Login to Access Video or Poster Abstract: MP69-01
Sources of Funding: none

Introduction

Overactive bladder (OAB) is characterized by urinary urgency, frequency, nocturia, and urinary incontinence (UI). The prevalence of OAB increases significantly with age. The first-line therapy for OAB is antimuscarinic medication, some of which have deleterious side-effects, including cognitive decline. We sought to examine the incidence and prevalence of antimuscarinic prescriptions among elderly persons ? age 65._x000D_

Methods

The 2006-12 National Ambulatory Medical Care Survey (NAMCS) were queried for patients with newly given or renewed prescriptions for any of 6 antimuscarinics: oxybutynin, tolterodine, fesoterodine, darifenacin, solifenacin, and trospium. Within these cohorts, frequencies of patient/physician attributes and annual trends in drug prescription were determined utilizing drug-mention weighting methodology.

Results

A weighted estimate of 47.68 million individuals (unweighted n=1,968) had their antimuscarinics renewed, and 12.77 million patients (unweighted n=641) received a new prescription (Table 1). The majority of new antimuscarinics were prescribed in elderly (? age 65) (55.2%), female (69.2%), white (61.7%), and Medicare insured (84.1%) individuals. Oxybutynin was a frequently prescribed (incidence 27.3%) and continued (prevalence 33.2 %) antimuscarinic among elderly patients. In 2010, there was a sharp decrease in the number of all continued antimuscarinic prescriptions, followed by annual increases in oxybutynin continuation versus continued decline in other antimuscarinic continuation (Figure 1).Figure 1: Continued Antimuscarinic Prescriptions in Patients > 65 Years of Age, NAMCS 2006-2012_x000D_

Conclusions

We found alarmingly high prescription rates of oxybutynin (27.3%), pharmacologically the least suitable antimuscarinic, for which studies have consistently demonstrated higher rates of cognitive impairment in the elderly. Frequent oxybutynin prescription is likely driven by tiered Medicare formularies which require patients to trial oxybutynin, a cheaper, generic antimuscarinic, before allowing access to newer, more costly yet safer, antimuscarinics. This work is the first population-based study demonstrating both the alarming rate of oxybutynin prescription and the lack of a proper safety net for a growing and vulnerable elderly population. Our work demands an increased consideration of the possible deleterious effects of unmonitored antimuscarinic use in elderly patients.

Funding

none