Note: This report is greater than 5 years old. Findings may be used for research purposes but should not be considered current.
More than 1.5 million U.S. adults use stimulants and other medications labeled for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD). These agents are known to increase heart rate and blood pressure.
Using computerized health records from four study sites (Ingenix-3, Tennessee Medicaid, Kaiser Permanente California, and the HMO Research Network), we identified 150,658 adults aged 25-64 years with prescriptions for methylphenidate, amphetamines (and amphetamine salts) or atomoxetine at baseline. Each medication user was matched to two non- users on study site, birth year, gender and calendar year of cohort entry. Study endpoints were acute myocardial infarction (MI) and/or sudden cardiac death (SCD). Poisson regression was used to compare adjusted rates in users and non-users of ADHD medications.
During 844,615 person-years of follow-up, 1357 cases of MI and 296 cases of SCD occurred. We had 113,324 person years of current use (average 0.74 years per user), with a crude incidence of MI of 1.34 per 1000 person-years and of SCD of 0.30 per 1000. Multi-variable adjusted rate ratio of MI/SCD for current use vs. non-use of ADHD medications was 0.87 (95% CI 0.74-1.02). Adjusted rate ratios for current use of methylphenidate, amphetamines or atomoxetine vs. non-use of any ADHD medications were 0.85 (95% CI 0.68-1.07), 0.93 (95% CI 0.73-1.19), and 0.88 (95% CI 0.52-1.49), respectively. There was no evidence of increasing risk with increasing duration of use. The adjusted rate ratio for MI/SCD for current vs. remote use (> 1 year since last use) was 1.04 (95% CI 0.85-1.29). Results were similar when users were restricted to new users (no dispensing for ADHD medications in the year prior to cohort entry), when the cohort was restricted to those with or to those without evidence of prior cardiovascular disease, or when we restricted the cohort to those aged 25-44 years or 45-64 years during follow- up.
Our results do not support an association between the use of ADHD medications in young and middle-aged adults and the risk of MI or SCD.