ADVANTAGE OF HIGH-SURFACE-AREA CHARCOAL FOR GASTROINTESTINAL DECONTAMINATION IN A HUMAN ACETAMINOPHEN INGESTION MODEL

Objective: To compare the abilities of low-surface-area (LSA) vs 2 typ es of high-surface-area (HSA) activated charcoal given orally to adsor b acetaminophen in the gastrointestinal (GI) tract, as demonstrated by the impact of these agents on the serum levels and area under the cur ve (AUC) in a simulated human overdose model. Methods: The main arm of the study was a prospective double-blind crossover trial in which 6 v olunteers, serving as their own controls, ingested acetaminophen (50 m g/kg), followed randomly in 10 minutes by either powdered LSA charcoal (950 m(2)/g) or powdered HSA charcoal (2,000 m(2)/g) in a charcoal:dr ug ratio of 8:1. In a second arm of the study, 3 subjects additionally ingested an equal dose of a granular preparation of the HSA charcoal. Serial serum acetaminophen levels were analyzed at various intervals (30, 60, 90, 120, 180, 240, and 300 minutes postingestion), and a 5-ho ur AUC was calculated. The subjects also rated the charcoal preparatio ns for palatability. Results: Serum acetaminophen levels were lower at all measured times in the groups receiving both forms of the HSA char coal vs the LSA product. With the powdered HSA charcoal, comparison se rum levels were significantly lower at 120 minutes postingestion and a ll times thereafter (p < 0.05), reaching high significance at 4 and 5 hours (p < 0.001). The subjects receiving the granular HSA charcoal al so had consistently lower serum acetaminophen levels than did those re ceiving the LSA product, and the difference in mean serum levels was s ignificant at the 4- and 5-hour sample (p = 0.012). Compared with the LSA charcoal; at the 4-hour postingestion sample, serum acetaminophen levels were reduced by 44% to 85% by the powdered HSA charcoal. The to tal AUC for the 5-hour study period was also significantly reduced by the powdered HSA product (p = 0.005) and the granular HSA product (p = 0.043). All the subjects rated the powdered HSA charcoal to be more p alatable and easier to drink than the powdered LSA charcoal. Conclusio n: The surface area of oral activated charcoal is a major determining factor in its ability to limit acetaminophen absorption and to fulfill its adsorptive role in GI decontamination. In a human acetaminophen o verdose model, 2 types of HSA charcoal, when compared with equal doses of LSA charcoal, significantly reduced serum levels and total acetami nophen absorption as measured by the AUC.