Phenobarbital as a hypocholesterolemic agent in the rat and rabbit

The administration of phenobarbital was observed to inhibit the rise in serum cholesterol that occurred in rats after thyroidectomy or hypophysectomy and in rabbits after inclusion of cholesterol in their diet. This hypocholesterolemic effect of phenobarbital was found to be due to its capacity to inhibit the intestinal absorption of cholesterol in both these species. We found no evidence to suggest that phenobarbital altered the endogenous process of cholesterol metabolism in either of these two species of animals.