MATERIALS AND METHODS
A prospective randomised control study was performed on 80 eligible and consenting patients of BPH with predominantly OABS with the primary intent to treat, as per protocol inclusion criteria (newly diagnosed uncomplicated BPH of any size with predominant OABS and an IPSS >7 without any medical contraindications to the planned drug therapy or any absolute indication for surgery). Patients with prior history of anaphylaxis/hypersensitivity, drug therapy with metabolic interference to administered medication, prostatic/urethral surgery andother concomitant prostate diseases or neurogenic bladder were excluded from this study. Patients were computer randomised and allocated to either the intervention group (I) (Tamsulosin 0.4 mg plus 50mg Mirabegron tablet) or the comparator group (II) (Tamsulosin 0.4 mg plus capsule lactobacillus 1 capsules) with the medications administered at bedtime after meals for study period of two months (considering rapid onset of action of drugs in both the arms and their major side effects if any would be exhibited within this study time frame). Patients were evaluated as per protocol with (hemogram, LFT, KFT and urine routine, culture, ECG, ultrasound KUB+PVR and uroflow) during the initial visit (D0) prior to initiation of therapy. The efficacy outcome measure was evaluated by estimating the OABSS(primary outcome parameter)followed by the mean change nocturnal voiding frequency, PVR and IPSS (secondary efficacy parameters).Safety was assessed by monitoring for post therapy TEAE with follow up visits at the 2nd, 4th and 8th week post initiation of therapy. Fig-1 depicts flow of the current study protocol.
Statistical Analysis: Statistical analysis was performed using Statistical Package for the Social Sciences version 23.0 IBM™, New York, USA. The data was recorded in the MS Excel worksheet. Continuous data was analysed by unpaired Student’s t test while the Chi-square test and Repeated measure ANOVA was used to analyse the categorical data. P < .05 was considered statistically significant.
Power factor &sample size calculation: Based on a similar published comparative study by Ichihara et al7 in which 94 patients were randomised (76 completed the study) considering a standard deviation (SD) in the peak flow rate of 12.33 ± 1.22 in tamsulosin group and 10.5 ± 1.79 in the Mirabegron group with Power = 90% and α = 5% hence, to estimate this difference in mean value, the requisite sample size for significance was about 20 per group. We incorporated a study sample size of 80 (40 subjects in each group).