In an attempt to lay to rest a long-standing and controversial concern, a new retrospective study has found no evidence of an increased risk of heart attack, stroke or sudden cardiac death associated with the use of attention deficit hyperactivity disorder, or ADHD, pills among young and middle-aged adults compared with those who do not or rarely take these meds.
The reason for undertaking the study has been a growing number of prescriptions for ADHD pills that are written for adults. The study authors noted that, according to a 2006 FDA advisory committee, meeting, more than 1.5 million US adults were taking the meds during the prior year and that adults received about 32 percent of all prescriptions written. But while placebo-controlled studies in children and adults indicted elevated blood pressure levels, which would be expected to increase the rate of cardiovascular events, clinical trials were not large enough to assess the risk.
The study, which was published online today by the Journal of the American Medical Association, analyzed using electronic health care records of more than 150,350 people from four study sites between 1986 and 2005 who used ADHD pills. Most took methylphenidate - otherwise known as Concerta and Ritalin, among other names - which accounted for 43 percent of total usage (here is the study).
The adults examined ranged in age from 25 to 64 years old. During follow-up, there were 1,357 cases of heart attacks, 296 cases of sudden cardiac death and 575 cases of stroke. Besides the top-line finding, the researchers write they also found "little support" for increased risk of any specific pill or longer duration of current use. The results were similar when restricted to new users. Rate ratios did not appear to be influenced by prior cardiovascular disease or prior non-ADHD psychiatric conditions.
In an accompanying editorial, Philip Shaw of the Human Genome Research Institute and formerly of the National Institute of Mental Health, wrote that the findings support the 2006 decision by the FDA not to place a Black Box warning about serious cardiovascular events on ADHD meds for all children and adults but to pursue further research.
"The findings, however, do not directly inform the current black box warning for psychostimulants, which is confined to patients with structural heart lesions. The study focused on very rare events, which prevented examination of specific subgroups such as individuals with cardiac disease. Joint care by cardiologists and other physicians remains necessary for these individuals," he cautions (read here).
He adds that the study does not provide support for the notion that routine electrocardiograms should be undertaken before treatment begins, although he cites a recommendation that referred to children and adolescents (see here).
heart attack pic thx to bart on flickr