The agencies will collaborate in what they’re calling ‘the most comprehensive study to date’ of the potential for increased risk of heart attack, stroke or other cardiovascular problems associated with the widely used ADHD meds.

Researchers supported by the Agency for Healthcare Research and Quality and the FDA will examine the clinical data of about 500,000 children and adults. The move comes after the FDA last February issued warnings about cardiovascular and psychiatric side effects associated with Adderall, Strattera, Ritalin and Concerta, among others.

ADHD meds can increase heart rate and blood pressure, prompting concerns increased cardiac risks. Moreover, the risks may be different for adults and children, but more evidence is needed about the long-term effects, according to a statement from the agencies. The analysis will take two years to complete.

Here’s some interesting ADHD scrip data, courtesy of Medco: Adults between 20 and 44 years old were the fastest-growing category getting a scrip between 2001 and 2006, up 114.2. Last year approximately 1.2 percent of the population of that age group filled a prescription for ADHD drugs.

The greatest use is among boys 10 to 19 years old, with 7.8 percent getting a scrip in 2006, up 37 percent from 2001 to 2006. About 6 percent of boys younger than 19 received ADHD drugs last year. Only 3.5 percent of girls ages 10 to 19 filled scrips in 2006, but as a group there was 74 percent growth in this category from 2001 to 2006. When boys and girls are factored into ADHD drug use, about 4.3 percent of all people aged 0-19 received ADHD drugs last year, up 41.4 percent from 2001-2006.

The planned analysis follows an FDA-sponsored preliminary study that compiled information from large health care databases on prescription drug use, inpatient care, outpatient treatment, and health outcomes, including death. Based on that effort, researchers identified people who took ADHD drugs during a seven-year period ending in 2005. AHRQ, which sponsors research on clinical effectiveness and safety, will team with FDA to complete the analysis of the data.

“This study highlights one of AHRQ’s most important missions: to collect and analyze, scientific evidence that will help patients, policymakers, and clinicians make the best possible decisions,” says AHRQ director Carolyn Clancy. “This partnership with the FDA is a great way to move closer to answering important clinical questions that affect children and adults who have ADHD.”

“Case reports have described adverse cardiovascular events in adult and pediatric patients with certain underlying risk factors who receive drug treatment for ADHD, but it is unknown whether or not these events are causally related to treatment,” says Gerald Dal Pan, who directs the FDA’s Office of Surveillance and Epidemiology. “The goal of this study is to develop better information on this question.”

The study will be coordinated by Vanderbilt University researchers on contract through AHRQ’s Effective Health Care program. Data analysis will be performed by researchers at Vanderbilt, Kaiser Permanente of California, the HMO Research Network and i3 Drug Safety, as well as from FDA and AHRQ. The analysis will include all drugs currently marketed for treating ADHD. The study will analyze the risks of all the drugs as a whole, and risks of the drugs grouped by class.

As the agencies note, Medicaid, Medicare, and the State Children’s Health Insurance Program will be interested in the results, since they provide reimbursement for ADHD pills. And the info could also be used for product labeling. According to the National Institute of Mental Health, ADHD affects approximately 3 percent to 5 percent of school-age children and about 4 percent of adults.

Use of ADHD drugs has increased in recent years among children and adults. A recent AHRQ analysis of medication expenditures found three ADHD drugs - Concerta, Strattera, and Adderall - ranked among the top five drugs prescribed for children ages 17 years and younger. About $1.3 billion was spent on those drugs in 2004, the study estimated. Adult use is also believed to be increasing.

In May 2006, based on a review of anecdotal reports of heart attack, stroke and sudden death among patients taking usual doses of ADHD medications, the FDA asked drugmakers to revise product labeling to reflect concerns about possible adverse events. Drugmakers have created patient Medication Guides for individual products to help patients understand risks.