Predictive value of the immediate effect of first dose of tamsulosin on lower urinary tract symptoms improvement in benign prostatic hyperplasia patients

Objectives: The objective is to study the effect of tamsulosin within hours after the first dose and its prediction of the future improvement of LUTS. Materials and Methods: From May 2016 until August 2017, 340 patients aged over 40 years with benign prostatic hyperplasia (BPH)-related symptoms were prospectively enrolled; 0.4 mg tamsulosin for 3 months was given. The first visit was before beginning of tamsulosin; uroflowmetry (UFM), postvoid residual urine volume (PVR), international prostate symptom score (IPSS), and quality of life (QoL) were measured. The second visit was after 6 h from the administration of tamsulosin. UFM and PVR were measured. The third visit was after 1 month and the fourth visit was after 3 months, on which UFM, PVR, IPSS, and QoL were also measured. Results: The mean patients' age was 63 ± 6.18 and the mean prostate volume was 52.23 ± 24.59 cc. The mean Qmax at 1st, 2nd, 3rd, and 4th visits was 10.28 ± 3.06 s, 14.58 ± 4.84 s, 14.46 ± 4.94 s, and 14.28 ± 5.07 s, respectively, P = 0.04. The mean voiding time at 1st, 2nd, 3rd, and 4th visits was 41.24 ± 27.18 s, 33.84 ± 18.14 s, 31.96 ± 22.02 s, and 30.14 ± 17.52 s, respectively, P = 0.03. The mean PVR at 1st, 2nd, 3rd, and 4th visits was 46.40 ± 22.14 ml, 27.76 ± 26.10 ml, 25.16 ± 28.36 ml, and 25.58 ± 28.10 ml, respectively, P = 0.001. The first dose of tamsulosin significantly increases Qmax and decreases voiding time and residual urine (RU); there was no statistical significant difference between 1st dose, 1 and 3 months in Qmax, voiding time, and RU. QOL and IPSS were significantly improved after 1 and 3 months, P < 0.001. Conclusion: The first dose of tamsulosin improves UFM and predicts the mid-term change in UFM as well as IPSS and QoL indices in the treatment of BPH-related LUTS.