An Evaluation of the Effect of Repeated Doses of Oral Activated Charcoal on Salicylate Elimination

The authors investigated the effect of repeated doses of oral activated charcoal on salicylate elimination in six healthy volunteers. On two occasions (phase 1 and phase II; separated by one week) each subject received 1300 mg of aspirin as an aqueous solution. On the second occasion (phase II) each subject also received a total dose of 55 g of aqueous activated charcoal initiated 4 hours after salicylate administration (25 g initial dose, followed by three 10 g doses at two hour intervals). Serum salicylate levels were measured from one to twelve hours post aspirin ingestion. The pharmacokinetic analysis showed no significant change between phase I and phase II for either the salicylate elimination half‐life or the area under the concentration versus time curve from 4–12 hours post aspirin ingestion. Reasons for the lack of effect of repeated doses of charcoal on salicylate elimination are discussed and, these results cannot necessarily be extrapolated to the overdose situation. Further investigation is warranted to assess the effect of repeated doses of activated charcoal in the salicylate‐overdosed patient.