ORGANOPHOSPHATEPOISONING

Dr pramod sarwa

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INTRODUCTION

• Organophosphate widely used in agricultural sector as PESTICIDES.

• Nerve agents sarin, tabun, soman, VX, VE• Mortality a/w self-poisoning with pesticides:– 50-70 % in developing world– 0.3 % in developed world , jrccth

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classification

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PHYSIOLOGY REVISITED

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MECHANISM OF ACTION OF ORGANOPHOSPATE POISONING

Irreversibly bind to serine-OH group at the active site of acetylcholinesterase (AChE) establish covalent bond (phosphorylation)

↓AGING: loss of alkyl group + strengthening of

covalent bond↓

Phosphorylated AChE is very stable↓

Inhibition of enzyme activity accumulation of ACh in the synapse and NMJ

↓Overstimulation of cholinergic receptors

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CLINICAL PRESENTATION

MUSCARINIC: SLUDGES-SalivationL-LacrimationU-UrinationD-DiarrhoeaG-GI upsetE-Emesis

NICOTINIC: MATCHM-Muscle weakness

and fasciculationA-Adrenal medulla

activity ↑T-TachycardiaC-Cramping of skeletal

muscleH-Hypertension

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