RITANSERIN, A CENTRAL 5-HT2 ANTAGONIST, IN HEAVY SOCIAL DRINKERS - DESIRE TO DRINK, ALCOHOL INTAKE AND RELATED EFFECTS

Ritanserin, a 5-HT2 receptor antagonist, decreased alcohol intake in s ome, but not all, animal studies and in an open clinical study. We tes ted the short-term effects of ritanserin in 39 (35 male, four female) heavy social drinkers (consuming at least 28 drinks/week), aged 19-63 years, who were not seeking treatment. After an intake assessment, the y received placebo for 7 days in a single-blind baseline. They were th en randomly assigned to one of three double-blind treatments for 14 da ys: ritanserin 5 mg/day (n=12), ritanserin 10 mg/day (n=13) or placebo (n=14). Subjects recorded daily outpatient alcohol intake. Feelings o fintoxication and interest, desire, craving and liking for alcohol wer e rated retrospectively at each weekly study visit. Experimental drink ing sessions were conducted after baseline (EDS(1)) and treatment (EDS (2); in each session subjects were offered 18 mini-drinks (total=six s tandard) and rated their desire to drink, intoxication and mood (POMS) . Outpatient results: ritanserin 5 mg/day decreased desire and craving for alcohol (vs. baseline, p<0.05) but not alcohol intake. Liking of alcohol decreased from baseline with ritanserin 10 mg/day (p=0.01) and placebo (p=0.05). Changes in alcohol intake from baseline with ritans erin 10 mg/day (increase, p>0.05) and placebo (decrease, p>0.05) were different (p<0.05). EDS results: in EDS(2), desire ratings for the fir st three mini-drinks were lower after ritanserin 5 mg/day than after r itanserin 10 mg/day (p<0.05), but the decreases were not statistically significant when EDS(1) desire ratings were controlled for. Ritanseri n 10 mg/day increased alcohol-induced feelings of intoxication and fri endliness, compared with placebo (p<0.05). Both ritanserin 5 mg/day an d 10 mg/day enhanced alcohol-induced decreases in fatigue, compared wi th placebo (p<0.05). These results indicate that ritanserin may have d ifferential effects on alcohol intake, desire, craving and liking, int oxication and some of alcohol's effects on mood. However, they suggest that ritanserin has limited efficacy in reducing alcohol intake in he avy drinkers.