Intradetrusor OnabotulinumtoxinA Safety and Efficacy in Patients 80 Years and Older: A Retrospective Cohort Study

Overactive bladder (OAB) has higher prevalence and increased morbidity in older people. Owing to side effects and inefficacy of OAB medications, patients frequently choose onabotulinumtoxin A intradetrusor injections (BTX-A). There is limited research investigating efficacy and adverse event (AE) rates of BTX-A in older female populations. Our objective was to evaluate rates of BTX-A discontinuation, treatment failure, UTI, and retention in women ≥ 80 compared to younger cohorts.

This retrospective cohort study included a convenience sample of women who underwent in-office BTX-A for OAB between 1/2014 and 12/2020. Data was analyzed with Kruskal-Wallis, ANOVA, chi-square, and Fisher's exact tests.

Overall, 547 women were included with 215 (39%) < 65 years old, 249 (46%) 65-79, and 83 (15%) ≥ 80. When comparing age cohorts, rate of BTX-A discontinuation increased with age (54% at < 65, 58% 65-79, 72% ≥ 80, p = 0.01) with no significant difference in discontinuation due to ineffectiveness (19% < 65, 28% 65-79, 23% ≥ 80, p = 0.22). Those < 65 had the lowest rate of UTI (19%), but UTI rate was the same for women 65-79 (29%) and ≥ 80 (29%, p < 0.01). Rates of retention were highest in women 65-79 (8% < 65, 17% 65-79, 8% ≥ 80, p = 0.01).

Women ≥ 80 years old were most likely to discontinue BTX-A but discontinuing for ineffectiveness was the same regardless of age. Women > 65 are more likely to experience UTI after BTX-A; however, AEs do not significantly increase in women ≥ 80 years old, making BTX-A a good option in elderly patients.