Date of Award
1-1-2024
Document Type
Dissertation
Degree Name
Ph.D. in Pharmaceutical Sciences
First Advisor
John P. Bentley
Second Advisor
Sujith Ramachandran
Third Advisor
Kaustuv Bhattacharya
School
University of Mississippi
Relational Format
dissertation/thesis
Abstract
This dissertation examined prescription stimulant medication (PSM) use among older adults in the United States from 2012-2020 by (1) assessing annual prevalence and describing clinical characteristics and treatment patterns among new PSM users, (2) evaluating the association between PSM initiation and risk of adverse events such as stroke, myocardial infarction, and all-cause mortality, and (3) analyzing trends in the concomitant use of PSMs and antidepressants. The study utilized 5% national sample of Medicare administrative claims from 2012-2020.
First, the study identified an increase in the annual prevalence of PSM use from 0.44% in 2012 to 0.63% in 2020 among older adults. While PSM use remained relatively low, more than half of the new PSM users lacked an FDA-approved or recognized off-label indication, with ADHD and narcolepsy diagnoses present in only a small proportion of cases. Methylphenidate was the most prescribed PSM, followed by amphetamine-dextroamphetamine, with the mean treatment duration being approximately 11 months.
Second, the study evaluated the association between PSM initiation and adverse cardiovascular outcomes through a propensity score-matched cohort. Results demonstrated a higher risk of stroke and composite cardiovascular outcomes within the first 30 days of PSM use, with the elevated risk persisting up to 365 days in an intention-to-treat analysis. No significant association was observed between PSM exposure and myocardial infarction, and preexisting hypertension did not moderate outcome risk in any model.
Lastly, the study assessed trends in concomitant PSM and antidepressant use, often employed as adjunctive therapy for geriatric depression. The findings indicated stable concomitant use over time, with the highest overlap occurring with selective serotonin reuptake inhibitors (SSRIs). Predictors of concomitant use included gender, race, geographic region, and history of cardiovascular and mental health conditions. Additionally, 66.5% of individuals with overlapping prescriptions received both medications from the same prescriber.
Study findings provide important insights into PSM use patterns, clinical risks implications for older adults, emphasizing the need for careful monitoring and tailored treatment approaches to optimize the safety of PSM therapy in this population.
Recommended Citation
Jadhav, Saumil, "Breaking Old: Trends and Adverse Events of Prescription Stimulant Use in Older Adults" (2024). Electronic Theses and Dissertations. 3017.
https://egrove.olemiss.edu/etd/3017
