The initial dose of tamsulosin for male LUTS differs between Western countries and Asian countries, including South Korea, Japan, Taiwan, and China. The initial dose of tamsulosin in Western countries is 0.4 mg, while an initial dose of 0.2 mg is frequently prescribed and recommended for Asian men with LUTS. Recent studies have reported that increasing the dose of tamsulosin to 0.4 mg is effective and safe in Asian men with LUTS who do not respond to an initial dose of 0.2 mg tamsulosin. However, it is still unclear whether tamsulosin 0.4 mg as the initial dose is effective and safe in Asian men with LUTS. To the best of our knowledge, only one randomized clinical, double-blind, phase 3 trial has been reported thus far. In that study, which was conducted in South Korea, tamsulosin 0.4 mg as an initial treatment showed favorable efficacy and tolerability and was more effective than tamsulosin 0.2 mg. However, the study was limited by the shortcomings inherent to many randomized controlled trials (RCTs): a small number of participants selected under strict inclusion and exclusion criteria. In turn, the results might not be generalizable to clinical practice.
 Therefore, we conducted this study to investigate the safety and efficacy of tamsulosin 0.4 mg as the initial dose in Korean men with moderate to severe LUTS using a large cohort of men seeking medical attention in everyday clinical practice.

A phase IV study was conducted in South Korea. Eligible patients were prescribed tamsulosin 0.4 mg for 6 months. We excluded patients with previous exposure to LUTS drugs and  patients with an international prostate symptom score (IPSS) <8.

The mean total IPSS, storage subscore, voiding symptoms subscore, and QoL significantly decreased from 18.0, 10.8, 7.2 and 3.8 to 12.8, 7.5, 5.3, and 2.6, respectively, after 6 months of treatment. The number of nocturia episodes significantly decreased from 3.0 to 2.2 in patients who reported at least 2 nocturia events at baseline. A mean reduction in the IPSS was quantitatively equivalent in all age groups. The mean reduction in the IPSS was greater in the IPSS≥20 group than in the IPSS<20 group (mean reduction in the total IPSS: -2.6 in the IPSS<20 group; -9.4 in the IPSS≥20 group). All Treatment-emergent adverse events (TEAEs) were mild. The most frequently recorded TEAE was dizziness, which was reported in 22 patients (1.8%).

Treatment of LUTS with tamsulosin 0.4 mg as the initial dose is safe and effective in Korean men.

Treatment of LUTS with tamsulosin 0.4 mg as the initial dose for 6 months in Korean men was effective in improving LUTS and showed a favorable safety profile in a real-life setting.