Objective: In a 4-week, double-blind, placebo-controlled study, the attention-promoting agent modafinil improved symptoms of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents and was well tolerated. To assess the continued efficacy of modafinil and obtain additional safety data, an 8-week, open-label study was conducted as an extension to the double-blind study.
Method: Two hundred and twenty children and young adolescents (age range, 6-14 years) with ADHD who had completed 4 weeks of the double-blind period or had withdrawn for reasons other than an adverse event were enrolled. Patients received individually titrated doses of modafinil (100-400 mg), administered once daily or as a divided dose. Patients visited the clinic at open-label weeks 2, 4, and 8 for assessments of efficacy. Efficacy was assessed using the parent- or clinician-completed ADHD Rating Scale-IV (ADHD-RS-IV) Home Version, the parent-completed Conners' ADHD/DSM-IV Scale Parent Version (CADS-P), and the clinician-rated Clinical Global Impression of Improvement (CGI-I) scale. Adverse events were monitored.
Results: Modafinil improved symptoms on all ADHD rating scales and subscales during the open-label extension. Mean change (baseline to final visit) in Total score on the ADHD-RS-IV was -14.6 (95% CI: -16.40 to -12.70); and -7.6 (95% CI: -8.65 to -6.62) and -6.9 (95% CI: -7.90 to -5.94) in the Inattention and Hyperactivity-impulsivity scores, respectively. The mean Total score [SD] on the CADS-P decreased from baseline (74.4 [10.3]) to the final visit (63.2 [13.1]) (change: -11.2, 95% CI: -13.08 to -9.65). Fifty-three percent of patients were rated as much or very much improved on the CGI-I. Insomnia (13%) and headache (10%) were the most common adverse events. No clinically meaningful changes were observed in physical examination findings, electrocardiography, blood pressure, pulse, or body temperature. Clinically significant changes (increase or decrease) in body weight of 7% or more were observed for 30 patients (14%), with decreases (mean, 3.2 kg) reported for 22 patients (10%) and increases (mean, 3.7 kg) reported for eight patients (4%).
Conclusion: Modafinil remained efficacious and well tolerated in children with ADHD, improving ADHD symptoms and overall clinical condition during the open-label study. Limitations of the study include open-label dosing and lack of a placebo control.