Modafinil as adjunct therapy for daytime sleepiness in obstructive sleep apnea - A 12-week, open-label study

Study objectives: The purpose of this 12-week study was to evaluate the efficacy and safety of adjunct modafinil to treat excessive sleepiness in patients with obstructive sleep apnea (OSA) who experience residual sleepiness despite regular nasal continuous positive airway pressure (nCPAP) use. Design: Twelve-week, open-label trial. Setting: Twenty-two centers in the United States. Patients: We studied 125 patients with moderate-to-severe OSA (ie, respiratory disturbance index greater than or equal to 15) before nCPAP therapy and residual daytime sleepiness (Epworth sleepiness scale [ESS] score greater than or equal to 10) despite effective and regular nCPAP therapy. Patients were studied after completing a 4-week, double-blind, placebo-controlled trial of nCPAP plus modafinil for the treatment of residual daytime sleepiness. Interventions and measurements: Patients received individually titrated doses of modafinil (200 to 400 mg qd). Sleepiness was assessed using the ESS, quality of life was evaluated using the Functional Outcomes of Sleep Questionnaire (FOSQ), and the overall clinical effect was indexed using the clinical global impression of change scale. Adverse events, nCPAP use, and vital sign measurements were also recorded. Results: The significant improvements in daytime wakefulness and sleep-related functional status observed with modafinil treatment during the 4-week, double-blind study were maintained throughout 12 weeks of open-label treatment: week 12 ESS, 7.8 (4.7) vs 14.4 (3.1) at double-blind baseline; week 12 FOSQ, 3.3 (0.6) vs 14.4 (2.7) at double-blind baseline (mean [SD]). The percentage of patients rated as clinically improved increased from 83% after 1 week to greater than or equal to 93% after 2 to 12 weeks of open-label treatment. Mean (SD) nCPAP use decreased from 6.3 (1.3) h/night at baseline to 5.9 (1.4) h/night (p = 0.004) during open-label treatment. The most common adverse events were headache (28%), anxiety (16%), and nervousness (14%). Conclusions: Modafinil remained effective and well tolerated as an adjunct therapy for residual daytime sleepiness even after 12 weeks of daily dosing in patients with OSA receiving nCPAP therapy.