Oximes in acute organophosphorus pesticide poisoning: a systematic review of clinical trials.
BACKGROUND
Acute organophosphorus (OP) pesticide poisoning is widespread in the developing world. Standard treatment involves the administration of intravenous atropine and an oxime to counter acetylcholinesterase inhibition at the synapse, but the usefulness of oximes is uncertain.


OBJECTIVE
To assess the evidence on the use of oximes in OP poisoning.


METHODS
Systematic review.


METHODS
We searched Medline, Embase, and Cochrane databases (last check 01/02/02) for 'organophosphate' or 'oxime' together with 'poisoning' or 'overdose'. We cross-referenced from other articles, and contacted experts to identify unpublished studies. A Web search engine [www.google.com] was also used, with the keywords 'organophosphate', 'oxime', and 'trial' (last check 01/02/02).


RESULTS
We found two randomized controlled trials (RCTs) involving 182 patients treated with pralidoxime. The RCTs found no benefit with pralidoxime, and have been used to argue that pralidoxime should not be used in OP poisoning.


CONCLUSIONS
The RCT authors must be congratulated for attempting important studies in a difficult environment. However, their studies did not take into account recently clarified issues regarding outcome, and their methodology is unclear. A generalized statement that pralidoxime should not be used in OP poisoning is not supported by the published results. Oximes may well be irrelevant in the overwhelming self-poisoning typical of the tropics, but a large RCT comparing the current WHO-recommended pralidoxime regimen (>30 mg/kg bolus followed by >8 mg/kg/h infusion) with placebo is needed for a definitive answer. Such a study should be designed to identify any patient subgroups that might benefit from oximes.
Eddleston
M
M
Centre for Tropical Medicine, Nuffield Department of Clinical Medicine, University of Oxford, UK. eddlestonm@eureka.lk
Szinicz
L
L
Eyer
P
P
Buckley
N
N
D000208:Acute Disease; D001285:Atropine / Q000627:therapeutic use; D062787:Drug Overdose; D006801:Humans; D007306:Insecticides / Q000506:poisoning*; D009943:Organophosphorus Compounds; D010091:Oximes / Q000627:therapeutic use*; D011220:Pralidoxime Compounds / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic; D012107:Research Design
D007306:Insecticides; D009943:Organophosphorus Compounds; D010091:Oximes; D011220:Pralidoxime Compounds; D001285:Atropine; C028797:pralidoxime