Decreased alcohol consumption by verapamil in alcohol preferring rats.

1. Calcium channel blockers have been proposed, in addition to inhibiting the influx of Ca++ into the cells, to possess a wide variety of pharmacological effects, including interference with certain neurotransmitters involved in mood, mental disorders and alcohol craving. Further, it has been documented that certain neurotransmitters are involved in alcohol craving both in animals and humans. 2. To investigate the effects of Ca(++)-channel antagonist on alcohol preference, verapamil in three doses (5, 10 and 15 mg/kg) was injected (S.C.) twice daily over a period of one day in alcohol-preferring (P) and alcohol non-preferring (NP) rats at 9:00 a.m. and 4:00 p.m. 3. Water, alcohol and food intake were monitored. 4. Our results show that verapamil in doses of 10 and 15 mg/kg significantly (p less than 0.02 and 0.01, respectively) reduced the intake of ethanol and increased the intake of water by P rats. However, injection of an equal volume of saline did not change the pattern of alcohol intake. 5. These results suggest that a (++(+)-channel blocker such as verapamil, could, at least partially, attenuate alcohol preference in alcohol preferring rats. It is possible that verapamil exerts an inhibitory effect on alcohol preference by interfering with Ca++ channels, blocking serotonin uptake or through another mechanism(s).