Global suicide rates may be reduced if the management of organophosphorus pesticide poisoning (OPP) were improved, according to a Review in an online edition of The Lancet.

Dr Michael Eddleston, Scottish Poisons Information Bureau, New Royal Infirmary, Edinburgh, Scotland, and team examined published articles on OPP during the period 1960-2006. They explained “Organophosphorous pesticide self-poisoning is a major clinical health problem across much of rural Asia. Of the estimated 500 000 deaths from self-harm in the region each year, about 60% are due to pesticide poisoning.”

Furthermore, they say that about 200,000 deaths, 60% of the total, are specifically due to OPP. Deaths as a result of accidental OPP are much less common, and seem to take place only in regions where the most toxic organophosphate pesticides are accessible.

Symptoms of OPP, caused by the over-stimulation of numerous receptors in the body, are:

– vomiting
– diarrhea
– sweating
– confusion
– agitation
– coma
– respiratory failure
– paralysis

There is still a great deal of uncertainty about the best use of common treatments for OPP, even though these treatments have been around for over 50 years. Commonly used treatments, such as atropine, oximes and diazepam have different levels of effectiveness, depending on which specific poison is affecting the patient. “However, consensus exists that early resuscitation with atropine, oxygen, respiratory support, and fluids are needed to improve oxygen delivery to tissues,” the authors say.

The authors believe larger trials are needed to see how effective magnesium sulphate might be – they suggest patients may benefit greatly from it. Gastric lavage (stomach pumping), a commonly used procedure for OPP, is only effective right at the beginning of the onset of symptoms. As the onset of symptoms is rapid the authors wonder how effective gastric lavage might be.

“Medical management of OPP is difficult, especially in resource poor locations where most of these patients present…We expect that in the next decade evidence from continuing research from Asia will finally provide clear guidance on how to treat OPP. Hopefully, this new guidance will include the use of novel antidotes that will reduce the case fatality from pesticide poisoning. However, some organophosphorus pesticides might prove very difficult to treat with current therapies, such that bans on particular pesticides could be the only method to substantially reduce the case fatality after poisoning,” the writers conclude.

lancet