Polysomnography during withdrawal with clomethiazole or placebo in alcohol dependent patients--a double-blind and randomized study.

INTRODUCTION: The present study was designed to assess if the routine application of clomethiazole to ameliorate withdrawal symptoms in chronic alcohol dependent patients perpetuates sleep disturbances.

METHODS: Twenty inpatients with alcohol dependence according to DSM-IV criteria received clomethiazole or placebo in a double-blind, randomized design upon admission. 11 patients were randomized to the clomethiazole group and 9 patients to the placebo group. During the first 5 days of treatment the patients received either clomethiazole (1st day: 3 x 384 mg, 2nd day: 4 x 384 mg, 3rd day: 3 x 384 mg, 4th day: 2 x 384 mg and 5th day: 1 x 384 mg) or placebo capsules at constant intervals. The patients spent two consecutive nights in the sleep laboratory at each of three assessment times: the first time at the beginning of abstinence (night 1 and 2, T0), the second time 6 days later (i. e. after 5 days of treatment and one day of discontinuation of clomethiazole or placebo: nights 6 and 7, T1) and the third time after 13 days (nights 13 and 14, T2). The first night at each of the three assessment times was an adaptation night.

RESULTS: During the first two weeks of abstinence, the analysis of variance demonstrated a significant variation of Rapid Eye Movement (REM) sleep variables in the clomethiazole group. The placebo group showed no such variation. Clomethiazole evidently had a pronounced REM sleep suppressing effect, whereas the discontinuation of clomethiazole led to a REM sleep rebound. Furthermore, analysis of sleep continuity and sleep architecture variables showed that the clomethiazole group had significantly disturbed sleep at T1 in comparison to the placebo group. Simultaneous statistical testing with alcohol intake as covariate reduced the test power so that contrasts between the groups became nonsignificant.

CONCLUSIONS: The REM sleep results are in line with earlier findings that REM sleep disinhibition in primary alcohol dependency is partly due to a REM sleep rebound after withdrawal from medication. Differences in the polysomnographic variables of sleep continuitiy and sleep architecture at T0 and T1 found between the clomethiazole and the placebo patients correspond to rebound insomnia following discontinuation of clomethiazole. Our findings indicate that drugs enforcing GABAergic neurotransmission may perpetuate the neuroadaptative effects caused by chronic alcohol consumption.