Trazodone increases arousal threshold in obstructive sleep apnoea

¹ Sleep Medicine Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Service de Pneumologie et Centre d'Investigation et de Recherche sur le Sommeil (CIRS), Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
² Sleep Medicine Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
³ Sleep Medicine Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA; and Dept of Thoracic Medicine, Chang Gang Memorial Hospital, Taipei, Taiwan

^* To whom correspondence should be addressed. E-mail: rheinzer{at}post.harvard.edu.

	Abstract

A low arousal threshold is believed to predispose to breathing instability during sleep. We hypothesized that trazodone, a non-myorelaxant sleep promoting agent, would increase the effort-related arousal threshold in obstructive sleep apnoea (OSA) patients.

Nine OSA patients (age 49±9 yr AHI 52±32 events·h^-1) were studied on two nights, one with trazodone 100mg and one with a placebo, in a double blind randomized fashion. While on CPAP, repeated arousals were induced: 1) by increasing inspired CO₂ and 2) by stepwise decreases in CPAP level. Respiratory effort was measured with an esophageal balloon. End tidal CO₂ (EtCO₂) was monitored with a nasal catheter.

During trazodone nights compared with placebo nights, the arousals occurred at a higher EtCO₂ level (mean±sd): 54.9±4.3 vs 49.8±4.8 mmHg (p=0.038). When arousals were triggered by increasing inspired CO₂ level, the maximal esophageal pressure swing was greater: 19.4±4.0 vs 13.1±4.9 cmH2O (p=0.002) and the esophageal pressure nadir before the arousals was lower: -5.1±4.7 vs-0.38±4.2 cmH2O (p=0.02) with trazodone. When arousals were induced by stepwise CPAP drops, the maximal esophageal pressure swings before the arousals were not different.

Trazodone 100mg increases the effort-related arousal threshold in response to hypercapnia in OSA patients and allows them to tolerate higher CO₂ levels.

This article has been cited by other articles:

				G. S. Longobardo, C. J. Evangelisti, and N. S. Cherniack Influence of arousal threshold and depth of sleep on respiratory stability in man: analysis using a mathematical model Exp Physiol, December 1, 2009; 94(12): 1185 - 1199. [Abstract] [Full Text] [PDF]