New ADHD drugs reduce likelihood of abuse

By Karla Gale

NEW YORK (Reuters Health) - Two new formulations of drugs traditionally used to treat attention deficit/hyperactivity disorder (ADHD), methylphenidate and d-amphetamine, last longer and have less potential for abuse, according to presentations at the American Psychiatric Association annual meeting in San Diego.

"Daytrana and Vyvanse are new options that address the limitations of medications previously available to treat ADHD," Dr. Robert L. Findling, from Case Western Reserve University in Cleveland, told Reuters Health.

Findling presented his teams' research findings on the drugs, both marketed by Shire US Inc., and approved by the US Food and Drug Administration.

Daytrana delivers methylphenidate through a skin patch with the dosage controlled by the patch size and by the duration of wear. "One advantage of the patch, first and foremost, is its flexibility," Findling said.

"Kids have no difficulty using the patch," he added, and it has been formulated so it can't be re-used. "That way, they can't stick it on a buddy" when they're horsing around, he added.

Findling's team compared the patch with oral methylphenidate and placebo in 270 patients ages 6 to 12 years old. The study included a 5-week initial treatment phase, followed by a 2-week maintenance phase, and a 30-day follow-up period.

Using an ADHD rating scale, scores with both forms of the drug improved ADHD symptoms compared with placebo; and both were equally effective, according to the investigators.

Findling and associates also presented the trial results for Vyvanse (lisdexamfetamine dimesylate), a drug associated with d-amphetamine. It offers the advantage of extended duration consistently delivered throughout the day, with a reduced potential for abuse, overdose toxicity and drug tampering, the investigators reported.

They investigated the long-term efficacy, safety, and tolerability in patients between 6 and 12 years old. The optimum dose was 30 to 70 milligrams per day.

At the end of the 12-month trial, treatment resulted in a 60-percent improvement in ADHD scores. Using another rating scale, 95 percent of subjects were considered "much improved" or "very much improved" at 12 months.

For both drugs, adverse effects were mostly mild-to-moderate, similar to those of the parent drugs, d-amphetamine and methylphenidate, the presenters noted.