ADHD therapy to be applied transdermally

"The methylphenidate patch offers an option to children who have trouble swallowing oral medication," said Julie A. Dopheide, Pharm.D., BCPP, associate professor of clinical pharmacy in psychiatry and behavioral sciences at USC Schools of Pharmacy and Medicine in Los Angeles. "In addition, the application and removal of the patch can be individualized, focusing treatment to situations when the child needs the most medication," she explained. "This can minimize the total daily dose of stimulant, possibly minimizing adverse effects such as anorexia and growth effects."

According to the manufacturer, Daytrana should be removed nine hours after applied; however, it may be taken off earlier if a shorter duration is desired or the patient develops late-day side effects. Plasma concentrations of methylphenidate (MPH) start to decline after the patch is removed, although absorption may continue for several hours. Individualization of wear time may help manage some of the side effects associated with the drug.

In fact, Daytrana's prescribing information says that its use may lead to sensitization to MPH. Erythema is common at the site of application. However, when it is accompanied by edema, papules, vesicles, or does not improve within 48 hours or spreads beyond the patch site, it could be evidence of contact dermatitis and sensitization. In one study, 13.5% of patients became sensitized to Daytrana following continuous exposure to the patch at the same application site for three weeks. Shire states, however, that when the application sites were rotated daily, no cases of sensitization were reported. The company warns that patients who require oral MPH after developing sensitization to Daytrana should be closely monitored when beginning oral therapy. It is possible that a child may not be able to take MPH of any form following sensitization to the patch.

"Each person with ADHD has individual comorbidities, symptom severity, and side-effect vulnerability," said Dopheide. "Having different drug delivery options allows clinicians to better individualize treatment to improve functioning and drug tolerability."

According to Shire, Daytrana will be available in pharmacies beginning in mid-2006, in four strengths: 10, 15, 20, and 30 mg/nine hrs. The company suggests that the patch be used as part of a total treatment program for ADHD that may include psychological, educational, and social measures.

TIPS TO REMEMBER Daytrana