Effect of two different methods of initiating atomoxetine on the adverse event profile of atomoxetine.

OBJECTIVE

To compare the effects of two different methods for initiating atomoxetine in terms of the incidence of early adverse events.

METHOD: Data on atomoxetine treatment-emergent adverse events in youths, ages 6 to 18 years, were analyzed from five randomized, double-blind, placebo-controlled, acute-phase studies. Two studies involve once-daily dosing and titration to 1.2 mg/kg/day over 3 days (fast/once daily, n = 234) and three involve twice-daily dosing and titration to a dose of 1.2 mg/kg/day over at least 2 weeks (slow/twice daily, n = 213).

RESULTS

During the first 2 weeks of treatment, fast/once daily titration patients showed higher rates of spontaneously reported adverse events than patients in the slow/twice daily titration group. This included decreased appetite (14.3% versus 8.0%, p = .036) and somnolence (14.3% versus 4.2%, p < .001). Patients in the slow/twice daily group showed higher rates of headache (7.4% versus 16.9%, p = .003). Analysis of the studies' overall acute treatment phases revealed significantly higher rates in the fast/once daily group only for somnolence. No significant differences were seen in completion rates or reasons for discontinuation.

CONCLUSIONS

When starting atomoxetine, the risk of adverse events within the first few weeks of treatment may be lower if patients are dosed twice daily and titrated to the 1.2 mg/kg/day total daily dose over the first week.