Organophosphorus pesticides are used widely for agriculture, vector control, and domestic purposes.
Irreversible acetylcholinesterase inhibition:
Acute organophosphorus poisoning may induce multisystem toxicity leading to severe toxicity and death.
Acute cholinergic crisis:
Caused by the accumulation of acetylcholine at cholinergic synapses.
D = Defecation/diaphoresis
U = Urination
M = Miosis
B = Bronchospasm/bronchorrhea
E = Emesis
L = Lacrimation
S = Salivation
Monday = Mydriasis
Tuesday = Tachycardia
Wednesday = Weakness
Thursday = Hypertension
Friday = Fasciculations
Central nervous system (CNS):
Altered level of consciousness, respiratory failure, and seizures
Organophosphorus induced delayed polyneuropathy:
Unrelated to acetylcholinesterase inhibition and occurs because of inhibition of other enzymes, in particular neurotoxic target esterase characterised by demyelination of long nerves, when neurological dysfunction occurs 1-3 weeks after acute exposure, particularly motor dysfunction but also sensory dysfunction, which may be chronic or recurrent.