Charcoal-a Low-cost Option To Treat Oleander Poisoning

Research from Sri Lanka in this week’s issue of THE LANCET highlights how repeated doses of charcoal could reduce deaths from oleander-seed poisoning by up to 70%. The authors of the study suggest that charcoal could also be effective in treating poisoning from drugs used in Western populations with similar effects to oleander-seed poisoning, such as digoxin and digitoxin, or with drugs that are eliminated from the body in a similar fashion.

Deliberate self-poisoning with yellow oleander seeds is common in Sri Lanka, causing around 2000 deaths every year. Oleander poisoning results in severe toxicity in the heart and has a death rate of about 10%. Specialised treatment (such as temporary pacemakers and the use of antibodies) is expensive and not available in rural settings. H J de Silva from the University of Kelaniya, Sri Lanka, and colleagues investigated whether multiple-dose charcoal could be a low-cost option for treating oleander poisoning; charcoal causes the binding of harmful glycosides in the gut, thereby aiding in their elimination from the body.

Around 400 people admitted to hospital with oleander poisoning were given one dose of activated charcoal (standard treatment) and then randomly assigned either 50 g of activated charcoal four times a day for 3 days or sterile water (as a placebo). There were significantly fewer deaths in the treatment group (2.5%) compared with those given placebo (8%). Charcoal treatment also resulted in fewer secondary outcomes (life-threatening cardiac arrhythmias, dose of atropine used, need for cardiac pacing, admission to intensive care) than placebo.

H J de Silva comments: “Multiple-dose activated charcoal is safe and effective in reducing death and life-threatening cardiac arrhythmias after yellow oleander poisoning, and should be given to all patients who have ingested yellow oleander seeds. Expensive interventions, such as cardiac pacing and antidigoxin antibody Fab fragments, could be reserved for patients who have dangerous arrhythmias [irregular heart beats] at the time of presentation with poisoning, or those who develop arrhythmias despite treatment with activated charcoal.”

Co-investigator Jeff Aronson adds: “Our results suggest that multiple-dose activated charcoal could also be of use in the treatment of patients who have been poisoned with other cardiac glycosides. A previous study in 23 patients and a few anecdotal reports have shown that charcoal increases the clearance rate of digoxin (Lanoxin), and experimental evidence shows much the same effect on digitoxin clearance. Multiple-dose charcoal should also be useful in treating poisoning with other drugs that are eliminated from the body by being secreted into the gut, as the cardiac glycosides are.”