title: Clinical Impact of Not Achieving Recommended Dose on Duration of Atomoxetine Treatment in Adults with Attention-Deficit/Hyperactivity Disorder.
abstract: To compare atomoxetine (ATX) length of therapy (LoT) among adults with ADHD who reached the recommended dose of 80 mg/day (ATX ≥ 80) versus those who did not (ATX < 80) analyzed separately in patients prescribed ATX as monotherapy (mono) and in combination with other ADHD medications (combo).
  
  
  
  This was a retrospective observational cohort study of the Truven Health Marketscan Commercial Claims Database from January 1, 2006-September 30, 2013, with a 6-month preindex period free of ATX (1st ATX claim as index event) and a 1-year follow-up. LoT during follow-up was calculated using prescription claim fill dates and included all days with medication on hand regardless of treatment gaps.
  
  
  
  Only 45.0% of the 36,076 mono and 77.9% of the 1548 combo patients reached an ATX dose of ≥80 mg/day in 1-year follow-up. When patients filled at least one 80 mg prescription, their total days of therapy over the course of a year were significantly greater than if they did not (mono: 159.3 vs. 65.6 days; combo: 237.4 vs. 172.0; P < 0.0001). Across all timepoints examined (Day 14, 30, 60, 90, 210) for mono and combo, ATX ≥ 80 versus ATX < 80 patients had greater mean doses (P < 0.0001). Combo patients had longer ATX LoT than mono patients regardless if they reached 80 mg or not (P < 0.0001), but mono patients LoT was 93.8 days longer for ATX ≥ 80 versus ATX < 80 patients compared to 65.5 days for combo patients. Of patients reaching 80 mg/day, 71.7% of mono and 62.8% of combo patients did so by Day 30. For mono ATX ≥ 80 and ATX < 80 patients, LoT was significantly (P < 0.0001) less in previously treated patients compared to naive patients.
  
  
  
  Ensuring adult ADHD patients are treated with ATX at a target dose of 80 mg/day is an important clinical consideration for maximizing patient days on therapy, which can be important for treatment optimization.
authors.affiliation: Lilly USA LLC, Indianapolis, IN, USA.
authors.forename: David B
authors.initials: DB
authors.lastname: Clemow
authors.affiliation: Lilly USA LLC, Indianapolis, IN, USA.
authors.forename: Allen W
authors.initials: AW
authors.lastname: Nyhuis
authors.affiliation: Lilly USA LLC, Indianapolis, IN, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Robinson
mesh_terms: D000293:Adolescent; D018759:Adrenergic Uptake Inhibitors / Q000627:therapeutic use*; D000328:Adult; D000367:Age Factors; D000069445:Atomoxetine Hydrochloride / Q000627:therapeutic use*; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000453:epidemiology; D015331:Cohort Studies; D016208:Databases, Factual / Q000706:statistics & numerical data; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D018759:Adrenergic Uptake Inhibitors; D000069445:Atomoxetine Hydrochloride
keywords: Adult; Atomoxetine; Attention-deficit/hyperactivity disorder; Dosing; Length of therapy