Medication use in adults with attention deficit/hyperactivity disorder in a commercially-insured population in the United States

Objective: To examine real-world prescription medication usage among commercially-insured adults with attention deficit/hyperactivity disorder (ADHD) in the US. Methods: Adults with ADHD who received >1 ADHD medication during 2013 were identified from a large US claims database. Combination therapy was defined as an overlap of >= 30 days between the index (first treatment >= 30 days in 2013) and another medication(s). Patients were classified into six groups: long-acting (LA) monotherapy, short-acting (SA) monotherapy, LA+LA, SA+SA, LA+SA, and >2 therapies. Analyses compared baseline characteristics by regimen, ranked combination regimens, and estimated daily average consumption (DACON) for monotherapy users. Results: Of 206,443 adults with ADHD (mean age = 32.9 years; 51.6% female), 56.9% used LA monotherapy, 30.7% SA monotherapy, and 12.5% used combination therapies (LA+SA: 10.3%; LA+LA: 1.3%; SA+SA: 0.4%; >2 therapies: 0.5%). Extended-release mixed amphetamine salts (MAS-XR, 39.2%) and lisdexamfetamine (LDX, 31.5%) were the most common LA monotherapies. Nearly all SA monotherapy patients received immediate-release mixed amphetamine salts (MAS-IR; 81.7%). The top three therapies among combination categories were: (a) LA+LA: branded MAS-XR+generic MAS-XR (13.7%), LDX+eneric MAS-XR (10.8%), LDX+guanfacine ER (10.7%); (b) SA+SA: generic MAS-IR+clonidine IR (33.5%), generic MAS-IR+generic MPH SA (17.9%), branded MAS-IR+generic MAS-IR (11.1%); (c) LA+SA: generic MAS-XR+/-IR (39.2%), LDX+generic MAS-IR (16.7%), LA+SA generic MPH (12.6%). Among monotherapy users, DACON was 1.2 +/- 0.6 (LA) and 2.1 +/- 0.9 (SA) tablets. Conclusions: There is significant treatment heterogeneity among US adults with ADHD. A sizable proportion of patients received monotherapies at above the recommended dosages or combination therapies, suggesting existing single-tablet regimens may not meet patients' needs.