1. Organophosphate poisoning

2. Objectives Mode of toxicity Variability of toxicity Toxicokinetic
Toxicodynamic
Clinical picture
Treatment & prevention

3. Organophosphate Poisoning

4. Herbicides and Fungicides
Insecticide and pesticides
Organophosphates and carbamates
Herbicides and Fungicides
Rodenticide

5. Mode of toxicity Accidental: After
Eating contaminated food or insecticides used in
gardens cause accidental poisoning in children.
Transdermal : Lice control by special products (malathion).
Occupational: exposure in farm workers during application.
Suicidal: poisoning by (parathion).
Homicidal poisoning: rare.

6. Variability of toxicity
High toxic  agricultural insecticides  parathion
Intermediate  animal insecticides
Low toxic  household use  malathion
Ex: Fatal oral dose:
Parathion g/ 70 kg
Malathion g/ 70 kg

7. Toxicokinetic Absorption Through skin, GIT, Resp. Distribution
Most are water soluble , few lipid soluble
Metabolism
Some metabolites are more toxic (maloxone - paroxone)
Excretion
In urine

8. Toxicodynamic Acetylcholine
Acetylcholine is the most important chemical transmitter at synaptic junctions
Acetylcholine
So inhibition of acetylcholinestrase increases Ach at nerve endings (OP’s effect).
Acetylcholinestrase
Acetic acid + choline
Hydrolysis

9. Acetylcholine at synaptic junctions

11. Clinical Picture + Death Acute Cholinergic: Peripheral Muscarinic
Peripheral Nicotinic
Central
Respiratory failure
+ Death
Late complication: O.Ph. Induce intermediate or type 2
organophosphate syndrome and delayed neuropathy

12. D U M B E L S Muscarinic Effects D iarrhoea U rination M iosis
B radycardia, Bronchorrhoea, Bronchospasm
E mesis
L acrimation
S alivation

13. M A T C H Nicotinic Effects M uscle weakness and paralysis
A drenal medulla activity increase
T achycardia
C ramps of skeletal muscles.
H ypertension.

14. 2C 2D SHM CNS effects C onfusion C oma D isorientation
D epression : Respiratory & circulatory centers
H eadache
M alaise
S eizures

16. Management Resuscitation Atropinisation of symptomatic patients
The priorities in management are:
Resuscitation
Atropinisation of symptomatic patients
Decontamination

17. 1- Immediate supportive measures
Patent airway + oxygenation
Atropine until secretions dry
Frequent suction
Endotrachial intubation & mechanical ventilation in severe cases
Cardiac monitoring

18. 2- Decontamination Skin decontamination: - Remove clothes
- Wash skin with water and soap then alcohol then soap and water.
GIT decontamination:
- Activated charcoal.
- Emesis & gastric lavage are contraindicated

19. 3- Antidotes Atropine : Initial atropine dose (IV or IM)
1-2mg (adult)
0.05mg/kg (children)
Dose can repeated every sec till Clear chest on auscultation or ATROPINISATION..
Pralidoxime (2-PAM chloride) before aging
Dose 1-2g(adult)
25-50 mg/kg (children)

20. Prevention Protective clothes Using long nozzle during spraying
Prevent eating during work
Washing after work

21. Summary OP’s action Effects Treatment
Block AChE, prolonged duration of ACh in synapse
Effects
Muscarinic, Nicotinic, CNS
Respiratory failure and Death result from this
Treatment
ABC’s, Decontamination, Atropine