Association of silodosin, tamsulosin, and naftopidil with delirium: analysis of the pharmacovigilance database in Japan.

ABSTRACT

BACKGROUND: An association between adrenergic alpha-1 receptor antagonists and delirium has been suggested, but the details are unclear. AIM: This study investigated the association between adrenergic alpha-1 receptor antagonists and delirium in patients with benign prostatic hyperplasia using the Japanese Adverse Drug Event Report database. METHOD: First, disproportionality analysis compared the frequency of delirium in the adrenergic alpha-1 receptor antagonists silodosin, tamsulosin, and naftopidil. Next, multivariate logistic analysis was performed to examine the association between delirium and adrenergic alpha-1 receptor antagonists where disproportionality was detected. RESULTS: A disproportionality in delirium was observed in patients receiving tamsulosin (reporting odds ratio [ROR] 1.85, 95% confidence interval [CI] 1.38-2.44, P < 0.01) compared with those who did not, and also in patients receiving naftopidil (ROR 2.23, 95% CI 1.45-3.28, P < 0.01) compared with those who did not. Multivariate logistic analysis revealed that in addition to previously reported risk factors for delirium, delirium in patients receiving tamsulosin was significantly increased with concomitant use of anticholinergics (odds ratio 2.73, 95% CI 1.41-5.29, P < 0.01) and delirium in patients receiving naftopidil was significantly increased with concomitant use of beta3-adrenergic receptor agonists (odds ratio 4.19, 95% CI 1.66-10.6, P < 0.01). CONCLUSION: Anticholinergics or beta3-adrenergic receptor agonists to treat overactive bladder in patients receiving tamsulosin and naftopidil was strongly associated with delirium. Confirming the medical history and concomitant medications of patients receiving tamsulosin or naftopidil may contribute to preventing delirium in patients with benign prostatic hyperplasia and to improving their outcomes.