Tadalafil in the management of lower urinary tract symptoms: a review of the literature and current practices in Russia

Pharmacology of the lower urinary tract: update on LUTS treatment

The number of compounds used in the pharmacological treatment of lower urinary tract symptoms (LUTS) of patients who do not respond to conservative measures has been relatively stable during the last decade, with the exception of the introduction of the new class of β3 adrenoceptor agonists. However, different combinations have been investigated, and the long-term use of these compounds has raised new concerns about adherence and safety. This review summarizes the current state of pharmacology for LUTS, and presents a thorough discussion of the possible challenges concerning their future use. In this narrative review, we analyze the most recent articles related to LUTS pharmacotherapy, after an initial review of mechanisms of bladder function relevant in present clinical practice. The main problems with pharmacotherapy in LUTS are associated with its moderate efficacy, low persistence on treatment, and the incidence of short- and long-term adverse events (AE) associated with some compounds. The long-term AE, such as cognitive impairment in the elderly vulnerable patients associated with antimuscarinic drugs or persistent erectile dysfunction in sexually active men after treatment with 5-α-reductase inhibitors (5-ARI), are some of the problems addressed in this review. Combination therapy taking advantage of the synergistic mechanisms of action between some classes of compounds may overcome AE associated with dose escalation. LUTS pharmacotherapy offers moderate results to most patients but not a full cure. The use of combination drugs to achieve better clinical results, reduce AE and improve both efficacy and adherence, will be used more frequently in the future. The recently raised concern on potential long-term irreversible AE associated with some of these drugs, like antimuscarinics and 5-ARI, are critically important and require further investigation.

Tadalafil vs. tamsulosin in the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia: a prospective, randomized study

Introduction

To compare the efiicacy of tadalafil 5 mg with tamsulosin 0.4 mg in the treatment of Lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH).

Material and methods

A randomized prospective study on patients diagnosed with LUTS secondary to BPH with 50 patients in each group. Duration of the study is 12 weeks. Drug was given 30 min after dinner. Patients were assessed at baseline 1, 4 and 12 weeks with efficacy measures being Maximum flow rate (Qmax), Postvoid residual urine (PVR), International Prostate Symptom Score (IPSS), International Prostate Symptom Score Quality of life (IPSS QoL) and Sexual Health Inventory for Men (SHIM) scoring. Statistical analysis was done using paired sample t test and independent sample t test.

Results

In tadalafil group, 12 (24%) patients were having mild LUTS and 38 (76%) were having moderate LUTS. In tamsulosin group, 9 (18%) patients were having mild LUTS and 41 (82%) patients were having moderate LUTS. Seventeen patients in tadalafil group had associated ED (erectile dysfunction) and 13 patients had associated ED in tamsulosin group.

Conclusions

When both groups were compared, tamsulosin showed better efficacy than tadalafil in treating LUTS secondary to BPH.

Phosphodiesterase inhibitors for lower urinary tract symptoms consistent with benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) refers to non-malignant enlargement of the prostate gland that may cause bothersome lower urinary tract symptoms (LUTS). Alpha-blockers (ABs) and 5-alpha reductase inhibitors (5-ARIs) are the mainstay of medical treatment. Recently, phosphodiesterase inhibitors (PDEIs) that so far have been used mainly to treat erectile dysfunction were introduced to treat male LUTS.

OBJECTIVES

To assess the effects of PDEIs compared to placebo and other standard of care drugs (ABs and 5-ARIs) in men with LUTS consistent with BPH.

SEARCH METHODS

We conducted a systematic search of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Web of Science, and clinical trials registries of the World Health Organization (WHO) and the National Institutes of Health (NIH) (updated 2 August 2018). We performed citation tracking and handsearching of abstracts and conference proceedings. We also contacted study authors to ask for additional information.

SELECTION CRITERIA

We considered for inclusion in this systematic review randomised controlled trials (RCTs) comparing PDEIs versus placebo, ABs, or 5-ARIs for at least four weeks in men with BPH-LUTS.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened the literature and extracted data. Primary outcomes were effects on urinary symptoms as assessed by the International Prostate Symptom Score (IPSS-total; score ranging from 0 to 35, with higher values reflecting more symptoms), urinary bother as assessed by the Benign Prostatic Hyperplasia Impact Index (BPHII; score ranging from 0 to 13, with higher values reflecting more bother), and adverse events (AEs). We used GRADE to rate the quality of evidence. We considered short-term (up to 12 weeks) and long-term (12 weeks or longer) results separately.

MAIN RESULTS

We included a total of 16 randomised trials in this review. The results for primary outcomes are as follows.PDEI versus placebo: PDEIs may result in a small improvement in IPSS-total score (mean difference (MD) 1.89 lower, 95% confidence interval (CI) 2.27 lower to 1.50 lower; n = 4293; low-quality evidence) compared to placebo, and may reduce the BPHII score slightly (MD 0.52 lower, 95% CI 0.71 lower to 0.33 lower; n = 3646; low-quality evidence). Rates of AEs may be increased (risk ratio (RR) 1.42, 95% CI 1.21 to 1.67; n = 4386; low-quality evidence). This corresponds to 95 more AEs per 1000 participants (95% CI 47 more to 151 more per 1000). Study results were limited to a treatment duration of six to 12 weeks.PDEI versus AB: PDEIs and ABs probably provide similar improvement in IPSS-total score (MD 0.22 higher, 95% CI 0.49 lower to 0.93 higher; n = 933; moderate-quality evidence) and may have a similar effect on BPHII score (MD 0.03 higher, 95% CI 1.10 lower to 1.16 higher; n = 550; low-quality evidence) and AEs (RR 1.35, 95% CI 0.80 to 2.30; n = 936; low-quality evidence). This corresponds to 71 more AEs per 1000 participants (95% CI 41 fewer to 264 more per 1000). Study results were limited to a treatment duration of six to 12 weeks.PDEI and AB versus AB alone: the combination of PDEI and AB may provide a small improvement in IPSS-total score (MD 2.56 lower, 95% CI 3.92 lower to 1.19 lower; n = 193; low-quality evidence) compared to AB alone. We found no evidence for BPHII scores. AEs may be increased (RR 2.81, 95% CI 1.53 to 5.17; n = 194; moderate-quality evidence). This corresponds to 235 more AEs per 1000 participants (95% CI 69 more to 542 more per 1000). Study results were limited to treatment duration of four to 12 weeks.PDEI and AB versus PDEI alone: the combination of PDEI and AB may provide a small improvement in IPSS-total (MD 2.4 lower, 95% CI 6.47 lower to 1.67 higher; n = 40; low-quality evidence) compared to PDEI alone. We found no data on BPHII or AEs. Study results were limited to a treatment duration of four weeks.PDEI and 5-ARI versus 5-ARI alone: in the short term (up to 12 weeks), the combination of PDEI and 5-ARI probably results in a small improvement in IPSS-total score (MD 1.40 lower, 95% CI 2.24 lower to 0.56 lower; n = 695; moderate-quality evidence) compared to 5-ARI alone. We found no evidence on BPHII scores or AEs. In the long term (13 to 26 weeks), the combination of PDEI and 5-ARI likely results in a small reduction in IPSS-total score (MD 1.00 less, 95% CI 1.83 lower to 0.17 lower; n = 695; moderate-quality evidence). We found no evidence about effects on BPHII scores. There may be no difference in rates of AEs (RR 1.07, 95% CI 0.84 to 1.36; n = 695; low-quality evidence). This corresponds to 19 more AEs per 1000 participants (95% CI 43 fewer to 98 more per 1000).We found no trials comparing other combinations of treatments or comparing different PDEI agents.

AUTHORS' CONCLUSIONS

Compared to placebo, PDEI likely leads to a small reduction in IPSS-total and BPHII sores, with a possible increase in AEs. There may be no differences between PDEI and AB with regards to improvement in IPSS-total, BPHII, and incidence of AEs. There appears to be no added benefit of PDEI combined with AB compared to PDEI or AB alone or PDEI combined with 5-ARI compared to ARI alone with regards to urinary symptoms. Most evidence was limited to short-term treatment up to 12 weeks and of moderate or low certainty.

Drug-related problems in patients with erectile dysfunctions and multiple comorbidities

This study was conducted in a tertiary medical center in Kuala Lumpur, Malaysia. A total of 200 erectile dysfunction (ED) patients with 499 cases who had received pharmacological treatments for their ED participated in this study. Types, causes and factors associated with drug-related problems (DRPs) in ED patients with multiple comorbidities were assessed. A total of 244 DRPs with an average of 1.2±2.1 DRPs per patient were identified. Drug interaction contributed the most to DRPs occurrence. There was a significant higher risk of DRPs in patients with benign prostatic hyperplasia, lower urinary tract infection and elderly and end-stage renal disease. Early identification of types of DRPs and factors associated may enhance their prevention and management.

Predictors of Individual Response to Placebo or Tadalafil 5mg among Men with Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia: An Integrated Clinical Data Mining Analysis

BACKGROUND

A significant percentage of patients with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) achieve clinically meaningful improvement when receiving placebo or tadalafil 5mg once daily. However, individual patient characteristics associated with treatment response are unknown.

METHODS

This integrated clinical data mining analysis was designed to identify factors associated with a clinically meaningful response to placebo or tadalafil 5mg once daily in an individual patient with LUTS-BPH. Analyses were performed on pooled data from four randomized, placebo-controlled, double-blind, clinical studies, including about 1,500 patients, from which 107 baseline characteristics were selected and 8 response criteria. The split set evaluation method (1,000 repeats) was used to estimate prediction accuracy, with the database randomly split into training and test subsets. Logistic Regression (LR), Decision Tree (DT), Support Vector Machine (SVM) and Random Forest (RF) models were then generated on the training subset and used to predict response in the test subset. Prediction models were generated for placebo and tadalafil 5mg once daily Receiver Operating Curve (ROC) analysis was used to select optimal prediction models lying on the ROC surface.

FINDINGS

International Prostate Symptom Score (IPSS) baseline group (mild/moderate vs. severe) for active treatment and placebo achieved the highest combined sensitivity and specificity of 70% and ~50% for all analyses, respectively. This was below the sensitivity and specificity threshold of 80% that would enable reliable allocation of an individual patient to either the responder or non-responder group.

CONCLUSIONS

This extensive clinical data mining study in LUTS-BPH did not identify baseline clinical or demographic characteristics that were sufficiently predictive of an individual patient response to placebo or once daily tadalafil 5mg. However, the study reaffirms the efficacy of tadalalfil 5mg once daily in the treatment of LUTS-BPH in the majority of patients and the importance of evaluating individual patient need in selecting the most appropriate treatment.

The new horizons of pharmacotherapy. Unexpected pharmacological actions and a new therapeutic strategy of phosphodiesterase-5 inhibitors

INTRODUCTION

Benign prostate hyperplasia and erectile dysfunction affect a significant subset of men. BPH and ED may have the same promoting conditions and are the strong predicting risk factors to each other. A significant number of these patients are bothered by lower urinary tract symptoms (LUTS). Direct correlation of age, sexual dysfunction and LUTS severity has been well documented. Many sexually dysfunctional patients with concomitant BPH receive alpha-adrenergic antagonists and any Phosphodiesterase-5 (PDE5) inhibitor simultaneously. PDE5 inhibitors relieve LUTS symptoms in the course of BPH and reduce independent detrusor contractions. This paper presents the results of clinical trials on the efficacy of PDE5 inhibitors on LUTS, new perspectives on its use and newly-identified side effects.

MATERIAL AND METHODS

The review is based on an internet search of PubMed and Medscape databases. The search terms were as follows: LUTS and ED, BPH and phosphodiesterase-5 inhibitors, LUTS clinical trials, phosphodiesterase-5 inhibitors mechanisms.

RESULTS

Clinical trials show an epidemiological and pathophysiological relationship between BPH, LUTS and ED. Numerous studies reveal the alleviating effect of phosphodiesterase-5 inhibitors on LUTS, expressed as the reduction of IPSS score, but not followed by a change in Qmax. Opponents raise a link of PDE5 inhibitors with increased risk of melanoma. New studies reveal that phosphodiesterase-5 inhibitors are effective in the treatment of neurological disorders.

CONCLUSIONS

Researches reveal the efficacy of phosphodiesterase-5 inhibitors in LUTS along with an improvement of erectile function. The molecular mechanism of action of such drugs suggests imminent novel applications. Potential benefits will be multidimensional. Unfortunately, interfering with particular molecular mechanisms may alleviate some diseases, but may lay groundwork for others - new and even more devastating.