Abstract
Background: α1-Adrenoceptor blockers (α1Bs) are used for the treatment of benign prostatic hyperplasia and hypertension, but they are known to cause hypotension-related adverse events. The objective of the present study was to evaluate the onset time profiles for syncope associated with the use of α1Bs. Methods: We analyzed the data obtained from the Japanese Adverse Drug Event Report (JADER) database for a period from April 2004 until November 2016 and calculated reporting odds ratios (RORs) for eight α1Bs available on the Japanese market, using disproportionality analysis. Moreover, time information recorded in the JADER database was analyzed to evaluate the onset times of adverse events. Results: In total, 186,724 reports for males older than 20 years were analyzed. Significant RORs for syncope, with 95% confidence intervals, were obtained for naftopidil (2.53, 1.81 - 3.53), silodosin (4.24, 2.37 - 5.20), and tamsulosin (2.22, 1.75 - 2.81). The median onset times of syncope for naftopidil, silodosin, and tamsulosin were 37, 26, and 108 days, respectively. The shape parameters obtained by fitting the data for the three α1Bs to the Weibull distribution were all less than 1.0, indicating that all these drugs could be classified as the early failure type. The cumulative incidence rates showed that the onset times of syncope tended to be similar among the three α1Bs. Conclusions: Patients treated with selective α1Bs should be closely monitored for 100 days, especially in the first 20 to 40 days after initiation of silodosin or naftopidil. This information may be useful for patients and healthcare professionals in preventing syncope due to the use of selective α1Bs.
Highlights
Background: α1-Adrenoceptor blockers (α1Bs) are used for the treatment of benign prostatic hyperplasia and hypertension, but they are known to cause hypotension-related adverse events
Patients treated with selective α1Bs should be closely monitored for 100 days, especially in the first 20 to 40 days after initiation of silodosin or naftopidil
Selective α1Bs are used as first-line therapies for benign prostatic hyperplasia (BPH) [6]. α1-Adrenoceptors are classified into three subtypes
Summary
Background: α1-Adrenoceptor blockers (α1Bs) are used for the treatment of benign prostatic hyperplasia and hypertension, but they are known to cause hypotension-related adverse events. Conclusions: Patients treated with selective α1Bs should be closely monitored for 100 days, especially in the first 20 to 40 days after initiation of silodosin or naftopidil This information may be useful for patients and healthcare professionals in preventing syncope due to the use of selective α1Bs. α1-Adrenoceptor blockers (α1Bs) are most commonly indicated for the treatment of benign prostatic hyperplasia (BPH) but can be used for the treatment of hypertension because of their ability to decrease blood pressure. Α1-Adrenoceptor blockers (α1Bs) are most commonly indicated for the treatment of benign prostatic hyperplasia (BPH) but can be used for the treatment of hypertension because of their ability to decrease blood pressure These drugs are divided into two groups, depending on whether they display selectivity for α1-adrenoceptor subtypes (Table 1). As reported previously [15] [16] [17] [18], if an adverse event (e.g., syncope) is attributable to a drug, knowing in advance the approximate onset time and tendency α1 Subtype receptor selectivity
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