Long-term safety and effectiveness of mixed amphetamine salts extended release in adults with ADHD

Objective: Assess the long-term safety and effectiveness of mixed amphetamine salts extended release (MAS XR) in adults with attention-deficit/ hyperactivity disorder (ADHD) combined subtype. Methods: A 24-month, open-label extension of a 4-week, multicenter, double-blind, placebo-controlled, parallel-group, forced-dose-escalation study of MAS XR in adults (≥ 18 years of age) with ADHD. The 223 enrolled subjects started treatment at 20 mg/day for 1 week, with subsequent titration up to 60 mg/day for optimal therapeutic effects. At monthly visits, efficacy was assessed based on the ADHD Rating Scale IV (ADHD-RS-IV). Safety assessments included spontaneously reported adverse events, laboratory assessments, and monitoring of vital signs. Findings: ADHD symptoms significantly improved for all subjects as measured by change from baseline in mean ADHD-RS-IV total scores (-7.2 ± 13.04 unit points; P < .001); this was sustained for up to 24 months. The most common treatment-related adverse events were dry mouth (43% of subjects reporting at least one occurrence), infection (33%), insomnia (32%), anorexia/decreased appetite (32%), headache (30%), and nervousness (26%). Most adverse events were mild to moderate in intensity. Conclusion: Treatment with MAS XR 20-60 mg/day for adult ADHD was generally well tolerated and was associated with sustained symptomatic improvement for up to 24 months.