The effect of yogurt on acetaminophen absorption by activated charcoal and burnt toast

Although acetaminophen overdose can be treated with N‐acetylcysteine, activated charcoal is useful in preventing absorption of acetaminophen from the gut. Mixing activated charcoal with yogurt may make the dose more palatable. We investigated effects of yogurt on absorption of acetaminophen by burnt toast or activated charcoal in intestinal fluid using an in vitro model. The aliquots of phosphate buffer saline (PBS) were supplemented with high concentrations of acetaminophen after adjusting the pH to 7.2 (to mimic intestinal fluid). Then specimens were treated with various dosages (15 mg/mL, 25 mg/mL, or 50 mg/mL) of activated charcoal or burnt toast. A small amount of fluid was withdrawn at 0, 5, 10, 20, and 30 min and acetaminophen concentrations were measured by the fluorescence polarization immunoassay (FPIA). We also treated other aliquots of PBS buffer containing acetaminophen with activated charcoal and yogurt or burnt toast and yogurt. Then small aliquots were withdrawn at specific time intervals to determine concentrations of acetaminophen. Activated charcoal was very effective in removing acetaminophen from intestinal fluids and the presence of yogurt insignificantly affected such absorptions. In contrast, burnt toast had a modest effect on removing acetaminophen from fluids but yogurt significantly increased the capability of burnt toast to absorb acetaminophen. However, the activated charcoal/yogurt combination is more effective than the burnt toast/yogurt combination for absorbing acetaminophen. J. Clin. Lab. Anal. 21:393–397, 2007. © 2007 Wiley‐Liss, Inc.