Cardiovascular Effects of Methylphenidate, Amphetamines and Atomoxetine in the Treatment of Attention-Deficit Hyperactivity Disorder

Attention-deficit hyperactivity disorder (ADHD) is a very common condition in children and often extends into the adult years. Drugs such as methylphenidate, amphetamines and atomoxetine are frequently prescribed as part of management. The use of these drugs has been increasing and significant clinical benefit is achieved but safety has been questioned. In this review, the cardiovascular safety of these drugs is examined with regard to effects on blood pressure (BP), heart rate (HR), ECG parameters and the risk of sudden death. Methylphenidate appears to cause minor increases in BP and HR. There are no strong data to suggest that methylphenidate increases the corrected QT interval (QTc). Amphetamines appear to cause minor increases in HR and BP over the long term. There is growing evidence to suggest that amphetamines do not cause statistically or clinically significant increases in QTc. Sudden death remains an extremely rare event and there is no clear evidence to attribute this to methylphenidate. Some data even suggest that the risk of sudden death in treated children may be less common than in the background population. Limited data suggest that atomoxetine may increase BP and HR in the short term; in the long term it appears to increase BP. The effects of atomoxetine on QTc remain uncertain. Use of this drug does not appear to be associated with sudden death. Because the current evidence is based on research that has not been specifically designed to investigate the cardiovascular effects of these drugs it is difficult to draw firm conclusions, and further work is required specifically to address these questions.