OP are esters of: A-phosphoric, B-phosphonic, C-phosphorothiotic, or related acids. 1

OP are used as: 1-insecticides, 2-drugs and 3- chemical warfare: A-tabun GA, B-sarin GB, C-soman GD, D-GF E-VX 2

Intoxication from the OP can bring about four outcomes: 1-acute, cholinergic effect by inhibiting cholinesterases, (AChE) and (BChE). 2-OP-induced delayed neurotoxicity, (OPIDN). 3-Long term neuropsycological disorders. 4-Effects in muscles, weakness. 3

Increased cholinergic effects: SLUDGE, 1-salivation, vomiting, cramping, involuntary defecation, emesis, involuntary urination. 2-running nose, increased mucous, bronchoconstriction, cough, breathing difficulty, suffocation, and death. 3-lacrimation, vision difficulty, pain, sweating, 4-myosis, fatigue, muscle tremor, twitching & fasciculations, convulsions, 5-anxious, confusion, seizures, consciousness, headache, agitation. 4

Polyneuropathy: Lack of muscular coordination, tingling, numbness, fatigue, cramp-like pain, weakness and paralysis. OP act on Neuropathy Target Esterase, (NTE), so non anti- cholinesterases. Time: 1-4 weeks after contact. 5

Psychological disorders: Impairment of intellectual functioning, academic skills, abstraction, flexibility of thinking, coordination. Cause: Effect of OP on NTE. 6

Animal studies with Pyridostigmine Bromide, (PB). A-Histopathological & ultra structural, AChE inhibitor myopathy, organelle damage, myofibril disorganization, some necrosis. B-Presynaptic: ACh production & release, denervation withdrawal of nerves from the motor end plate, intrusion of glial cells in synapse, depletion of ACh vesicles. C-Postjunctional: current voltage, time response. 7

Two ways of medication: 1-Against the cause, 2-Symptomatic. 1-Antidote: A-AChE reactivators: a-pralidoxime chloride, (2-PAM), b-obidoxime. B-Reversible AChE OP, PB as ‘profilactic’ 8

2-Symptomatic medication: A-Parasympaticolytic-Atropine B-Tranquillisers-Diazepam. C-Oxygen, assisted ventilation. D-GK-11, non-competitive N-methyl-D-aspartate, (NMDA) receptor antagonist, (Lallement, et al 98). 9

Terror of a chemical war. Gulf War Veterans, (GWV), syndrome. Long-term effects from OP insecticides: A-The allergic response. B-Food contamination. C-Suspected Adverse Reaction, (SAR). D-Chronic and delayed effects of OP intoxication. 10

Mars. T, Syversen. T. General & Applied Toxicology, 2 nd Ed. Karczmar. A.G. Anticholinesterase agents. (1970). comiNEURO/tpoic286.htm vww.csis-scrs.gc.ca/eng/miscdocs/chemter_e.html