1. Malathion Is Hydrolyzed by Plasma Carboxylases in Birds and Mammals but Not Insects1

2. Preferentially hydrolyzes aliphatic esters Malathion is a substrate
Carboxyl Esterases
Preferentially hydrolyzes aliphatic esters
Malathion is a substrate
Are inhibited by organophosphates
May also be called aliesterases 2

3. 0.5% solution in 78% isopropranolol is pediculicidal and ovicidal
Uses of Malathion
Insecticide
Therapeutics
Used as a lotion for Pediculus humanus capitis associated with pediculosis
0.5% solution in 78% isopropranolol is pediculicidal and ovicidal
Ovide is the brand name
Primoderm was the former brand name 3

4. Rapidly metabolized by birds and mammals
Malathion Metabolism
Rapidly metabolized by birds and mammals
Plasma carboxylases are involved
Insects do not possess the enzyme
Organophosphates inhibit malathion metabolism
Malathion is toxic to fish 4

5. P-F bond P-CN bond Phosphoester bond Anhydride bond Aryl Esterases
Are found in the plasma and liver
Hydrolyzes organophosphates at the
P-F bond
P-CN bond
Phosphoester bond
Anhydride bond 5

6. EPA And Organophosphates
Diazinon
No longer allowed to be manufactured for indoor use in as of March 1, 2001 or for garden use as of June 3, 2001
Found in Real Kill®, Ortho®, Spectracide®
Limited agricultural use is allowed
Chlorpyrifos (Dursban) has been phased out
Parathion has been phased out for agricultural use in the United States 6

7. NERVE AGENT VX Chemical name:
O-ETHYL-S-(2-DIISOPROPYLAMINOMETHYL)METHYL-PHOSHONOTHIOLATE
Trade name: PHOSPHONOTHIOIC ACID
NERVE AGENT VX

8. NERVE AGENT VX Chemical name:
O-ETHYL-S-(2-DIISOPROPYLAMINOMETHYL)METHYL-PHOSHONOTHIOLATE
Trade name: PHOSPHONOTHIOIC ACID

9. Organophosphates as Nerve Gas Agents in Chemical Warfare (1)
Extremely volatile agents such as sarin, tabun, soman, and agent VX may be used as nerve agents in chemical warfare.
Accumulation of ACh at cholinergic receptors produces effects reflecting stimulation of cardiac muscle, smooth muscles and glands. Such effects would be identical to those caused by muscarine poisoning.
Bradycardia and hypotension occur. However, in some cases, tachycardia may be observed, due to intense sympathetic discharge in response severe hypoxemia. 9

10. Organophosphates as Nerve Gas Agents in Chemical Warfare (2)
Irreversible inhibition of acetylcholinesterase by these agents produces accumulation of ACh at the end plate of skeletal muscle fibers. This in turn leads to depolarizing blockade of the NM nicotinic receptor. Skeletal muscle paralysis occurs. Movement is impossible. The diaphragm is also paralyzed. The individual eventually dies due to respiratory paralysis.
Pralidoxime, atropine, and removal of the person from the source of exposure are all to be employed in cases of posioning. 10