As a result, very early in the absorption phase and prior to reaching equilibrium, BAC in arterial blood is higher than in venous blood, with the greatest arteriovenous difference being ~ 0.2 g/L within 10 minutes after drinking on an empty stomach (99). Eventually, the circulation and tissue concentrations equilibrate. However, alcohol continues to be metabolized. Eventually, the direction of diffusion flips, and the tissue water space becomes the “source” of alcohol in the bloodstream (100–102).
