In vitro coadsorption of acetaminophen and N-acetylcysteine onto activated carbon powder.

The in vitro adsorption and coadsorption of acetaminophen and N-acetylcysteine using simulated gastric (pH 1.2) and intestinal (pH 7.0) conditions were examined for a range of charcoal-to-drug ratios between 1 and 7. Although both substances were adsorbed by the activated carbon, the adsorption of acetaminophen was greater than that of N-acetylcysteine for both acidic and neutral pH conditions. In the coadsorption studies, the acetaminophen was always adsorbed to a greater extent than the N-acetylcysteine. These results agree with previous in vivo studies that suggest that the concomitant use of N-acetylcysteine and activated carbon powder is an appropriate treatment for acetaminophen overdose.