Elimination

Methods:

• gastric lavage / emesis - these are used to remove the drug from the stomach. They are generally, valuable in all cases of self-poisoning presenting within 4 hours of ingestion, except if the abused substance is corrosive - paraquat being a notable exception. Gastric lavage is usually reserved for adults; forced emesis, using syrup of ipecacuanha, for children. In drugs which delay gastric emptying - salicylates, opiates, tricyclics, or sustained release theophylline preparations - these methods may be useful much longer after ingestion.
  
• activated charcoal
  
• peritoneal dialysis - may be used in poisoning due to lithium, ethylene glycol, methanol and ethanol poisoning, and in situations where urinary alkalinisation is inappropriate, for example, because of renal failure
  
  
• haemodialysis - usually more effective than peritoneal dialysis
  
  
• haemoperfusion - entails passing the drug through a column of activated charcoal or resin to adsorbs the drug. It may be of value in severe poisoning from barbiturates or theophylline
  
  
• forced alkaline diuresis - urinary pH kept greater than 7.5 - mainly in salicylate and phenobarbitone poisoning
  
  
• forced acid diuresis - urinary pH kept less than 7.0 - mainly in amphetamine poisoning