Central nervous system effects Initial stimulation
followed depression
by Restlessness anxiety ataxia psychosis convulsions
coma death
Management
Investigation
Treatment
Assay of cholinesterase (ChE) enzyme activity
Plasma (pseudo)
Erythrocyte (true)
More accurate Represent enzyme in nervous system Mild toxicity Moderate toxicity Severe toxicity
Inaccurate. Disturbed by other diseases
20-50% 10-20% less than 10%
Treatment 1-Care of respiration
Clear patent airway.
Suction of secretion.
Adequate ventilation.
Oxygenation.
2- Care of circulation I.V. fluid to avoid dehydration
3-Decontamination: Dermal
Removal of clothes Wash skin with soap and water or ethyle alcohol
GIT Gastine lavage after endotracheal entubation
4-Antidotal therapy A)Atropine Mechanisms: Mechanism Mechanisms: s: Competitive Competitive antagonist antagoni antagonist st of acetyle acetyle choline cholin cholinee at the
muscarinic receptor sites It cross B.B.B thus may have effect on CNS toxicity Dose: 2mg I.V and repeated every 10-15 10- 15 minutes until atropinization Drying of secretion Dilated Dilat ed pupil N.B. Proper oxygenation and cardiac monitoring are essential during atropine therapy
B- Oximes Pralidoxime (2 PAM)
Toxogonin
Used to antagonize the nicotinic effects of OP. But it can also reverse the muscarinic and CNS effects. Dose: Pralidoxime: 1gm I.V in saline Toxogonine: ampoule (250 mg) I.V can be repeated after 1-2 h up to three ampoules
Mechanism of action of oximes 1. Br Brea eak k the the bo bond nd.. 2. Direct Direct det detoxi oxifica ficatio tion n of O.P O.P. detoxif oxificat ication ion O.P.. 3. Have anticho cholin linergi ergic c effect ef fects. s. Have anti antich anticholi oliner nergic gic effects effe cts
