The purpose of this study was to evaluate how the first oral administration of suvorexant affects PSG results in patients with severe obstructive sleep apnea (OSA). Single-center, prospective study conducted in a nonrandomized, uncontrolled, unblinded fashion. Undiagnosed 64 patients with suspected OSA underwent first-night PSG, and 30 patients with severe OSA (Apnea Hypopnea Index [AHI] ≥ 30 events/h) underwent second-night PSG testing after administration of 15 mg suvorexant. The change in AHI between the first and second nights was not significant, although the upper limit of the 95% confidence interval for the mean difference in AHI was high at 5.987.The mean duration of apnea on the second night was significantly prolonged compared to that on the first night, but there were no significant differences n 3% oxygen desaturation index, saturation of percutaneous oxygen<90% time. On the second night, total sleep time was significantly prolonged, mid-night awakenings decreased, REM sleep percentage increased, and REM latency was shorter. Because the environment for PSG testing is very different from the patient's home and many patients have difficulty sleeping, there are clinical cases in which PSG is performed with sleep medication. In this study, PSG after oral administration of 15 mg of suvorexant on the second night showed no significant difference or clear trend in AHI. However, the upper limit of the 95% confidence interval for the mean difference in AHI was greater than 5, suggesting that suvorexant may exacerbate AHI, even with the first administration.
