Extracorporeal elimination of poisons

Extracorporeal elimination may be indicated for severe or life-threatening poisonings involving:

• antiepileptic drugs—barbiturates, carbamazepine, lamotrigine, sodium valproate, topiramate
• aspirin
• baclofen
• lithium
• metformin
• toxic alcohols—methanol and ethylene glycol
• paraquat and other herbicides
• potassium
• theophylline
• sotalol.

If considering extracorporeal elimination, seek clinical toxicology and critical care advice—these techniques require specialised staff, equipment and monitoring, because they are invasive with risks of adverse events.

Techniques for extracorporeal elimination of poisons include:

• haemodialysis—intermittent or continuous haemodialysis may be beneficial in select poisonings, depending on the ratio of clearance by the machine to the endogenous clearance of the toxin. Machines with the highest flux are most effective, while low-flow continuous veno-venous haemodialysis gives low overall clearance. Haemodialysis may be beneficial for other reasons than removal of the drug or toxin, such as correction of acidosis in metformin poisoning
• haemoperfusion—rarely used because of limited benefit over haemodialysis and limited availability of activated charcoal cartridges
• plasmapheresis—despite early reports, there is no evidence for the use of plasmapheresis in the removal of drugs or toxins.