The effect of activated charcoal on phenytoin pharmacokinetics

Abstract

To examine the effect of administration of oral activated charcoal with or without sorbitol on the elimination of phenytoin. Emergency department of a rural teaching institution. Eight normal volunteers. Subjects received 15 mg/kg phenytoin as an IV infusion. During the first phase of the study, oral activated charcoal was administered to a total dose of 140 g over a ten-hour period. During the second phase of the study, phenytoin alone was administered. Administration of activated charcoal resulted in a significant decrease in the area under the curve 0-inf (p = .008) and in total body clearance (P = .008). No difference in the effect on phenytoin pharmacokinetic parameters was noted when the charcoal was administered with or without sorbitol, but fewer gastrointestinal adverse effects were noted without sorbitol treatment. Oral activated charcoal was shown to affect phenytoin pharmacokinetic parameters. Further pharmacokinetic/pharmacodynamic studies are warranted to determine if activated charcoal results in a faster recovery from phenytoin toxicity.