BACKGROUND Atomoxetine hydrochloride, a selective norepinephrine reuptake inhibitor was FDA approved for patients with attention-deficit/hyperactivity disorder. Little is known about adverse drug reactions of atomoxetine following an overdose among children. The objective of our study was to evaluate the type of atomoxetine adverse drug reactions in relation to dose. METHODS We evaluated children exposed to atomoxetine reported to a poison center from January-December 2004. RESULTS Sixty-four cases met all inclusion criteria. Twenty-one patients had an adverse drug reaction (15 at dosage range 0.52-6.25 mg/kg): agitation, headache, erythema, rash, elevated blood pressure and heart rate, nausea, emesis, and lethargy. In 51 patients, weights were known: group 1 (n = 43) received higher than maximum recommended doses >1.4 mg/kg and group 2 (n = 8) received < or = 1.4 mg/kg. There were no differences in adverse drug reactions in group 1 versus 2. Eight patients were admitted to a healthcare facility and all were discharged without any sequelae. Hypertension occurred in 3 of 9 patients for whom blood pressure was recorded. CONCLUSIONS At the doses reported, adverse drug reactions did not correlate with atomoxetine dose. Hypertension may occur in some patients following atomoxetine overdose.