegetable Origin E.g.:- Ergot, Castor oil, Aloe. CLASSIFICATION OF POISONOUS SUBSTANCE

4. 3. Mechanical :- E.g. :- Powdered Glass B) Corrosive Substances:- E.g.:- Sulphuric Acid , Carbolic Acid , Oxalic Acid. C) Neurotic :- E.g. :- I. Cerebral Poisons- Opium, Sedatives and Hypnotics . ii. Spinal poisons – Nux -vomica iii. Peripheral Poisons – Alkaloids D) Cardiac :- E.g.:- Digitalis, stropanthus. E) Pulmonary Depressants:- E.g.:- Coal Gas. F) Miscellaneous :- E.g.:- Analgesics, Antipyretics, Stimulants

5. GENERAL TREATMENT OF POISONING:- Five Basic Principles of general treatment of poisoning To remove unabsorbed poison from the body To use antidotes . To excrete absorbed poison . To treat the general symptoms of the victim . To maintain the victims general conditions

6. 1. To remove unabsorbed poison from the body:- Following measures should be taken for the removal of unabsorbed poisons entered by different routes a) poisons entered through nose b) poison entered through contact with skin , eye, or wound. c) poison entered through injection. d) poison entered through mouth. 2. To use antidotes :- These are the substances which neutralize the effect of poison a)Physical antidote:- E.g.- Demulcents Such as fats , oil. b) Chemical antidote:- E.g.- Calcium Oxides. Lime. c) Physiological antidote:- E.g.- Atropine, BAL, EDTA .

7. 3.To excrete absorbed poison.:- The poison has entered the intestine and hence the following measure should be taken to excrete the poison through urine and seat and feces. a) Force diuresis b) use of cathartics c) use of hot packs d) Hemodialysis

8. 4 . To treat the general symptoms of the victim:- 5. To maintain the victims general condition:- To av oid risk of infection the prophylactic antibiotics therapy must be given also the management of hypothermia , intensive supportive treatment and good nursing care is required to maintain the general condition of victim .

9. Antidotes Classification of antidotes: Physiological antidote Chemical antidote Mechanical antidote Universal antidote

10. HEAVY METAL POISONING Arsenic Lead Mercury Copper

11. 1.ARSENIC: SYMPTOMS : Vomitting,blood diarrhoea,jaundice,oliguria, Muscle cramps, pale anxious face, rapid pulse Dilated pupils, coma and death. Fatal-dose : 100-200 mg Treatments: Stomach wash with warm water. Freshly precipitated hydrated ferric oxide as antidote which forms harmless ferric arsenite . I.V. sodium thiosulphate 1 gm in 10 ml sterile water every 4 to 7 hr for 1 st day

12. Lead Symptoms: Vomiting, colic pains in abdomen, headache, loss of sleep, loss of vision, acute hemolytic crisis may occur. Fatal Dose: 0.5 gm Treatment: Stomach wash with 10 % solution of magnesium sulphate followed with plain water.

13. Mercury Symptoms: Metallic taste in mouth ,vomitting,nausea,cold skin, pale face, dilated pupils, shock, loss of memory, anemia. Fatal dose: 400 mg Treatements : Removal of poison by emetics or stomach wash with 5 % solution of sodium formal dehyde sulfoxylate. Diamercaprol therapy for chelation

14. COPPER Symptoms: Metallic taste with excessive salivation, vomitting,hypertension,menstrual disorder. Fatal Dose: 30gm of copper sulphate. Treatments: Removal of poison by emetics or stomach wash with 5 % solution of sodium formal dehyde sulfoxylate. Diamercaprol therapy for chelation. stomach wash with one potassium ferrocyanide.

15. Barbiturate poisoning Symptoms:- Nausea, mental confusion, respiratory depression,dreowsiness,deep sleep,hypotension,skin rash, muscle spasm, cyanotic face, decrease urine formation, death occurs due to respiratory failure. Fatal dose:- 3 to 5 gms. Treatments: Gastric lavage with potassium permanganate. Artificial respiration. To elevate B.P.: 2.5 mg Metarminol,I.V. 5% glucose saline I.V. drip. Forced diuresis. Haemodialysis.

16. Narcotic drugs poisoning Symptoms:- I) Opium :- The symptoms appear in three different stages a)Excitement :- Pleasurable mental excitement with increase in heart rate. b) Sopor :- Headache, giddiness, a sense of weight in limbs, itching c) Narcosis:- Patient enters in deep coma, relaxation of muscles, loss of reflex ,hypotension, pin point pupils . Fatal dose :- 2g or 200mg of morphine

17. Treatments In early stage, stomach wash with tepid water first and then with solution of potassium per magnate . Continue stomach wash till returned water is of pink colour. clear the intestine by enema Antagonist therapy 5 to 10 mg nalorphine,I.V. every 15 minutes till dilation of pupil. For shock 1 liter 5% glucose saline solution.

18. II) Cocaine: Symptoms:- Euphoria, dysphagia , mydriass , dry mouth, heart rate increase, numbness, cyanosis sweating hallucinations ,nasal ,perforations. Fatal dose:- 1 gm Treatments:- Gastric lavage with tannic acid. In local application, wash the skin with water. Artificial respiration. Cardiac stimulant therapy. Medicinal charcoal can also be employed.

19. III) Belladona alkaloids:- Symptoms:- Dry mouth , hot dry skin mydriasis ,vomiting .fever ,delirium , heart rate increased with increase in respiration. Fatal-dose:- 125 mg or 15 to 30 mf hyoscine Treatements :- stomach wash with 5% tannic acid. Neostigmine- 2.5 mg I.V. every 3 hours. Physostigmine 1 to 4mg every 1-2 hr. For excitement – Diazempam 10 mg I.V.

20. Iv) Cannabis:- Symptoms: - Excitement followed by hallucinations, increased muscular movement, mental confusion ,drowsiness,Mydriasis,deep sleep . Fatal dose:- Charas – 2 gm Ganja- 8 gm Bhang – 10 gm per kg body weight. Treatments:- Gastric lavage , saline purgatives I.V. fluids, hypodermic injection of strychnine. Artificial respiration .

21. V ) Pethidine Symptoms :- Dry mouth, mydriasis,flushed face, tachycardia , hyperthermia,drowsiness,coma. Fatal dose:- 2 gm Treatment:- Gastric lavage coramine I.V., symphtomatic treatment.