TY - JOUR T1 - Trazodone increases arousal threshold in obstructive sleep apnoea JF - European Respiratory Journal JO - Eur Respir J SP - 1308 LP - 1312 DO - 10.1183/09031936.00067607 VL - 31 IS - 6 AU - R. C. Heinzer AU - D. P. White AU - A. S. Jordan AU - Y. L. Lo AU - L. Dover AU - K. Stevenson AU - A. Malhotra Y1 - 2008/06/01 UR - http://erj.ersjournals.com/content/31/6/1308.abstract N2 - A low arousal threshold is believed to predispose to breathing instability during sleep. The present authors hypothesised that trazodone, a nonmyorelaxant sleep-promoting agent, would increase the effort-related arousal threshold in obstructive sleep apnoea (OSA) patients. In total, nine OSA patients, mean±sd age 49±9 yrs, apnoea/hypopnoea index 52±32 events·h−1, were studied on 2 nights, one with trazodone at 100 mg and one with a placebo, in a double blind randomised fashion. While receiving continuous positive airway pressure (CPAP), repeated arousals were induced: 1) by increasing inspired CO2 and 2) by stepwise decreases in CPAP level. Respiratory effort was measured with an oesophageal balloon. End-tidal CO2 tension (PET,CO2) was monitored with a nasal catheter. During trazodone nights, compared with placebo nights, the arousals occurred at a higher PET,CO2 level (mean±sd 7.30±0.57 versus 6.62±0.64 kPa (54.9±4.3 versus 49.8±4.8 mmHg), respectively). When arousals were triggered by increasing inspired CO2 level, the maximal oesophageal pressure swing was greater (19.4±4.0 versus 13.1±4.9 cmH2O) and the oesophageal pressure nadir before the arousals was lower (-5.1±4.7 versus -0.38±4.2 cmH2O) with trazodone. When arousals were induced by stepwise CPAP drops, the maximal oesophageal pressure swings before the arousals did not differ. Trazodone at 100 mg increased the effort-related arousal threshold in response to hypercapnia in obstructive sleep apnoea patients and allowed them to tolerate higher CO2 levels. ER -