Multiple-dose activated charcoal should not be recommended for patients in the rural developing world who have poisoned themselves with toxic pesticides or plants, since it has no effect on mortality. These are the conclusions of authors of an Article in this week's edition of The Lancet.
Organophosphorus pesticide self-poisoning is a major clinical and public-health problem across much of rural Asia. Of the estimated 500000 deaths from self-harm in the region each year, about 60% are due to pesticide poisoning. Many studies estimate that organophosphorus pesticides are responsible for around two-thirds of these deaths--a total of 200 000 a year.*
Treatment of self-poisoning involves resuscitation, antidotes, gastric decontamination and supportive care. However, there is no evidence that gastric contamination works, even though one form of this - using activated charcoal - is still widely applied. Self-poisoning in the developing world - where highly toxic pesticides and plants are ingested - presents different challenges from self-poisoning in the developed world, which is largely pharmaceuticals based.
Dr Michael Eddleston, Scottish Poisons Information Bureau, New Royal Infirmary, Edinburgh, UK, and Professor David Warrell, University of Oxford and John Radcliffe Hospital, Oxford, UK, and colleagues did a randomised controlled trial of 4632 self-poisoned patients in Sri Lanka, to establish whether activated charcoal reduced mortality in these patients. One group (1533 patients) received six 50g doses of activated charcoal at four hour intervals; the second group (1545) received one 50g dose of charcoal; and the third group (1554) received no charcoal. Pesticides had been digested by 2338 patients (51%), while 1647 (36%) had ingested yellow oleander (Thevetia peruviana) seeds.
The authors found that mortality did not differ between the groups. In the multiple-dose group 97 patients died (6.3%) compared with 105 (6.8%) in the no-charcoal group. No differences were noted for patients who took particular poisons, were severely ill on admission, or who presented early.
The authors conclude: "This randomised, controlled trial showed no benefit from routine administration of multiple-dose activated charcoal in Sri Lankan district hospitals. Most patients had ingested yellow oleander seeds or pesticides. Both poisons have major effects that are delayed for several hours.....absence of benefit was seen irrespective of the poison ingested or time to presentation."
In an accompanying Comment, Dr Peter Eyer, Walther Straub Institute of Pharmacology and Toxicology, University of Munich, Germany and Dr Florian Eyer, Technical University, Munich, Germany, say: "The results of Eddleston and colleagues study are relevant for the setting of a developing country, where most of these specific poisonings occur....There is an obvious need for robust toxicokinetic studies to select those poisons that are potentially amenable to multidose activated charcoal. Clinical science should meet basic science and vice-versa."
Notes to editors: See associated Review attached to full paper
Professor David Warrell, University of Oxford and John Radcliffe Hospital, Oxford, UK +44 (0)1865 221332/220968 / +44 (0) 7785 242978 E) firstname.lastname@example.org
Dr Michael Eddleston, Scottish Poisons Information Bureau, New Royal Infirmary, Edinburgh, UK contact by e-mail only E) email@example.com
Dr Peter Eyer, Walther Straub Institute of Pharmacology and Toxicology, University of Munich, Germany contact by e-mail only E) firstname.lastname@example.org
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