Efficacy and safety of tamsulosin versus its combination with mirabegron
in the management of benign prostatic Hyperplasia (BPH) with
predominantly coexisting overactive bladder symptoms (OABS) - An open
label randomised controlled clinical study.
Abstract
PURPOSE: We aim to do an efficacy-safety analysis of
Mirabegron-Tamsulosin combination therapy versus tamsulosin-placebo
monotherapy in a select subset of medication virgin BPH patients with
coexisting predominantly overactive bladder symptoms (OABS). METHODS:
After prior written informed consent and institutional ethics clearance,
80 patients of uncomplicated BPH with coexisting OABS and IPSS of
>7 were computer randomized and allocated to receive
therapy with either [50mg Mirabegronplus Tamsulosin 0.4 mg
(Intervention arm)]or [Tamsulosin 0.4 mg plus capsule lactobacillus
(Comparator arm)] once daily for a period of 8 weeks. Efficacy was
evaluated using the OABS Score (OABSS), mean change in the frequency of
nocturnal voiding, post void residue (PVR) and international prostate
symptom score (IPSS) while safety was assessed by recording treatment
emergent adverse events (TEAE). The protocol was registered
prospectively with the clinical trials registry of India
(CTRI/2018/12/016541). RESULTS: Significant improvements were visualised
in the primary endpoint total OABS subscore (OABSS-ss) at the end of 8
weeks in the combination group (mean difference -5.62 vs
-2.22p< 0.001).Similar significant improvements were seen with
most of the secondary parameters such as the mean change in voiding
episode/night, IPSS, IPSS-ss,OABS-ss, voided volume/micturition, Qmax,
and Quality of Life (QOL) indices (p<0.001). No significant
increase in PVR was observed in the Mirabegron arm and no patient
developed urinary retention. The TEAE were minor, self-limiting and were
managed symptomatically without any treatment discontinuity. CONCLUSION:
Mirabegron was significantly efficacious and safe in ameliorating OABS
induced by BPH versus placebo. This efficacy can be safely enhanced by
initiating Mirabegron-Tamsulosin combination therapy from the start in
medication virgin patients as opposed to the usual add on therapy
protocol. This combination appeared to be superior in terms of overall
safety, minimal side effects, better compliance and tolerability versus
Tamsulosin monotherapy particularly in the select subset of patients of
with BPH coexisting/predominant OABS.