Self-administration of pentobarbital in light and moderate alcohol drinkers

Preference for a moderate dose of pentobarbital was assessed in light and moderate alcohol drinkers using a double-blind, placebo-controlled laboratory choice procedure. Sixteen light drinkers (less than six alcoholic drinks per week) and 13 moderate drinkers (six or more drinks per week) participated in a seven-session study in which they first sampled capsules containing pentobarbital (150 mg) or placebo and then chose and ingested the capsule they preferred. Subjective and behavioral measures were obtained at regular intervals during each session to characterize the drug's effects. Both groups chose pentobarbital less often than placebo: Mean pentobarbital choice in light drinkers was 20.8% and in moderate drinkers was 38.5%. Pentobarbital choice and drug liking ratings were highest among male moderate drinkers but still did not exceed placebo levels. The drug did not increase scores on standardized measures of drug euphoria, even among the most frequent choosers or the heaviest alcohol consumers. The results extend previous reports showing that individuals without histories of drug abuse, even those who are moderate consumers of alcohol, do not self-administer sedative/anxiolytic drugs or experience their effects as euphorigenic.