TOXICOLOGY .10. - DRUG OVERDOSE - REDUCING THE LOAD

Objective: To review available information about various methods for reducing gastrointestinal absorption of a poison or drug. Data sources: Articles on overdose and accidental poisoning generated by the Australian Medlars Service and concentrating on the period between 1985 and 1990 were surveyed. Earlier studies were included if relevant. Study selection and data extraction: English language articles with an emphasis on studies using objective methods to measure individual and comparative efficacy of gastrointestinal decontamination techniques were selected. A total of 65 articles were reviewed. Data synthesis: Gastric emptying procedures (gastric lavage or emesis caused by syrup of ipecac) are only effective if performed within one hour of drug ingestion. Gastric lavage is superior to syrup of ipecac. Oral administration of activated charcoal is more effective than either gastric emptying procedure, and is recommended for most cases of poisoning. Cathartics (sorbitol) can be used with activated charcoal. Whole bowel lavage with polyethylene glycol is indicated in selected cases of potentially lethal overdose where the toxic substance cannot be absorbed by charcoal and has passed the pylorus. Conclusions: Children - syrup of ipecac can be given at home to children older than 12 months. Most children who reach hospital can be treated by charcoal alone. Adults - Most patients are managed with supportive care and, in the absence of contraindications, a single dose of activated charcoal if seen within four hours of ingestion of the poison or drug. Gastric lavage is used if the patient presents within one hour of ingestion and has clinical features of toxicity.