Gastric contents alter blood alcohol levels and clearance after parenteral ethanol

Several different substances, including water, charcoal, fructose, montmorillonite clay, and liquid diets used for chronic ethanol exposure, were given intragastrically to rats, followed by a low dose of ethanol injected subcutaneously. Peak blood alcohol levels (BAL) and ethanol clearance rates were found to differ depending upon the type of gastric contents. As expected, fructose lowered peak BAL and increased ethanol clearance, and charcoal lowered peak BAL, but decreased ethanol clearance. Two liquid diets, Shorey and Sustacal, when compared to an intragastric water load, also lowered peak BAL and increased ethanol clearance of subcutaneously-administered ethanol. The difference between intragastric water and Shorey liquid diet was also seen when ethanol was administered intravenously, suggesting that absorption of ethanol from the subcutaneous site was not being affected. When sleep-inducing doses of ethanol were given subcutaneously, intragastric substances did not produce differences in sleeptimes. In in vitro studies, only charcoal was able to bind ethanol, presumably by absorption onto charcoal particles. Volume of distribution measurements were inversely related to the peak BALs measured at 60 minutes after injection, suggesting that ethanol was partitioning between the blood and stomach contents. We conclude that the presence in the stomach of various substances can lower peak BAL and increase ethanol clearance in a rapid fashion, primarily through a change in volume of distribution and possibly through a rapid change in stomach or liver metabolism of ethanol.