Lowering of blood ethanol by activated carbon products in rats and dogs

Earlier studies on the effects of activated carbon (charcoal) on blood alcohol levels (BAL) in animals have been conflicting. The present study was designed to study the effects of a commercially available product (Charcoaid) and a new patented product (Alcosorb), in capsules and in suspension on the BAL of rats and dogs. We compared peak BAL and the regression of BAL with time during ethanol clearance in rats given 1.5 g/kg of carbon products in sorbitol intragastrically, followed 5 min later by 3.5 g/kg ethanol intragastrically. Peak BAL were significantly higher after Charcoaid 1 h after intubation, compared to Alcosorb and sorbitol (vehicle for the charcoal suspension). A study in which ethanol was given intraperitoneally instead of intragastrically showed no differences in ethanol BAL produced by the intragastric carbon treatments. In a crossover study using Beagle dogs, 780 mg capsules of carbon products ("low dose") given 5 min before ethanol had no significant effect on BAL. A "high" dose of 20 g of charcoal products suspended in water, followed by ethanol intragastrically, was also ineffective in lowering blood ethanol. However, carbon products suspended in a water/ethanol vehicle (20% w/v) did significantly lower peak BAL. We conclude that carbon products significantly lower BAL in rats and dogs, and that in rats, Alcosorb and sorbitol produce a greater BAL lowering effect than Charcoaid for a brief time after administration. The mechanisms of the BAL lowering effect by sorbitol and charcoal products are probably different.