Source: DGNews  |  Posted 8 years ago

By Bruce Sylvester

SAN FRANCISCO, CA -- May 26, 2003 -- Once-daily Adderall XR is effective and well tolerated for the long-term treatment of attention deficit/hyperactivity disorder (ADHD) in adults, according to an interim analysis of 10-month data from an extension study.

The data were presented here on May 21st at the 156th Annual Meeting of the American Psychiatric Association.

"We were quite encouraged to see that, at this stage of the study, not only has Adderall therapy been safe and efficacious, but every patient showed improvement in core symptoms of the condition, with no evidence of an emerging drug tolerance," said presenter and investigator Richard Weisler, MD, psychiatric researcher at Duke University Medical School in Durham, North Carolina, United States. Dr. Weisler is also in private practice in Raleigh, North Carolina.

The investigators enrolled 223 adults with a mean age of 39.8 years who had participated in a 4-week, randomized, double-blind, placebo-controlled, forced-dose titration study of once-daily Adderall XR. During the initial study, the researchers titrated dosing to determine optimal therapeutic effects with minimum adverse events. All subjects met Diagnostic and Statistical Manual IV (DSM-IV) criteria for ADHD and had a history of the condition prior to age 7.

For the extension study, the investigators took monthly vital signs and adverse event reports. They collected electrocardiographic data and laboratory measures at months 3 and 6 and at 12-month end point. They assessed ongoing treatment efficacy each month using the 18-item ADHD Rating Scale (ADHD-RS) for adults.

The criteria for inclusion in the extension study included at least 1 week of treatment in the antecedent study; 21 of the subjects in the extension study met that criterion but had a time-gap in Adderall treatment prior to the beginning of the extension study.

Results of the extension study show that the 57 patients who had received placebo during the initial study had the greatest improvement in ADHD-RS scores from baseline to interim end point, with a mean change of -11.9 (P<0.001). Patients who took Adderall XR with interruption (n=21) during the initial study had significant improvement in ADHD-RS scores from baseline to end point, with a mean change of -7.6 (P=0.041), as did the 145 patients with no interruption (mean change -6.0; P<0.001).

The most common adverse events were dry mouth, reported by 42% of treated patients; anorexia (30%); insomnia (25%); and headache (21%).

"Every subject has shown ongoing improvement in symptoms at this 10-month point," Dr. Weisler added.

He also said that the incidence of commonly reported adverse events has dropped over time during the study.

The study was supported by Shire Pharmaceutical.

1. Biederman J, Lopez FA, Boellner SW, Chandler MC: Efficacy of a mixed amphetamine salts compound in adults with attention-deficit/hyperactivity disorder. Arch Gen Psych 2001; 58:775