The effect of phenobarbital on cholesterol gallstones in hamsters.

This experimental study was undertaken to follow the influence of phenobarbital on bile chemistry and gallstone formation. Phenobarbital (400 mg/kg/day) was administered to golden hamsters receiving a diet known to induce cholesterol gallstones. After a 28-day period none of the control animals had gallstones whereas five of 12 animals with added phenobarbital developed stones. Ten of 19 animals on the lithogenic diet formed gallstones but when phenobarbital was added gallstones occurred in 16 of 19 hamsters. The administration of phenobarbital resulted in the production of bile which was relatively more saturated with cholesterol, the bile salt + phospholipid: cholesterol of 24.8 +/- 12.7 in control animals altering to 9.1 +/- 6.2 in animals receiving phenobarbital. Hepatic bilirubin uridine diphosphate-glucuronyl transferase activity was not increased in animals on phenobarbital. It was concluded that, in the hamster at least, there is no indication that large doses of phenobarbital will reduce the potential for gallstone formation.