Oral Activated Charcoal in the Treatment of Intoxications

Abstract

Activated charcoal has an ability to adsorb a wide variety of substances. This property can be applied to prevent the gastrointestinal absorption of various drugs and toxins and to increase their elimination, even after systemic absorption. Single doses of oral activated charcoal effectively prevent the gastrointestinal absorption of most drugs and toxins present in the stomach at the time of charcoal administration. Known exceptions are alcohols, cyanide, and metals such as iron and lithium. In general, activated charcoal is more effective than gastric emptying. However, if the amount of drug or poison ingested is very large or if its affinity to charcoal is poor, the adsorption capacity of activated charcoal can be saturated. In such cases properly performed gastric emptying is likely to be more effective than charcoal alone. Repeated dosing with oral activated charcoal enhances the elimination of many toxicologically significant agents, e.g. aspirin, carbamazepine, dapsone, dextropropoxyphene, cardiac glycosides, meprobamate, phenobarbitone, phenytoin and theophylline. It also accelerates the elimination of many industrial and environmental intoxicants. In acute intoxications 50 to 100g activated charcoal should be administered to adult patients (to children, about 1 g/kg) as soon as possible. The exceptions are patients poisoned with caustic alkalis or acids which will immediately cause local tissue damages. To avoid delays in charcoal administration, activated charcoal should be a part of first-aid kits both at home and at work. The 'blind' administration of charcoal neither prevents later gastric emptying nor does it cause serious adverse effects provided that pulmonary aspiration in obtunded patients is prevented. In severe acute poisonings oral activated charcoal should be administered repeatedly, e.g. 20 to 50g at intervals of 4 to 6 hours, until recovery or until plasma drug concentrations have fallen to non-toxic levels. In addition to increasing the elimination of many drugs and toxins even after their systemic absorption, repeated doses of charcoal also reduce the risk of desorbing from the charcoal-toxin complex as the complex passes through the gastrointestinal tract. Charcoal will not increase the elimination of all substances taken. However, as the drug history in acute intoxications is often unreliable, repeated doses of oral activated charcoal in severe intoxications seem to be justified unless the toxicological laboratory has identified the causative agent as not being prone to adsorption by charcoal. The role of repeated doses of oral activated charcoal in chronic intoxication has not been clearly defined.(ABSTRACT TRUNCATED AT 400 WORDS)

Charcoal Is a Sensitive, Specific, and Stable Marker for the Diagnosis of Aspiration in Hamsters

“…It prevents the gastrointestinal absorption of various drugs and toxins and increases their elimination even after systemic absorption (14,15).…”

Evaluation of Administration of Activated Charcoal in the Home

“…2 To this list may be added suggested contraindications of substances that are not absorbed to AC (eg, alcohols, iron, lithium) and after ingestion of a caustic substance. 7,17 Serious complications of AC administration in the hospital setting are rare but include aspiration of the AC and AC containing empyema. 18 In our case series of AC administration in the home, no patient reported respiratory difficulty or other evidence of aspiration after 72 hours via telephone follow-up.…”

The effect of cholestyramine and activated charcoal on glipizide absorption.

“…Absorption of oral anticoagulants, digitalis glycosides, and diuretics, for example, may be affected to a clinically significant degree (Hunninghake et al, 1982;Jahnchen et al, 1978;. Many, but not all drugs, have been shown to adsorb to activated charcoal in vitro and in vivo and it is used in the treatment of acute intoxications (Neuvonen & Olkkola, 1988). Like cholestyramine, activated charcoal is also effective in lowering serum cholesterol concentration in hypercholesterolaemic patients (Neuvonen et al, 1989).…”