Atomoxetine use during a period of FDA actions.

CONTEXT: The Food and Drug Administration (FDA) issued a Public Health Advisory entitled "Suicidal Thinking in Children and Adolescents Being Treated with Strattera (Atomoxetine)" on September 29, 2005. At FDA's request, the manufacturer subsequently added a boxed warning to the drug's labeling on November 8, 2005.

OBJECTIVE: To evaluate whether the boxed warning for suicidal thinking in atomoxetine's labeling was associated with a change in the pattern of attention-deficit/hyperactivity disorder (ADHD) medication use.

METHODS: Patients who had an ADHD diagnosis and were prescribed either atomoxetine or stimulants between January 2004 and December 2007 were selected from IMS LifeLink Health Plan Claims database. In this ecologic analysis, the outcome measure is the incident atomoxetine use rate, defined as the proportion of atomoxetine incident users among all initial ADHD pharmacotherapy users. The impact of the boxed warning was evaluated using interrupted time series analysis.

RESULTS: A total of 16,311 patients met the definition of incident ADHD medication users. The incident atomoxetine use rate decreased from January 2004 to September 2005 among all age groups (range, -0.45% to -0.74%); and the rate among adult patients decreased by 11.89% (95% confidence interval, 3.05%-20.74%) from September 2005 to November 2005. No long-term impact was detected.

CONCLUSIONS: Significant decline of the atomoxetine use rate was observed before the boxed warning in all age groups. No significant change was detected in the atomoxetine use rate among targeted children or adolescents after the FDA's boxed warning concerning suicidal thinking.