Prophylaxis against organophosphorus poisoning

The terms prophylaxis and pre-treatment of organophosphorus (OP) poisoning (including nerve agent poisoning) are discussed. Some treatments to increase the resistance of an organism against the effects of these OP poisons have been developed and are based on the administration of reversible cholinesterase inhibitors. Reversibly inhibited carbamylated cholinesterase enzyme is resistant to subsequent inhibition by OP; it quickly and spontaneously decarbamylates and, thus, serves as a source of normal (uninhibited) enzyme. The administration of therapeutic drugs (antidotes) used for the treatment of OP intoxication is another approach for prophylaxis. Treatments causing a decrease of the level of OP in the blood stream are yet another approach for prophylaxis. Three prophylactics that have been introduced for use by military forces are pyridostigmine bromide alone, pyridostigmine with anticholinergics (PANPAL), and HI-6 for transdermal administration (TRANSANT). Administration of cholinesterase preparations and transdermal administration of physostigmine are new treatment modalities under intensive research