We randomly divided 166 patients with BPH and concomitant OAB into a mild obstruction symptom group ( n = 88 ) and a moderate obstruction symptom group ( n = 78 ) , 48 of the former group treated with 0.2 mg tamsulosin + 5 mg solifenacin and the other 40 with 0.2 mg tamsulosin ; 36 of the latter group treated with 0.2 mg tamsulosin + 5 mg solifenacin and the other 42 with 0.2 mg tamsulosin , all administered once daily for 12 weeks .