Effect of Tamsulosin on Nocturnal Blood Pressure Load and Dipping Status: A Prospective Ambulatory Blood Pressure Monitoring Study

Background: Alpha-1 adrenergic receptor antagonists are widely used in the management of benign prostatic hyperplasia (BPH) . Their effects on blood pressure (BP) patterns remain incompletely characterized. This study aimed to prospectively evaluate the impact of tamsulosin on ambulatory blood pressure monitoring (ABPM) parameters, with particular focus on nocturnal BP load and dipping status. Methods: A total of 83 male patients aged 40–90 years who were initiated on tamsulosin for BPH-related lower urinary tract symptoms (LUTS) were prospectively enrolled; 58 patients with complete, technically adequate paired recordings were included in the final analysis. Participants underwent 24 h ABPM before treatment and at 1 month. Dipping status was defined as a nocturnal BP reduction ≥10%. Pre-post treatment ABPM parameters were compared using paired statistical analyses, and changes in dipping status were evaluated using McNemar’s test. Results: Mean 24 h, daytime, and nighttime systolic and diastolic blood pressure (DBP) values did not change significantly after treatment (p > 0.05). However, nocturnal systolic and DBP load decreased significantly following tamsulosin initiation (p = 0.035 and p = 0.005, respectively), along with a reduction in minimum DBP (p < 0.001). Changes in dipping status were heterogeneous: 25% of baseline non-dippers converted to a dipper pattern, whereas 36.4% of initial dippers became non-dippers, with no statistically significant overall shift (p = 0.81). Conclusions: At one month, tamsulosin was not associated with significant changes in mean ambulatory BP. Reductions in nocturnal BP load were observed, but the incremental clinical significance of BP load beyond mean ambulatory BP indices is uncertain. The marked decrease in minimum DBP warrants cautious interpretation as a potential safety signal. These findings should be considered exploratory and require confirmation in controlled studies incorporating earlier and longer follow-up.