Educational Forum - Controversies in the management of organophosphate pesticide poisoning

Acute poisoning with organophosphorous (OP) pesticides frequently causes ill-health and death all over the world. The treatment of OP poisoning is primarily aimed at reversing the effects of the compound by administration of atropine. A second class of compounds-oximes, capable of regenerating the active enzyme from the OP-cholinesterase complex, is also available to treat OP poisoning. Pralidoxime is the oxime most often used worldwide. The low propensity to aging with diethyl organophosphorous poisoning may allow reactivation of the acetylcholinesterase after several days, when the poison concentration drops. The usefulness of oximes has however been challenged over the past 20 years by physicians in many parts of the world who have failed to see any benefit in their clinical practice. We have carried out a systematic search to find clinical trials, both randomized and nonrandomized involving the management of OP poisoning. The clinical benefits of oximes in OP poisoning is not clear, being limited by the type of OP, poison load, time to start therapy and dose of oximes. Hence, one is left with a doubt as to whether one could use oximes at all in OP poisoning? A high-quality randomized clinical trial on a large number of subjects comparing the current World Health Organization-recommended regimen with a placebo to assess the value of pralidoxime in acute OP poisoning, may answer the above question.