0678 A Rare Case of Sodium Oxybates–Associated Central Sleep Apnea: First Known Use of Adaptive Servo Ventilation for Successful Therapy

Abstract Introduction Central sleep apnea (CSA) may occur as an adverse effect of sodium oxybates, a medication commonly used to treat narcolepsy with cataplexy. Management is challenging, as sodium oxybates remain essential for symptom control in many patients, yet untreated CSA poses substantial respiratory risk. We present a rare case of sodium-oxybate–associated CSA successfully treated with adaptive servo ventilation (ASV), representing, to our knowledge, the first documented use of ASV for this indication. Methods A 49-year-old woman with longstanding narcolepsy with cataplexy presented with worsening daytime sleepiness despite stable use of sodium oxybate. She had been receiving a very high dose prescribed by an outside provider (6.75 g twice nightly), exceeding the recommended maximum of 4.5 g twice nightly, and her dose was subsequently adjusted to 4.5 g twice nightly. An in-lab polysomnogram revealed moderate central sleep apnea (AHI 21; RDI 23) with predominantly central events. Because the patient did not wish to wean or discontinue sodium oxybate—reporting that it remained the only therapy that consistently improved her sleep and cataplexy—adaptive servo ventilation (ASV) titration was pursued as the next step in management. She had previously failed multiple stimulants, wake-promoting agents, and SSRIs due to either limited efficacy or intolerable side effects. Her BMI was 18 kg/m2, she was not taking any CNS depressant medications, and her echocardiogram demonstrated a normal ejection fraction. Results The patient tolerated ASV well. Final settings included an EPAP of 5 cm H₂O with a pressure support range of 3–15 cm H₂O and minimal leak. Her adherence was excellent, with more than 93% of nights exceeding four hours of use. Residual AHI improved to 4.6 events per hour, accompanied by noticeable improvement in daytime alertness. She continued sodium oxybate without any respiratory complications. Conclusion ASV may be an effective and well-tolerated therapy for sodium-oxybate–induced CSA in patients who must continue the medication. Sodium oxybate can induce CSA by acting on GABA-B receptors in the Kölliker–Fuse and pre-Bötzinger complex, suppressing respiratory drive and depressing hypoglossal motor output. This case highlights the successful use of ASV in treating CSA secondary to oxybates when the medication cannot be weaned or discontinued. Support (if any)