ABSTRACT
STUDY OBJECTIVE: To determine if the presence of N-acetylcysteine reduces the ability of activated charcoal to adsorb acetaminophen both in the absence and presence of a coingestant. DESIGN: In vitro laboratory study. SETTING: University hospital research laboratory. MEASUREMENTS AND MAIN RESULTS: The adsorption of acetaminophen and salicylic acid by activated charcoal in the presence and absence of N-acetylcysteine was measured in vitro. Acetaminophen and salicylic acid analyses were conducted with high-performance liquid chromatography. Adsorption data were compared using the appropriate parametric statistical test. The addition of N-acetylcysteine significantly decreased the binding of acetaminophen by activated charcoal (p<0.005). When salicylic acid was added to simulate a coingestant, N-acetylcysteine significantly decreased salicylate adsorption by charcoal (p<0.001). CONCLUSIONS: The presence of N-acetylcysteine reduces the ability of activated charcoal to adsorb acetaminophen and coingestants. In vivo data will be required to determine the clinical relevance of these interactions.