Beta testing the potential link between the alpha antagonist tamsulosin and dementia

Cumulative use of therapeutic bladder anticholinergics and the risk of dementia in patients with lower urinary tract symptoms: a nationwide 12-year cohort study

Background

Studies have shown an association between lower urinary tract symptoms (LUTS) and an increased risk of dementia. Whether anticholinergic use contributes to the development of dementia in patients with LUTS remains unknown, especially in Asian populations. This study aims to investigate the association between anticholinergic use and dementia in patients with LUTS.

Methods

This study included patients aged 50 years and over with newly diagnosed LUTS (January 2001 to December 2005), divided into four groups according to their cumulative defined daily doses (cDDDs) of anticholinergics: < 28 cDDDs, 28–84 cDDDs, 85–336 cDDDs, ≥337 cDDDs. Patients were followed up until dementia developed or until the end of 2012.

Results

We recruited a total of 16,412 patients. The incidence of dementia was 10% in the < 28 cDDD group, 8.9% in the 28–84 cDDD group, 11.5% in the 85–336 cDDD group, and 14.4% in the ≥337 cDDD group (p = .005). In a Cox proportional hazards analysis, the adjusted hazard ratio of dementia was 1.15 (95% CI = 0.97–1.37) in the 85–336 cDDD group, and 1.40 (95% CI = 1.12–1.75) in the ≥337 cDDD group after adjusting for covariates.

Conclusions

Our study indicates that higher cumulative anticholinergic exposure is associated with an increase in the risk of incident dementia in patients with LUTS aged 50 years of age and over. Either using one anticholinergic agent or switching anticholinergic agents cumulatively increases this risk. Therapeutic risks and benefits of using anticholinergics in LUTS treatment should be clinically reviewed and weighed.

Is Tamsulosin Linked to Dementia in the Elderly?

PURPOSE OF REVIEW

Lower urinary tract symptoms (LUTS) result from age-related changes in detrusor function and prostatic growth that are driven by alterations in the ratio of circulating androgens and estrogens. Alpha-adrenergic receptor blockers are commonly used to treat LUTS because they influence urethral tone and intra-urethral pressure. Molecular cloning studies have identified three α₁-adrenergic receptor subtypes (α_1A, α_1B, and α_1D). The α_1A subtype is predominant in the human prostate but is also present in many parts of the brain that direct cognitive function. Tamsulosin is the most widely used α₁-adrenergic receptor antagonist with 12.6 million prescriptions filled in 2010 alone. When compared to the other common types of α₁-adrenergic receptor antagonists (i.e., terazosin, doxazosin, and alfuzosin), tamsulosin is 10- to 38-fold more selective for the α_1A versus the α_1B subtype.

RECENT FINDINGS

Duan et al. have recently shown that men taking tamsulosin have a higher risk of developing dementia when compared to men taking other α-adrenergic antagonists or no α-adrenergic antagonists at all (HR 1.17; 95% CI 1.14-1.21). Based upon this retrospective analysis, we believe that tamsulosin, because of its unique affinity for α_1A-adrenergic receptors, may increase the risk of developing dementia when used for an extended period of time. If these findings are confirmed, they carry significant public health implications for an aging society.