Characteristic Group 1 (n=41) Group 2 (n=30) Group 3 (n=36) Group 4 (n=34) 45.50±11.09 20:10 24.34±1.00 5.73±1.57 12/18 3.07±1.55 42.33±12.58 25:11 24.10±0.97 5.81±1.26 19/17 2.53±1.18 43.65±10.87 18:16 24.42±0.93 5.59±1.44 14/20 2.82±1.14 Values are presented as mean±SD. Group 1, tamsulosin 0.2 mg once; Group 2, tamsulosin 0.2 mg twice; Group 3, alfuzosin 10 mg; Group 4, control group. a: Statistical significance was analyzed by one-way analysis of variance, b: Statistical significance was analyzed by chi-square test. Group 1 (n=41) Group 2 (n=30) Group 3 (n=36) Group 4 (n=34) Stone expulsion rate at 28 days Mean days to stone expulsion 32 (78.0) 8.47±5.51 23 (76.7) 7.83±5.08 27 (75.0) 8.22±5.96 16 (47.1) 13.56±6.49 Values are presented as number (%) or mean±SD. Group 1, tamsulosin 0.2 mg once; Group 2, tamsulosin 0.2 mg twice; Group 3, alfuzosin 10 mg; Group 4, control group. p-value 0.696a 0.287b 0.476a 0.757a 0.588b 0.217a 351 2 (6.7) 1 (3.3) 2 (6.7) 3 (10.0) 2 (6.7) 2 (6.7) 3 (10.0) 0 (0) 2 (5.6) 2 (5.6) 3 (8.3) 2 (5.6) 4 (11.1) 3 (8.3) 0 (0) 0 (0) 2 (5.9) 2 (5.9) 4 (11.8) 2 (5.9) 4 (11.8) Comparison and Efficacy of Alpha Blockers in MET TABLE 1. Baseline patient characteristics Mean age (yr) Sex (male:female) Body mass index (kg/m2) Stone size (mm) Stone side (right/left) Symptom duration (day) 45.07±13.77 31:10 24.18±0.88 5.49±1.31 18/23 3.15±1.56 TABLE 2. Results according to treatment TABLE 3. Adverse effects observed in patients Retrograde ejaculation Orthostatic hypotension Headache Dizziness Diarrhea Fatigue Nausea/vomiting 2 (4.9) 1 (2.4) 2 (4.9) 2 (4.9) 2 (4.9) 2 (4.9) 4 (9.8) Symptom/sign Group 1 (n=41) Group 2 (n=30) Group 3 (n=36) Group 4 (n=34) Values are presented as number (%). Group 1, tamsulosin 0.2 mg once; Group 2, tamsulosin 0.2 mg twice; Group 3, alfuzosin 10 mg; Group 4, control group. Statistical significance was analyzed by the Pearson's chi-square and Fischer's exact test. There were no statistically significant differ- ences in any groups. (47.1%). A statistically significant difference was noted be- tween groups 1 and 4 (p=0.008), groups 2 and 4 (p=0.021), and groups 3 and 4 (p=0.026), whereas no significant differ- ence was recorded between groups 1 and 2 (p=1.000), groups 1 and 3 (p=0.793), and groups 2 and 3 (p=1.000). The demographic data are summarized in Table 2. 3. Stone expulsion time The mean time to stone expulsion was 8.47±5.51 days in group 1, 7.82±5.08 days in group 2, 8.22±5.96 days in group 3, and 13.56±6.49 days in group 4. A statistically sig- nificant difference was noted between groups 1 and 4 (p=0.007), groups 2 and 4 (p=0.004), and groups 3 and 4 (p=0.009), whereas no significant difference was recorded between groups 1 and 2 (p=0.661), groups 1 and 3 (p=0.870), and groups 2 and 3 (p=0.803). The demographic data are summarized in Table 2. 4. Side effects observed in the study and control groups No severe complications were recorded in the four groups. Two patients (4.9%) in group 1 and two patients (6.7%) in group 2 recorded retrograde ejaculation. One patient (2.4 %) in group 1, one patient (3.3 %) in group 2, and two pa- tients (5.6 %) in group 3 recorded one episode of orthostatic hypotension that did not require suspension of the therapy. There were no statistically significant differences between the groups in terms of retrograde ejaculation, orthostatic hypotension, headache, dizziness, diarrhea, fatigue, nau- sea, or vomiting (p＞0.05). The demographic data are sum- marized in Table 3. During the course of the study, none of the patients experienced intractable pain, fever, or se- vere hydronephrosis that required urgent intervention. A total of 43 patients who did not pass the stone within 4 weeks were treated by using SWL or ureteroscopy. Korean J Urol 2012;53:349-354