The combination of atomoxetine and oxybutynin for the treatment of obstructive sleep apnea in children with Down syndrome

Study Objectives: Children with Down syndrome (DS) are at very high risk for obstructive sleep apnea (OSA). Current OSA treatments have limited effectiveness in this population. We evaluated the effectiveness of atomoxetine and oxybutynin (ato-oxy) to treat OSA in children with Down syndrome. Methods: Children ages 6-7 years old with Down syndrome and OSA participated in a double-blind crossover clinical trial evaluating two dose regimens of ato-oxy. Participants received low-dose ato-oxy (0.5 mg/kg atomoxetine and 5mg oxybutynin) and high-dose ato-oxy (1.2 mg/kg atomoxetine and 5mg oxybutynin) for 1 month in random order. The primary study outcome was change in obstructive apnea-hypopnea index. Health-related quality of life as measured by the OSA-18 as well as changes in sleep architecture were secondary outcomes. Results: Fifteen participants qualified for randomization and 11 participants had complete data at all points. Baseline obstructive apnea-hypopnea index was 7.4 +/- 3.7 (mean +/- standard deviation), obstructive apnea-hypopnea index with low-dose ato-oxy was 3.6 +/- 3.3 (P =.001 vs baseline), and obstructive apnea-hypopnea index with high-dose ato-oxy was 3.9 +/- 2.8 (P =.003 vs baseline). No significant sleep architecture differences were present with ato-oxy. No significant difference in OSA-18 score was present. OSA-18 total score was 51 +/- 19 at baseline, 45 +/- 17 (P =.09) at the end of 4 weeks of low-dose ato-oxy, and 45 +/- 16 (P =.37) at the end of high-dose ato-oxy therapy. The most common adverse effects were irritability and fatigue, and these were generally mild. Conclusions: Ato-oxy is a promising treatment for OSA in children with Down syndrome.