Activated charcoal surface area and its role in multiple-dose charcoal therapy

The study hypothesis was to prove that increasing the surface area (SA) of activated charcoal (AC) will enhance theophylline elimination in multiple-dose AC therapy. Five healthy, nonsmoking, nonmedicated, volunteer men ranging from the ages of 18 to 24 years old were entered onto the study. A prospective, randomized, crossover study was conducted with each subject serving as their own control. Subjects fasted overnight before receiving 8 mg/kg of intravenous theophylline at the beginning of a control phase and two study phases. No AC was administered in the control phase. Two experimental phases compared Actidose Aqua AC (1,500 m2/g; Paddock Laboratories, Inc, Minneapolis, MN) with Norit A Supra AC (2,000 m2/g; Norit NV, Amersfoort, the Netherlands). In each phase, 50 g of the AC was administered orally after the conclusion of the theophylline infusion. Subsequent 50-g doses of the AC preparation were administered at 4 and 8 hours after the initial dose of AC. Serial blood samples for theophylline level determinations were obtained at 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 10.0, and 12.0 hours after the completion of the theophylline infusion. For each of the three data sets, the absolute area under the absorption curve (A-AUC) was calculated to infinity using the trapezoidal rule. Additionally, the relative area under the absorption curve (R-AUC) was determined for each data set. Data were analyzed using repeated measures of analysis of variance (ANOVA) and Tukey's test. The alpha error was set at 0.05.(ABSTRACT TRUNCATED AT 250 WORDS)