Cardiovascular Safety of Stimulant Use Re-Examined

Study Examines Cardiovascular Safety of Stimulants in Children and Adolescents

Researchers found an increased risk of cardiovascular events in the first nationwide cohort prospective study of stimulant use in children and adolescents.

The study, which included children born in Denmark between 1990 and 1999 (N= 714,258) and children within this group diagnosed with ADHD after the age of 5 (N=8300), looked at cardiovascular events that resulted in hospital contact for the child. Prescriptions included in the study were medications containing amphetamine, dexamphetamine, or methylphenidate. Daily doses and dosages were considered in the analysis.

Søren Dalsgaard, MD, PhD, and colleagues found an adjusted hazard ratio of 1.83 for increased risk of any cardiovascular event for stimulant users among the larger cohort. In children with ADHD, the hazard ratio increased to 2.34 for those who used stimulants versus those who did not. Unlike previous smaller studies, the researchers found increased risk even in patients without predisposing cardiovascular risk factors. Furthermore, they found a dose-response relationship, with higher doses associated with increased risks.

Although Dalsgaard and colleagues noted the cardiovascular events were relatively rare (only 111 in this study), they noted the importance of the findings. “Our study of a possible dose-response relationship suggests a complex, time- and dose-dependent interrelationship between cardiovascular adverse events and stimulant treatment and cardiovascular effects of discontinuation of stimulant treatment in children and adolescents with ADHD,” they explained. “Our findings may also be relevant for future revisions of the international treatment guidelines with regard to the use of high doses of methylphenidate, and regarding the recommendation of drug holidays.”

References:

Dalsgaard S, Kvist AP, Leckman JF, Nielsen HS, Simonsen M. Cardiovascular Safety of Stimulants in Children with Attention-Deficit/Hyperactivity Disorder: A Nationwide Prospective Cohort Study. J Child Adolesc Psychopharmacol. 2014 Jun 23. [Epub ahead of print]. Available at: http://online.liebertpub.com/doi/full/10.1089/cap.2014.0020.