Evaluation of dystonia in children and adolescents treated with atomoxetine within the Truven MarketScan database: a retrospective cohort study

ABSTRACT

Objective: Atomoxetine is a non-stimulant drug indicated for the treatment of attention-deficit/hyperactivity disorder in children aged ≥6 years, adolescents, and adults. In this retrospective cohort study, the incidence and risk of dystonia in children and adolescents treated with atomoxetine was compared to a propensity score-matched cohort of stimulant users.

Methods: Data between 1 January 2006 and 31 December 2014 from patients aged 6–17 years in the Truven Health Analytics MarketScan database were used to generate two cohorts of patients: (1) atomoxetine users and (2) stimulant (methylphenidates or amphetamines) users. A Cox proportional hazards regression model was used to compare incidence of dystonia across propensity score-matched cohorts.

Results: Of the 70,657 atomoxetine users, 70,655 users were propensity score-matched to a stimulant user. In the atomoxetine- and stimulant-treated cohorts, the crude incidence rates of dystonia were 54.9 (95% CI: 27.1–82.7) and 77.9 (95% CI: 49.1–106.8) per 100,000 person-years, respectively. The hazard ratio for occurrence of dystonia with atomoxetine use relative to stimulant use was 0.68 (95% CI: 0.36 − 1.28; P = 0.23).

Conclusion: In this large retrospective cohort study, there was no significant difference in incidence or risk of dystonia among patients treated with atomoxetine compared to stimulants.

KEYWORDS:

• Atomoxetine hydrochloride
• attention deficit disorder with hyperactivity
• dystonia
• retrospective studies
• cohort studies
• ADHD

Acknowledgments

Sriram Govindan, PhD, a full-time employee of Eli Lilly Services India Private Limited, provided medical writing assistance for this manuscript.

Declaration of interest

All the authors are employees of Eli Lilly and Company, Indianapolis, IN, USA and hold company stocks. The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This study was sponsored by Eli Lilly and Company, Indianapolis, IN 46285, USA.