Relative Cardiovascular Safety of Psychostimulants Used to Treat Attention-Deficit Hyperactivity Disorder

The pertinent literature was reviewed on cardiovascular changes induced by psychostimulant medication treatment of hyperactive children. An assessment of 15 controlled studies using test doses of methylphenidate revealed a significant elevation of the resting heart rate in previously unmedicated children (mean + 11 beats/min) but, with continued drug treatment, only a minor iǹsignificant increase (mean + 4 BPM) is observed. Methylphenidate resulted in no consistent or clinically meaningful blood pressure changes (8 studies) and no EKG irregularities (4 studies). Available data for dextroamphetamine and pemoline were less extensive, but showed essentially no significant cardiovascular changes in hyperactive youth. Stimulant overdoses in nonhyperactive children often led to hypertension and tachycardia, but were associated with only one cardiovascular fatality (amphetamine). Comparable studies of these stimulants in adults revealed: (1) tachycardia and hypertension following high test doses of methylphenidate, (2) hypertension but no tachycardia following high test doses of dextroamphetamine, (3) far greater cardiovascular changes following the parenteral administration of stimulants, (4) the development of a prominent degree of tolerance to the cardiovascular effects of stimulants with continued use, (5) very infrequent cardiovascular changes (3%) in medically ill, older adults following stimulant treatment for depression, and (6) infrequent cardiomyopathy and arteritis in association with amphetamine abuse, but not with pemoline or methylphenidate use. The stimulant-induced changes in children are modest in comparison with changes in cardiovascular functioning associated with normal daily activities, and are not comparable to the risks that can occur with tricyclic antidepressants. There appears to be a wide margin of cardiovascular safety when standard psychostimulants are taken orally in customary doses for long periods by hyperactive children. In view of the numerous negative studies, it probably is not essential to monitor heart rate, blood pressure, or EKG prior to or during routine psychostimulant treatment of children and adolescents with ADHD, unless there are comorbid cardiovascular abnormalities.