Obstructive sleep apnea (OSA) patients using CPAP (Continuous Positive Airway Pressure) are frequently prescribed BZRA(Benzodiazepine receptor agonist) hypnotics. However, no prior studies have evaluated the effect of BZRAs on the efficacy of CPAP. CPAP works as a pneumatic splint so upper airway muscle tone is much reduced. Therefore, further reduction in muscle tone by BZRAs should be minimal. For this reason, we hypothesize that Zolpidem (selective BZRA with greater hypnotic than muscle relaxant properties)should not cause a change in the level of required CPAP to maintain an open airway.
To test this hypothesis, we conducted a double blind placebo controlled cross-over study in patients with OSA currently being treated with CPAP. Patients were studied on three nights in the sleep laboratory over three consecutive weeks (one night per week). On night one, the pressure level required to prevent apnea, hypopnea, and snoring was determined (optimal pressure). On the second night and third nights, either Placebo or Zolpidem 10 mg was given and subjects slept on the CPAP level determined by first night (optimal pressure).
For our initial four patients, there was no significant difference in Total Sleep Time (TST), REM sleep, AHI overall, or AHI NREM sleep (see table).
Study of a limited number of OSA patients suggests Zolpidem 10 mg does not significantly increase the AHI in a patient treated with an appropriate level of CPAP. We plan to study at least 20 patients to confirm this preliminary result.
If further study confirms our preliminary findings this would suggests Zolpidem can be used safely in OSA patients with insomnia who are on CPAP. This may improve tolerance of CPAP in these patients.
Prakash Patel, None.