EFFECTS OF ZOLPIDEM AND TRIAZOLAM ON SLEEP AND RESPIRATION IN MILD-TO-MODERATE CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

Sleep problems and nocturnal arterial oxygen desaturation are common i n patients with chronic obstructive pulmonary disease (COPD). Hence, t he safety and efficacy of new hypnotic agents must be ascertained in t his group of patients. We performed a double-blind, randomized, single -dose, placebo and active drug controlled, crossover study in 24 patie nts with insomnia (subjective sleep latency > 30 minutes and sleep dur ation 4-6 hours) and mild to moderate COPD (mean FEV1 61 +/- 12(SD)% p redicted) in order to establish the effects of zolpidem 5 mg and 10 mg on sleep and respiration and to compare these effects with triazolam 0.25 mg. Arterial oxygen saturation for the entire night, by hour and by stage, and the apnea-hypopnea index for the entire night were not s ignificantly different with placebo and the var-ious drug conditions. Total sleep time and sleep efficiency were increased over placebo by a ll three drug conditions. Triazolam was more effective than zolpidem 5 mg but not zolpidem 10 mg, and there was no significant difference be tween zolpidem 5 mg and zolpidem 10 mg. Zolpidem 10 mg and triazolam b oth reduced the number of awakenings (> 15 seconds duration) per hour of sleep. Although there was a trend for triazolam to be more efficaci ous than zolpidem 10 mg, no statistically significant difference was f ound for any objective or subjective sleep variable. Likewise, zolpide m 10 mg tended to be more efficacious than zolpidem 5 mg, but the diff erence was only significant in terms of perceived sleep quality and ea se of falling asleep. In patients with mild to moderate COPD without s evere awake resting hypoxemia or hypercapnia, zolpidem and triazolam i n suggested therapeutic doses are safe (with respect to respiration) a nd effective hypnotics. Zolpidem 10 mg is similar in its hypnotic effe ct to triazolam 0.25 mg. However, possible individual adverse effects suggest that caution is still required when these hypnotics are prescr ibed to these patients. Additional caution must be exercised because t his study evaluated only a single night of treatment with each dose of sedative, but usually hypnotics are prescribed for more than one nigh t.