Influence of chlordiazepoxide on alcohol consumption in mice.

In a free-choice situation, chlordiazepoxide (CDP; 12.5 or 25 mg/100 ml; groups B or C), when incorporated in ethanol solutions (2 to 20%, v/v), caused a significant decrease in ethanol preference index (P.I.). This was probably due to the combined CNS effects of both drugs rather than a taste effect, since the mice did not discriminate between aqueous CDP solutions and water. However, when the mice had prior exposure to ethanol and CDP was incorporated intermittently, no significant decreases in P.I. resulted. In a no-choice situation, ethanol intake was increased only on the first day of each intermittent incorporation of CDP (3 days for each 6-day cycle), being more persistent in group B (2 to 15% ethanol) than in group C (2 to 6.5%). Ethanol intake decreased in group C when alcohol concentrations exceeded 10%. The "first-day" CDP effect also occurred in the no-choice situation of an ethanolic liquid diet. Possible factors for this effect are discussed. Thus the effects of CDP on alcohol consumption in non-deprived mice vary with experimental designs.