Effectiveness and safety of silodosin in the treatment of lower urinary tract symptoms in patients with benign prostatic hyperplasia: A European phase IV clinical study (SiRE study)

Safety and efficacy of tamsulosin 0.4 mg as an initial dose in 1,219 Korean patients with moderate to severe lower urinary tract symptoms: data from a phase IV study

Background

An initial dose of tamsulosin 0.2 mg is frequently prescribed for Asian men. We investigated the safety and efficacy of tamsulosin 0.4 mg as the initial dose in Korean men with moderate to severe lower urinary tract symptoms (LUTSs) in everyday clinical practice.

Materials and methods

A phase IV study was conducted in South Korea. Eligible patients were prescribed tamsulosin 0.4 mg for 6 months. We excluded patients with previous exposure to LUTS drugs and patients with an international prostate symptom score (IPSS) < 8.

Results

The mean total IPSS, storage subscore, voiding symptoms subscore, and quality of life significantly decreased from 18.0, 10.8, 7.2, and 3.8 to 12.8, 7.5, 5.3, and 2.6, respectively, after 6 months of treatment. The number of nocturia episodes significantly decreased from 3.0 to 2.2 in patients who reported at least 2 nocturia events at baseline. A mean reduction in the IPSS was quantitatively equivalent in all age groups. The mean reduction in the IPSS was greater in the IPSS ≥ 20 group than in the IPSS < 20 group (mean reduction in the total IPSS: -2.6 in the IPSS < 20 group; -9.4 in the IPSS ≥ 20 group). All treatment-emergent adverse events were mild. The most frequently recorded treatment-emergent adverse event was dizziness, which was reported in 22 patients (1.8%).

Conclusion

Treatment of LUTS with tamsulosin 0.4 mg as the initial dose for 6 months in Korean men was effective in improving LUTS and showed a favorable safety profile in a real-life setting.

Evolving Role of Silodosin for the Treatment of Urological Disorders – A Narrative Review

Use of α-androgenic receptor blockers remains a mainstay therapeutic approach for the treatment of urological diseases. Silodosin is recommended over other α-blockers for the treatment of lower urinary tract symptoms (LUTS) and benign prostate hyperplasia (BPH), due to its high α_1A uroselectivity. Current research data suggest that silodosin is efficacious in the management of various urological diseases. Thus, we herein review the current evidence of silodosin related to its efficacy and tolerability and appraise the available literature that might ultimately aid in management of various urological conditions at routine clinical practice. Literature reveals that silodosin is beneficial in improving nocturia events related to LUTS/BPH. Silodosin exerts effect on relaxing muscles involved in detrusor obstruction, therefore prolonging the need for patients undergoing invasive surgery. Silodosin treatment, either as a monotherapy or combination, significantly improves International Prostate Symptom Score (IPSS) including both storage and voiding symptoms in patients with BPH/LUTS. Patients on other treatment therapies such as phosphodiesterase 5 inhibitors or other α-blockers are well managed with this drug. Steadily, silodosin has proved beneficial in the treatment of other urological disorders such as chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), overactive bladder/acute urinary retention (AUR), premature ejaculation (PE), and prostate cancer post brachytherapy-induced progression. In patients with distal ureteral stones, silodosin treatment is beneficial in decreasing stone expulsion time without affecting stone expulsion rate or analgesic need. Moreover, there were significant improvements in intravaginal ejaculation latency time, quality of life scores, and decrease in PE profile among patients with PE. Silodosin has also demonstrated promising results in increasing the likelihood of successful trial without catheter in patients with AUR and those taking antihypertensive drugs. Reports from Phase II studies have shown promising role of silodosin in the treatment of CP/CPPS as well as facilitating ureteral stone passage. From the robust data in this review, further silodosin treatment strategies in the management of different urological conditions need to be focused on.

Evaluation of Alpha 1 Adrenoceptor Antagonist Dose Increase Therapy: An Essential Strategy for Patients with Lower Urinary Tract Symptoms Associated with Benign Prostatic Hyperplasia

Introduction

There have been a number of reports on dose increase therapy (DI-T) with the alpha 1 adrenoceptor antagonists (α1-blockers) naftopidil and tamsulosin for lower urinary tract symptoms associated with benign prostatic hyperplasia.

Methods and Results

The reports on DI-T (naftopidil 75 mg/d, tamsulosin 0.4 mg/d) in non-responders to low-dose initial therapy (LI-T, naftopidil 50 mg/d, tamsulosin 0.2 mg/d) were summarized. In each study, a non-responder was defined as a patient without sufficient improvements on the International Prostate Symptom Score (IPSS), IPSS Quality of Life, maximum flow rate of urine, or treatment satisfaction. These reports showed that 22.4-76.1% of patients were non-responders to LI-T, indicating that a novel treatment strategy for such patients is important. Moreover, 22.5-90.0% of non-responders to LI-T showed a response to DI-T, which achieved the same level of efficacy as low-dose maintenance therapy. Specifically, the improvements of the IPSS voiding symptom sub-score and maximum flow rate of urine were superior. The predictive factors for non-response to α1-blockers LI-T were insufficient improvement of subjective symptoms and objective findings during LI-T. These patients require high-dose initial therapy or DI-T at an early stage, since adverse events associated with naftopidil and tamsulosin do not show a dose-response relationship.

Conclusions

DI-T with α1-blockers has high potential as an essential treatment strategy for lower urinary tract symptoms associated with benign prostatic hyperplasia.

Changing Aspects of Male Sexual Functions Accompanying Treatment of Benign Prostatic Hyperplasia With Silodosin 8 mg Per Day

BACKGROUND

Alpha-adrenergic antagonist treatment for benign prostatic hyperplasia (BPH) and drug-related sexual side effects are frequent in aging men.

AIM

To investigate functional changes in erectile and ejaculatory aspects of male sexuality under Silodosin 8 mg per day treatment for BPH.

METHODS

Sexually active patients diagnosed with BPH and who initiated Silodosin treatment were the subjects of the study. The International Prostate Symptom Score, premature ejaculation patient profile (PEP-male) questionnaire, Sexual Health Inventory for Men (SHIM) questionnaire, and estimated intravaginal ejaculation latency time (IELT) values of the participants were used to evaluate sexual functions. Data evaluation was performed in 8 urology clinics retrospectively.

OUTCOMES

Participant ratings for SHIM, PEP, and estimated IELT were the primary outcome measures in the study.

RESULTS

Among 187 recruited patients, data of 98 patients, who completed the trial period in the study, were eligible. The median age of the eligible participants who completed the trial period for 3 months was 59.5 years (range 45-82). 16 patients of 187 (8%) reported a desire for drug withdrawal for anejaculation during the recruitment period. 46 (46.9%) and 49 (50%) patients reported anejaculation in the first and third month of the treatment, respectively. De novo erectile dysfunction was noticed in 15 patients (15.3%). There was a significant increase in the estimated IELT of subjects in both the first (P = .01) and third (P = .002) month. SHIM-1 (P = .008), SHIM-total (P = .009), and PEP scores (P = .008) were also improved in the third month of the treatment. Neither baseline patient characteristics nor changes in the International Prostate Symptom Score after treatment predicted final outcomes with multivariable analysis. The subgroup analysis of participants who reported "anejaculation" also revealed better outcomes compared with participants ejaculating naturally in the third month as per SHIM ratings.

CLINICAL IMPLICATIONS

Despite several male patients having dry orgasms due to Silodosin-induced anejaculation, the majority experienced improved erectile function.

STRENGTHS & LIMITATIONS

The present study demonstrated pioneering results while investigating both erectile and ejaculatory dimensions of the male sexual function during Silodosin treatment for BPH. However, lack of partner evaluation, low follow-up rates, and lack of knowledge about reasons why subjects are lost to follow-up after drug initiation have limited our interpretation.

CONCLUSION

Most patients using Silodosin 8 mg per day for BPH treatment experienced improvement in their erectile function, estimated IELT, and premature ejaculation profile in the third month of the treatment. Underlying mechanisms and reasons for individual differences necessitate further investigation. Cihan A, Kazaz İO, Yıldırım Ö, et al. Changing Aspects of Male Sexual Functions Accompanying Treatment of Benign Prostatic Hyperplasia With Silodosin 8 mg Per Day. J Sex Med 2020;17:1094-1100.

Clinical Efficacy of Silodosin in Patients with Severe Lower Urinary Tract Symptoms Related to Benign Prostatic Obstruction: A Pooled Analysis of Phase 3 and 4 Trials

We performed a post hoc analysis of data from phase 3 and 4 studies to evaluate the efficacy of silodosin 8mg in patients with severe lower urinary tract symptoms (LUTS) related to benign prostatic obstruction (BPO). The presence of two or more of the following criteria was adopted to define severity: total International Prostate Symptom Score (IPSS) 20-35, quality of life (QoL) score 5-6, maximum urinary flow <5ml/s or postvoid residual volume ≥100ml, and prostate volume ≥50ml. Mean improvements in total (8.1 vs 4.7), storage (3.1 vs 2.0), voiding (5.0 vs 2.7), and QoL (1.3 vs 0.7) IPSS scores were significantly greater for patients receiving silodosin compared to placebo (all p< 0.0001). Mean improvements in total, storage, voiding, and QoL IPSS scores were similar for the severe and not severe LUTS cohorts. In conclusion, silodosin significantly improves symptoms and QoL in all LUTS/BPO patients, including those with severe symptoms. PATIENT SUMMARY: Silodosin improves symptoms and quality of life for patients with severe lower urinary tract symptoms related to benign prostatic obstruction.

Silodosin: An Update on Efficacy, Safety and Clinical Indications in Urology

INTRODUCTION

Silodosin determines smooth muscle relaxation in bladder and prostate tissues, increases bladder blood flow in conditions of chronic bladder ischemia and regulates the activity of transcriptional factors responsible for stromal growth and prostate hyperplasia. Phase III trials have already demonstrated the efficacy and safety of silodosin in the treatment of patients bothered by lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH).

OBJECTIVE

We aimed to describe the rationality for the use of silodosin and to summarize the current literature on the use of Silodosin for the treatment of LUTS.

METHODS

PubMed and Web of Science were queried with the terms: 'silodosin' in combination (AND) with the terms 'lower urinary tract symptoms', 'LUTS', 'pathophysiology', 'symptoms' OR 'therapy'. Studies published in the last 10 years (2007-2017) in adults and core clinical journals in English were included.

RESULTS

Silodosin 8 mg once-daily was superior to placebo in improving IPSS total score, voiding subscore, storage subscore and QoL score, and at least as effective as tamsulosin 0.4 mg once-daily in all the efficacy analyses. In addition, studies assessing the effect on urodynamic parameters showed that silodosin determined a higher improvement in the bladder outlet obstruction index compared to other alpha1 adrenergic receptor antagonists. Concerning the safety profile, long-term data (after 9 months of treatment) confirmed the limited effect of silodosin on the cardiovascular and gastrointestinal systems. Although ejaculatory disorders represented the main complaint of patients taking silodosin, the discontinuation rate due to this condition remained low even in a long-term follow-up study (7.5%). Encouraging findings showed that silodosin may be administered as a medical expulsive therapy for promoting spontaneous stone passage of distal ureteral stones < 10 mm, to relieve LUTS in patients who underwent prostate cancer brachytherapy and to increase the likelihood of successful trials without a catheter in patients experiencing acute urinary retention.

CONCLUSION

Silodosin is one of the drugs approved for the treatment of BPH, being highly effective in improving not only LUTS but also urodynamic parameter impairments secondary to BPH. Moreover, it has shown efficacy as medical expulsive therapy for distal ureteral stones in previous prospective randomized trials.

FUNDING

Sponsorship for this study and article processing charges were funded by Recordati.

Efficacy and safety of silodosin in the treatment of lower urinary tract symptoms in elderly men taking antihypertensive medications

Background

Both hypertension and lower urinary tract symptoms (LUTS) are common conditions in the elderly population. This study investigated the efficacy and safety of silodosin in the treatment of LUTS in elderly men who were taking antihypertensive medications.

Methods

This is an observational study which collected the medical records of patients who started silodosin medication for their LUTS between April 2015 and December 2015. Inclusion criteria were age ≥ 65 years, currently taking antihypertensive medication, and International Prostate Symptom Score (IPSS) ≥ 8. Pretreatment evaluation included IPSS, Male Sexual Health Questionnaire, systemic symptoms, blood pressure, and uroflowmetry. Post-treatment evaluation was performed 3 months after the initial administration of silodosin medication.

Results

Mean age of the total 48 patients was 70.7 ± 5.2 years. Thirty-two (66.7%) patients who continued silodosin single treatment showed a significant decrease in IPSS Quality of life scores (4.2 ± 1.1 vs. 3.0 ± 1.6, P = 0.001) and an increase in the maximum flow rate (10.7 ± 6.0 mL/s vs. 14.0 ± 4.5 mL/s, P = 0.001). Blood pressures did not change, and none of the patients needed to adjust their antihypertensive medication. New development of orthostatic hypotension was observed in one (2.5%) patient. Among the six patients who had orthostatic hypotension before silodosin treatment, none of the patients showed symptom aggravation. Ejaculatory dysfunction that required discontinuation of silodosin medication developed in only one (2.5%) patient.

Conclusion

Silodosin is an effective and safe agent in elderly men who are taking antihypertensive medications. Silodosin has an advantage in the treatment of LUTS in this population, even if the patients have orthostatic hypotension before treatment.

α1-Blockers in Men with Lower Urinary Tract Symptoms Suggestive of Benign Prostatic Obstruction: Is Silodosin Different?

Available α1-blockers (ABs) have different profiles of receptor selectivity. Silodosin exhibits the highest selectivity for the α_1A adrenergic receptor. This pharmacological feature couples with a singular urodynamic and clinical profile. The magnitude of bladder outlet obstruction improvement in patients receiving silodosin is higher if compared to other ABs. From a clinical point of view, current evidence suggests an advantage in favor of silodosin in terms of nocturia improvement and cardiovascular safety. The incidence of ejaculatory dysfunction with silodosin is higher compared to other Abs.