Introduction. The pathogenesis of lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH) is quite complex and may be associated with overactive bladder (OAB). Alpha-1-blockers are not effective enough to resolve irritative LUTS caused by OAB. According to recent studies, regulatory polypeptides of the bovine urinary bladder (Vesusten) have shown their efficiency in patients with OAB.
Aim. To evaluate the efficiency and safety of combination therapy of LUTS caused by BPH with alpha-1-blockers and Vesusten in comparison with standard monotherapy with alpha-1-blockers.
Materials and methods. An open, prospective, randomized, single-center study was carried out. In the main group, patients received Vesusten intramuscularly 3 times a week (a total of 10 doses) and an alpha-1-adrenoblocker daily, while in the control group patients received alpha-blockers as monotherapy. Uroflowmetry and ultrasound parameters, IPSS and OAB-q questionnaires, as well as adverse events (AE) were assessed.
Results. A total of 100 patients were included in the study, 93 of whom completed the protocol. The baseline characteristics of the groups were comparable, all patients received selective alpha-adrenoblockers (silodosin or tamsulosin) before inclusion in the study. The IPSS change in the main group was -2.43, compared to -0.38 in the control group (p<0.001). OAB-q parameters also significantly improved in the main group (-2.89 vs. -0.12; p<0.001). There was a significant decrease in the frequency of urinations per 72 hours in the group of combination therapy (-3 vs. -0.17 in the monotherapy group; p<0.001). Also, the voided volume significantly increased in the main group by an average of 27.4 ml (p<0.001), and the postvoid residual volume decreased by an average of 10.7 ml. Qmax and Qave significantly improved in the main group (+1.7 ml/s and +1.5 ml/s vs. +0.1 ml/s and +0.1 ml/s in the control group, respectively; p<0.001). A total of 17 mild AEs associated with intramuscular administration of Vesusten were recorded.
Conclusions. The addition of Vesusten to alpha-blockers in patients with LUTS and OAB caused by BPH significantly reduced irritative symptoms according to questionnaires, uroflowmetry and postvoid residual volume. Only mild local AEs were observed that did not require discontinuation of therapy.

Keywords: lower urinary tract syndromes (LUTS), overactive bladder (OAB), Vesusten, Benign Prostatic Hyperplasia (BPH), regulatory peptides