Objective: Alcohol consumption (alcohol preference or alcohol intake) in animals is an index of human drinking behavior. Cocaine is the most frequently abused drug at present. Therefore, an increasing number of cases demonstrating concurrent use of alcohol and cocaine is being noted. We examined whether cocaine affects alcohol consumption and studied the mechanism of change in alcohol consumption following cocaine administration.
Method: We measured alcohol consumption in inbred mice, C57BL/6J and C3H/HeJ, when 10 or 50 mg/kg cocaine was administered intraperitoneally once a day for 1 week. Then the rate of blood ethanol disappearance from C57BL/6J mice in vivo was measured. Also, liver alcohol dehydrogenase(ADH) and aldehyde dehydrogenase(ALDH) activity in vitro were measured in the C57BL/6J mice.
Results: Following 50 mg/kg cocaine administration, alcohol consumption was reduced in C57BL/6J mice, but there was no clear change in C3H/HeJ mice. The rate of blood ethanol disappearance was not changed by pretreatment with cocaine. Neither liver ADH nor ALDH activity was changed by repeated cocaine administration.
Conclusions: The present study showed that repeated cocaine administration decreased alcohol consumption in C57BL/6J mice without altering the metabolism of ethanol.