Efficacious Oxime for Organophosphorus Poisoning: A Minireview

Oximes are well known as acetylcholinesterase reactivators and are used in organophosphorus poisoning to reactivate inhibited acetylcholinesterase. Therapeutically available oximes, namely, pralidoxime (2-PAM), obidoxime, trimedoxime and Hagedorn oxime (HI-6), have no broad-spectrum activity against structurally different kinds of organophosphorus anticholinesterases. The widely used oxime, 2-PAM, is least effective. The focus of the review is to find an oxime that is broad spectrum and superior to the presently available oximes for the treatment of organophosphorus poisoning. Numerous oxime-based reactivators have been synthesized in laboratories in Croatia, United States of America, Israel and most recently in Czech Republic. Some experimental oximes synthesized in Czech Republic and named as K-series of oximes have been found promising. Among them, K-27 and K-48 have higher or comparable efficacy to all available oximes though it is not effective against all organophosphorus (OP) nerve agents. They are also efficacious in pretreatment protocol for OP anticholinesterases. K-27 oxime is a promising candidate to replace therapeutically available oximes with respect to insecticide/pesticide organophosphorus poisoning. K27 and K48 may be candidates to replace the only approved pretreatment drug, pyridostigmine, in military combat medicine for OP nerve agent.