How Frequent Is Switching from an Initial Stimulant Family to the Alternative One in the Clinical Setting? A Pilot Study of 49 Consecutively Referred Medication-Naive Adults with Attention-Deficit/Hyperactivity Disorder

Purpose/Background This study aimed to evaluate the frequency of needing to switch the initial treatment of a stimulant to the alternative family in newly referred, medication-naive adults with attention-deficit/hyperactivity disorder (ADHD) initiating treatment with stimulants. Methods/Procedures Subjects were 49 unmedicated adults (18-45 years old) with Diagnostic and Statistical Manual of Disorders (Fifth Edition) ADHD who initiated treatment with a stimulant. Before the clinical assessment with an expert clinician, participants completed the Adult Self-Report, Behavior Rating Inventory of Executive Function-Adult Version, Emotional Dysregulation Subscale of the Barkley Current Behavior Scale-Self-report, and Mind Wandering Questionnaire. The rate of switching was examined using information from the electronic medical record for up to three clinical follow-up visits. Comparisons were made between those who did and did not need to switch on baseline demographic and clinical characteristics. Findings/Results Sixty-seven percent of ADHD patients were initially prescribed a methylphenidate product, and 33%, an amphetamine product. Forty-one percent of ADHD patients needed to switch from their initially prescribed stimulant family within 90 days of initiating treatment because of poor tolerability. Whereas the rate of switching was significantly higher in those initially prescribed methylphenidate, the rate of patients who required changes in formulation (long-to short-acting and vice versa) or additional antianxiety or antidepressant treatment ("strugglers") was higher in those taking amphetamine. Switchers were more impaired on the Adult Self-Report Intrusive scale, whereas nonswitchers were more impaired on the Behavior Rating Inventory of Executive Function Inhibit and Task Monitor scales. However, these findings were small and of unclear clinical significance. Implications/Conclusions Forty-one percent of medication-naive adults with ADHD initiating stimulant treatment required a switch from the initially prescribed stimulant family to the alternative one because of poor tolerability. Switching could not be adequately predicted by baseline demographic or clinical characteristics. These findings call for improved efforts to help identify predictors of response to stimulant treatment in adults with ADHD to avoid unnecessary delays in identifying a safe and effective treatment for these patients.