Public Health Advisory for Adderall and Adderall XR
Health Canada, the Canadian drug regulatory agency, has suspended the sale of Adderall XR in the Canadian market. Adderall XR is a controlled release amphetamine used to treat patients with Attention Deficit Hyperactivity Disorder (ADHD). The Canadian action was based on U.S. post-marketing reports of sudden deaths in pediatric patients.
Adderall XR is approved in the United States for the treatment of adults and pediatric patients 6 years of age and older with ADHD, and Adderall, the immediate-release formulation of the drug, is approved for pediatric patients with ADHD. The Food and Drug Administration (FDA) has been aware of these post-marketing cases, and evaluated the risk of sudden death with Adderall prior to approving the drug for treatment of ADHD in adults last year.
Of 12 total cases, five occurred in patients with underlying structural heart defects (abnormal arteries or valves, abnormally thickened walls, etc.), all conditions that increase the risk for sudden death. Several of the remaining cases presented problems of interpretation, including a family history of ventricular tachycardia, association of death with heat exhaustion, dehydration and near-drowning, very rigorous exercise, fatty liver, heart attack, and type 1 diabetes mellitus. One case was reported three to four years after the event and another had above-toxic blood levels of amphetamine. The duration of treatment varied from one day to 8 years. The number of cases of sudden deaths reported for Adderall is only slightly greater, per million prescriptions, than the number reported for methylphenidate products, which are also commonly used to treat pediatric patients with ADHD.
The FDA is continuing to evaluate these and other post-marketing reports of serious adverse events in children, adolescents, and adults being treated with Adderall and related products. When one considers the rate of sudden death in pediatric patients treated with Adderall products based on the approximately 30 million prescriptions written between 1999 and 2003 (the period of time in which these deaths occurred), it does not appear that the number of deaths reported is greater than the number of sudden deaths that would be expected to occur in this population without treatment. For this reason, the FDA has not decided to take any further regulatory action at this time. However, because it appeared that patients with underlying heart defects might be at increased risk for sudden death, the labeling for Adderall XR was changed in August 2004 to include a warning that these patients might be at particular risk, and that these patients should ordinarily not be treated with Adderall products.