Temazepam 10mg does not affect breathing and gas exchange in patients with severe normocapnic COPD☆

Summary 

Background

Benzodiazepines can improve sleep quality, but are also thought to cause respiratory depression in patients with chronic obstructive pulmonary disease (COPD). The aims of this study were to assess the effects of temazepam on indices of circadian respiratory function, dyspnea, sleep quality, and sleepiness in patients with severe COPD and insomnia.

Methods

In a double-blind, randomized, placebo-controlled, cross-over study in 14 stable patients with COPD (mean FEV₁ 0.99±0.3L) with insomnia, polysomnography with continuous transcutaneous capnography and oximetry, arterial gas sampling, hypercapnic ventilatory response, multiple sleep latency test, Epworth Sleepiness Scale, dyspnea and sleep visual analogue scales (VAS) were performed at baseline, after one week of temazepam 10mg at bedtime and after one week of placebo.

Results

Temazepam did not cause statistically significant changes in mean transcutaneous carbon dioxide tension during sleep compared to placebo (5.9±1.0kPa vs. 6.3±1.4kPa, p-value 0.27), nor in mean oxygen saturation (92±3% vs. 92±2%, p-value 0.31), nor in any of the other investigated variables, except for the total sleep time and sleep latency VAS, which improved with temazepam.

Conclusions

One week usage of temazepam 10mg does not influence circadian respiratory function, dyspnea, and sleepiness in patients with stable, severe, normocapnic COPD and insomnia and it improves total sleep time and subjective sleep latency. However, this is a preliminary explorative study for assessing the feasibility to perform a larger study on this topic. The clinical implications of this study are very limited.

Keywords: Benzodiazepines, Chronic Obstructive Pulmonary Disease, Gas exchange, Insomnia, Sleep, Temazepam

Abbreviation list: ABG, arterial blood gas, AHI, apnea–hypopnea-index, COPD, chronic obstructive pulmonary disease, DI, desaturation index, HCVR, hypercapnic ventilatory response, HR, heart rate, PaCO₂, arterial partial pressure of carbon dioxide, PaO₂, arterial partial pressure of oxygen, PetCO₂, end-tidal partial pressure of carbon dioxide, PtcCO₂, transcutaneous partial pressure of carbon dioxide, PSG, polysomnography, REM, rapid eye movements, SaO₂, arterial saturation of oxygen, SpO₂, functional saturation of oxygen, TST, total sleep time, VAS, visual analogue scale