Changes of cyclic alternating pattern (CAP) parameters in situational insomnia under brotizolam and triazolam

M. G. Terzano, L. Parrino, M. Boselli, S. Dell'Orso, M. Moroni, M. C. Spaggiari

Research output: Contribution to journalArticlepeer-review


The standardized scoring criteria of sleep can serve as a rough tool for monitoring the effects of psychoactive compounds, both in normal sleepers and in insomniac patients. More sensitive information on the impact of perturbing factors and drugs during sleep is supplied by the cyclic alternating pattern (CAP) parameters. In particular, CAP rate, which measures the amount of arousal instability during NREM sleep, has been proved of high reliability in a variety of clinical and pharmacological settings. The present study aimed at evaluating the activity of brotizolam (Br) 0.25 mg and triazolam (Tr) 0.25 mg on both conventional and CAP parameters in a model of situational insomnia of intermediate severity. Six middle-aged healthy subjects (three males and three females, aged 40-55 years) with no complaints about sleep, underwent a polysomnographic investigation according to a double-blind crossover design: placebo without noise (night 1), placebo with noise (night 2), brotizolam or triazolam without noise (nights 3 and 5), brotizolam or triazolam with noise (nights 4 and 6). The unperturbed nights consisted of standard recording conditions in a sound-protected sleep laboratory, whereas situational insomnia was accomplished by means of continuous white noise at 55 dBA delivered throughout the night. Subjects received medication orally at bedtime. An interval of at least 48 h was secured between consecutive recordings in the same individual. Compared to baseline conditions, situational insomnia was characterized by a shorter amount of total sleep (-40 min) and by an extension of intrasleep awakenings (+62 min). Compared to triazolam, during the perturbed nights brotizolam guaranteed a longer duration of sleep time (Br: 462 min versus Tr: 443 min), a reduced length of intrasleep awakenings (Br: 14 min versus Tr: 34 min) and a lower percentage of stage 1 (Br: 3.6% versus Tr: 5.8%). However, on the basis of the statistical information supplied by the conventional sleep parameters, the drug nights could not be clearly discriminated from the placebo nights. By contrast, both brotizolam and triazolam significantly reduced (P

Original languageEnglish
Pages (from-to)237-243
Number of pages7
Issue number3
Publication statusPublished - Aug 1995


  • Brotizolam
  • Cyclic alternating pattern
  • Insomnia
  • Sleep
  • Triazolam

ASJC Scopus subject areas

  • Pharmacology

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