P203: Mixed Amphetamine Salts (MAS) Generic Drug Switching Trends: An Analysis of 2020 to 2023 U.S. Prescription Volume
Poster Presenter
Edward Kim
Analyst
FDA United States
Objectives
This retrospective observational study was conducted to assess switching patterns of amphetamine/dextroamphetamine-containing, or Mixed Amphetamine Salt (MAS), drug products using time-series national drug code (NDC) switching activity data among the U.S. patient population over 3-years.
Method
This study utilized IQVIA Longitudinal Prescription data to examine cross-sectional switch activity among the U.S. patient population treated with MAS over 3-years. Large sample sizes of non-inpatient retail prescription data were analyzed for switching patterns.
Results
There were 121.8 million (M) total prescriptions dispensed for MAS products from 2020 through 2022. Among all dispensed prescriptions, 18.5M were associated with a switch from a previous MAS product with a different NDC. There was an overall increase of patient MAS drug product switching (within 30 days), including restarting to different (switching after 30 days) MAS products. Switching remained relatively stable between 2020 to 2022 and increased from 2022 to 2023. Data suggest five NDCs accounted for over 20% of the switching and 10 NDCs with relatively small prescription dispensing (i.e., less than 2 million prescriptions dispensed) are above the average switch loss-to-total-prescription ratio among the top 30 NDCs.
Conclusion
Prescription stimulants to treat Attention Deficit Hyperactivity Disorder (ADHD) have been increasingly prescribed with expanded access across many demographics, including adolescents, adult females and adult males. Changes in prescribing may impact the prevalence of drug switching, which is widely known to occur for many drug products and can introduce outcomes such as changes in dosing schedules, reduced patient compliance, and increases in adverse events reporting. Evidence suggested higher rates of switching for five ER/IR MAS product NDCs compared to others; however, there is a need for additional research to differentiate MAS drug utilization patterns. As such, studies observing switching patterns have recommended continued postmarket surveillance of MAS and other stimulant products.
