C a m i l l e R e n e e

D r . A . S . , M D .

S a i n t J a m e s S c h o o l o f M e d i c i n e

ORGANOPHOSPHATES

Chemical Structure

ORGANOPHOSPHATES

Mechanism of Action

• Inactivates acetylcholinesterase by phosphorylating its serine hydroxyl group

• There is eventual overstimulation of Ach receptors because of excess amounts of Ach in the synaptic cleft in cholinergic synapses

• Acetylcholine is crucial for correct nerve function in insects and mammals, but can be pathological in excess

ORGANOPHOSPHATES

Organophosphate Poisoning

ORGANOPHOSPHATES

• Potent nerve agent and a common cause of poisoning across the globe

• Frequently used in suicides in agricultural areas

• PON1 (Paraoxonase) is the enzyme used to metabolize organophosphates in the human body

• Can increase risk for developing Alzheimer’s Disease or ADHD even at low levels of exposure

Signs and Symptoms

• When muscarinic synapses are affected:

SLUDGEM

(salivation, lacrimation, urination, defecation, gastrointestinal motility, emesis, and miosis)

• Can also cause pervasive developmental disorder, morphological abnormalities, and delayed mental development in the fetuses of pregnant women

ORGANOPHOSPHATES

Signs and Symptoms

ORGANOPHOSPHATES

• When cholinergic synapses in the brain are affected:

1. Cholinergic syndrome – symptoms similar to SLUDGEM along with dyspnea, bradycardia, and cyanosis

2. Intermediate syndrome – muscular weakness in face, neck flexor, and respiratory muscles

3. Organophosphate-induced delayed polyneuropathy – shooting pain in legs as temporary paralysis begins

4. Organophosphate-induced neuropsychiatric disorder – peripheral neuropathy, mood change, autonomic dysfunction

ORGANOPHOSPHATES

ORGANOPHOSPHATES

Diagnostic Tests

• Differential diagnoses include viral gastroenteritis and mushroom toxicity

• Diagnosis is confirmed by assessing acetylcholinesterase, butyrylcholinesterase and neuropathy target esterase metabolites in the blood

ORGANOPHOSPHATES

Treatment

ORGANOPHOSPHATES

• Atropine: a competitive muscarinicacetylcholine receptor antagonist that blocks acetylcholine receptors, preventing patient death

• Carbamates may be used as a pre-treatment

Parathion

• Powerful organophosphate insecticide

• Toxic to humans at high doses

• Degrades rapidly via hydrolysis when exposed to air, sunlight, etc.

• Has been used as a warfare agent in Zimbabwe

ORGANOPHOSPHATES

ORGANOPHOSPHATES

Source List

1. Yo Ladies! http://www.yoladies.com/health/2010/05/organophosphates-addadhdautism-is-there-a-link.html

2. Wikipedia. http://en.wikipedia.org/wiki/Organophosphate

3. Wikipedia. http://en.wikipedia.org/wiki/Organophosphate_poisoning

4. Medscape. http://emedicine.medscape.com/article/167726-differential

5. Buzzle. http://www.buzzle.com/articles/shooting-pain-in-leg.html

6. The Indian Express. http://archive.indianexpress.com/news/new-device-can-detect-cancer-or-any-disease-in-10-minutes-uk-scientist/1121244/