Grant: Travel Awards - Institute Community Support

Therapeutic options and best practice treatment guidelines for Parkinson disease (PD) have changed significantly in the past 15 years, yet prescribing practices in the U.S. are unknown. The objective of our study was to describe patterns of antiparkinson drug utilization between January 2001 and December 2012 in a national cohort of individuals with PD. We also examined the impact of treatment guideline publication, drug introduction/withdrawal, and 'unofficial' prescribing forces on prescribing patterns. We retrospectively studied antiparkinson drug use among 16,785 individuals who were identified in a large US electronic medical record database. Our primary outcome was standardized annual prevalence of antiparkinson drug use by drug class from 2001 to 2012. We also compared antiparkinson medication trends and polypharmacy by age and sex. The most frequently prescribed PD drugs between 2001 and 2012 were levodopa (83%) and dopamine agonists (29%). Dopamine agonist use began to fall in 2007, from 37% to 25% in 2012, but the timing of the decline was more closely associated with adverse event reporting rather than publication of the American Academy of Neurology's (AAN) practice guideline refuting levodopa toxicity. Despite safety concerns for cognitive impairment and falls, individuals age 80 or more had stable rates (20%) of dopamine agonist use. Polypharmacy was most common in younger individuals. Dopamine agonist use declined from 2007 to 2012, suggesting that increased awareness of safety issues and the AAN practice guideline influenced prescribing. However, these events seemed to have little effect on the treatment provided to older adults with PD. Additionally, use of dopamine agonists did not begin to decline until two years after publication of the AAN's practice guideline, showing that the decline in dopamine agonist use was not immediate and may have been impacted by increasing safety concerns.