The New England Journal of Medicine has published the results of an analysis that aimed to assess the cardiovascular risks posed by drugs used for the treatment of attention deficit–hyperactivity disorder (ADHD).
Adverse event reporting in North America has raised some concerns so a retrospective cohort analysis involving data for 1,200,438 children and young adults between the ages of 2 and 24 years from four managed health systems was conducted. This cohort provided 2,579,104 person-years of data which included 373,667 years of data for current users of ADHD drugs. The mean length of follow up was 2.1 years.
When compared to non users of ADHD drugs the rate of serious cardiovascular events was not statistically different for current users (hazard ratio 0.75, 95% CI 0.31-1.85) or former users (HR 1.03, 95% CI 0.57-1.89). There was also no difference in the rates of the individual end points of sudden cardiac death, acute myocardial infarction or stroke.
The authors do note however that the low number of events in the cohort means that the results are of limited statistical power. A further limitation relates to the sparse data for use over longer durations.
The authors therefore conclude that, "the point estimates of the relative risks for ADHD drugs did not indicate increased risk" but "a doubling in the risk could not be ruled out".
Action: Clinicians who prescribe medication for ADHD should be aware of this analysis. The results are reassuring but more research is needed to confirm long term safety.