Treatment with rivastigmine or galantamine and risk of urinary incontinence: results from a Dutch database study

Treatment of Alzheimer disease (AD) with cholinesterase inhibitors (ChEIs) may increase the risk of urinary incontinence (UI). Objective: To assess whether ChEI use was associated with the risk of UI among older patients with AD. Methods: A crossover cohort study using the PHARMO Record Linkage System included 10years of data on drug dispensing histories for over two million Dutch residents. Included patients were aged 50 +, free of UI for the last 6months, received a first ChEI prescription during the study period, had at least 12months prior drug exposure history and one subsequent prescription of any drug. UI was defined as a first dispensing of a urinary spasmolytic or of incontinence products for at least 30days. Cox regression with time-varying covariates and multivariate adjustment allowed assessing whether UI incidence was associated with ChEI exposure. Results: Among 3154 patients there were 657 UI cases during a mean follow-up of 5.1years before a first ChEI dispensing, and 499 cases after ChEI initiation, during a mean follow-up of 2.0years. Among the 2700 participants free of UI one year before ChEI initiation, the adjusted hazard ratio (HR) for UI was 1.13 (95% CI: 0.97-1.32) when periods with ChEI use were compared to periods without ChEI use. Sensitivity analyses may suggest an increased risk in the 1^st month after ChEI initiation (HR: 1.72, p=0.09) Conclusion: Worsening AD may increase incidence of UI, but no firm association between ChEI treatment and risk of UI could be shown from these data.