Effect of midazolam, flunitrazepam, and placebo against midwinter insomnia in northern Norway

Abstract

Forty-three outpatients with "midwinter insomnia" (an early type insomnia commonly seen north of the Polar Circle when the sun stays below the horizon) were randomly allocated to one of three treatment groups, receiving either 15 mg midazolam, 1 mg flunitrazepam, or placebo, for 5 nights, double blind, after 3 nights without drug. In all three groups, this was followed by 5 nights on placebo (single blind). Several subjective sleep variables were recorded every morning, some variables also at noon. Placebo had practically no effect on any sleep variable, whereas both active drugs markedly improved sleep with regard to the following variables: sleep latency, number of awakenings, total duration of sleep, quality of sleep, total evaluation of sleep, and feelings of drowsiness in the morning and at noon. In the withdrawal period, patients who had received active drug showed a deterioration of sleep on most variables, but not beyond the baseline level. A true "rebound insomnia" could thus not be demonstrated. There was no significant difference in any of the variables between midazolam and flunitrazepam treatment. Side effects were reported by very few patients. Midazolam seems to be as effective as flunitrazepam in this type of insomnia, in spite of its much shorter biological half-life.