A 41-year-old woman (BMI, 34 kg/m2) was referred with complaints of excessive daytime sleepiness, morning headaches, reduced energy during the day, nocturia, snoring, and witnessed apneas. Her Epworth sleepiness score was increased (13/24). There was no history or physical findings suggestive of heart or neurologic disease. Her other medical issues included chronic back and left knee pain. She had undergone numerous surgical procedures for these problems and now was receiving high doses of analgesics for pain control. Medications included methadone (20 mg twice daily) with an extra 10-mg dose at noon, and a combination medication consisting of oxycodone, 7.5 mg, acetaminophen, 325 mg, lamotrigine, 200 mg once daily, and piroxicam, 40 mg once daily (Percocet; Endo Pharmaceuticals; Chadds Ford, PA). The results of the sleep study were within normal limits during the first portion of the night. While the patient’s overall AHI was 15.5 events per hour; all events except two hypopneas occurred after 3:00 am (Fig 1
). It was noted by the sleep technician that the patient took two pills of the prescribed combination medication (Percocet; Endo Pharmaceuticals) at 2:00 am. After ingestion of the opioid, the patient experienced 92 events, of which all but 1 were central apneas (Fig 2
). The central apnea index (CAI) was 27.6 events per hour after the ingestion of the oxycodone/acetaminophen combination (Table 1). The central events were associated with an increased total number of arousals but were not associated with changes in sleep pattern or oxygen saturation.