Stimulants for kids with ADHD—how to proceed safely

Before prescribing stimulants to children or adolescents with ADHD, complete an in-depth cardiac history and physical examination, as recommended by the AHA and AAP (TABLE),^2,3 to identify conditions that increase the likelihood of SCD, such as hypertrophic cardiomyopathy (HCM), long QT interval syndrome (LQTS), and preexcitation syndromes such as Wolff-Parkinson-White syndrome (WPW).

Confirm, for instance, that your patient has a normal heart rate, rhythm, and BP, and no pathological murmurs. In a survey of families with a child or young adult who had sudden cardiac arrest, 72% reported the patient had at least one cardiovascular symptom within 19 to 71 months of SCD, and 27% reported having a family member with a history of SCD before age 50.¹² For patients with no such complaints or family history, the news is good. Two large studies found that in the absence of any suspected or overt cardiac disease, children with ADHD who were receiving stimulant therapy had no increased risk of SCD.^13,14

What about patients with this common heart problem? Physicians face a dilemma when a stimulant is needed and the patient has a common acyanotic congenital heart lesion, such as a small atrial or ventricular septal defect, which is considered nonlethal. Based on limited data, there is no evidence that the risk of SCD is higher when these patients take stimulants.¹⁵

Should you order that EKG—or not?

Currently, the AHA still favors an EKG, though in a correction to its original statement, it adjusted the language to say that EKG could be “useful,” in addition to an in-depth cardiac history and physical examination.¹⁶

Opposition to routine EKG screening in these patients stems from the procedure’s extremely low yield and relatively high false positive findings, which may result in higher financial and psychological burdens for patients and families. Thomas et al¹⁷ reported that at a single center, the number of EKGs ordered with an indication of “stimulant medication screening” quadrupled during 2009, the year after the AHA published its recommendations. Of 372 patients referred for EKG, 24 (6.4%) had abnormal findings and 18 were referred for further evaluation, but none were found to have cardiac disease. ADHD therapy was delayed in 6 patients because of the EKG.

In a similar evaluation of 1470 ADHD patients ages 21 years and younger, Mahle et al18 noted that 119 patients (8.1%) had an abnormal EKG, 78 of whom (65%) were already receiving stimulants. Five patients had cardiac disease, including 2 who had a preexcitation syndrome. Overall, the positive predictive value was low (4.2%).¹⁸ Other research, including a study lead by one of this article’s authors (SKM), has found similar increases in the number of EKGs ordered for patients with ADHD.¹⁹

Cost vs benefit. In the Mahle et al¹⁸ study described above, the mean cost of EKG screening, including further testing for patients with abnormal initial results, was $58 per child. The mean cost to identify a true-positive result was $17,162.¹⁸

Two large studies found no evidence to support an increased risk of SCD in children with ADHD who are receiving stimulant therapy in the absence of any suspected or overt cardiac disease.In 2012, Leslie et al²⁰ used simulation models to estimate the societal cost of routine EKG screening to prevent SCD in children with ADHD. Their findings: The cost would be high relative to its health benefits—approximately $91,000 to $204,000 per life year saved. Furthermore, these researchers found that ordering an EKG to screen for 3 common cardiac conditions linked to SCD (HCM, WPW, and LQTS) would add <2 days to a patient’s projected life expectancy.²⁰

Our recommendations

We believe stimulants can safely be used in the treatment of children and adolescents with ADHD, given the evidence that suggests a low risk of SCD. That said, it is prudent to avoid prescribing stimulants for children who have an underlying condition that may deteriorate secondary to increased blood pressure or heart rate.

We agree with the current AHA and AAP recommendations that physicians should obtain an in-depth cardiac history and physical examination, with emphasis on screening for cardiac disorders that may put a child at risk for SCD, such as HCM, LQTS, and preexcitation syndromes. For instance, a history of a family member with palpitations should prompt an EKG, which may reveal familial preexcitation syndrome. Similarly, an EKG is in order if you suspect LQTS based on a parent’s description of a family member’s death after hearing a loud noise, such as fireworks.

A story of a patient's grandfather who died while taking a drug linked to QT prolongation prompted an EKG and the discovery that the child had LQTS.It often takes active probing to uncover a history of sudden death in the family that a parent may not consider relevant. For example, one of the authors (SKM) cared for a 6-year-old boy who presented with a history of syncope after his hand got caught in a door jam. On further probing, his mother revealed that her father had died at age 30 while he was taking astemizole, an allergy drug known to prolong the QT interval. Subsequent EKGs revealed that both the boy and his mother had LQTS.