Screen ADHD kids for heart problems

New guidelines urge docs to do ECG before writing stimulant scripts

By Gillian Woodford

New guidelines from the American Heart Association (AHA) urge physicians to screen all kids for cardiac problems before prescribing stimulants for attention deficit hyperactivity disorder (ADHD).

The recommendations, published online ahead of print April 21 in Circulation, further strengthen warnings already listed on the drugs' labels. "We're trying to give the physicians who diagnose ADHD a roadmap," guideline author Dr Catherine Webb, of the Children's Memorial Hospital in Chicago, told NRM. "[Lead author] Dr Victoria Vetter and I are both pediatric cardiologists and we have a lot of patients with ADHD who've been denied these meds." Dr Webb hopes the recommendations will help patients get the help they need, safely. "Parents have been so nervous since the black box warning and the children aren't happy being this way."

The stimulants used to treat ADHD, mainly amphetamines and methylphenidate, are well known to cause increased heart rate and blood pressure and have been linked to several sudden cardiac deaths in children in the US. The guidelines note that a higher prevalence (between 33 and 42%) of ADHD in kids with pre-existing heart conditions, possibly due to chronic or intermittent hypoxia, has been found in several studies.

CANADIAN CHARGE
Between five and 10% of kids in Canada suffer from ADHD, with around two million prescriptions for ADHD meds written each year. More and more adults are also taking these drugs as 'adult ADHD' becomes more accepted.

Canada has led the charge to strengthen labelling and warnings about ADHD drugs. In 2005, Health Canada temporarily pulled the amphetamine Adderall following an FDA post-marketing report on 20 sudden deaths in kids taking the drug. Adderall's ban was lifted a few months later, but only after strong warnings were added to it and other ADHD meds. The AHA guidelines include a nod to Canada's swift action.

However, Canadian organizations haven't issued recommendations similar to the AHA's. The Canadian Heart and Stroke Foundation and the Canadian Paediatrics Society declined to comment for this article.

RISKY BUSINESS
Dr Steve Nissen, the Cleveland Clinic cardiologist who blew the lid off the diabetes drug rosiglitazone's heart risks last year, was part of a 2006 FDA panel that made the surprise move to add a 'black box' warning about CVD risk to ADHD meds. Dr Nissen is pleased with the new guidelines. "I think this a very reasonable and prudent set of recommendations," he told NRM. "Although the risks of catastrophic complications are small, the consequences can be serious or fatal. Sudden death in a child is such a grave and tragic event that I believe we must do everything possible to avoid this outcome."

Dr Nissen also believes we're prescribing too many of these meds, considering the unknown risks. "We learned at the FDA panel that up to 10% of boys, ages 10 to 11, take ADHD drugs. It seems excessive to treat so many children in this fashion and I worry about the longterm consequences."

He adds that with more and more adults on these meds, adverse events are bound to grow. "Adults are likely more vulnerable to the potential adverse effects of stimulant drugs, particularly older adults," he says. "We learned that at least 150,000 adults over the age of 50 take ADHD drugs. Such individuals have a higher underlying risk of heart attack, stroke and sudden death. Safety studies in adults are urgently needed."