Potential side effects of currently available pharmacotherapies in male lower urinary tract symptoms suggestive of benign prostatic hyperplasia

INTRODUCTION

The drug classes of α1-adrenoceptor antagonists, 5α-reductase inhibitors, and phosphodiesterase type 5 inhibitors are guideline-recommended treatments of lower urinary tract symptoms suggestive of benign prostatic hyperplasia; muscarinic receptor antagonists and β3-adrenoceptor agonists are also recommended if storage symptoms are insufficiently addressed with one of the other three drug classes.

AREAS COVERED

We provide a narrative review (no formalized literature searches performed) of the tolerability of these drug classes with emphasis on the more recently introduced medications, on combination treatment, and on more lately emerging risks.

EXPERT OPINION/COMMENTARY

The tolerability profiles are distinct between drug classes but, with few exceptions, similar within a drug class. Within a drug, formulations with longer duration of action tend to have better tolerability. Efficacy gains using combination treatment at least partly come at a cost of lesser tolerability. Greater susceptibility to experience adverse events based on age, comorbidities, and comedications appears conceptually important but remains under-investigated in this therapeutic area.

Comparative Efficacy of Different Drugs for Lower Urinary Tract Symptoms due to Benign Prostatic Hyperplasia: A Bayesian Network Meta-Analysis

Background: Lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH) are common in middle-aged and elderly men. The current drugs for treating this disease include α1-adrenoceptor antagonists (ABs), muscarinic receptor antagonists (MRAs), phosphodiesterase five inhibitors (PDE5-Is), and β3-adrenoceptor agonists (B3As). However, direct comparative studies analyzing different therapies are limited; therefore, we conducted a network meta-analysis (NMA) to evaluate the efficacy of different drug regimens for treating BPH/LUTS. Methods: The PubMed, EMbase, Web of Science, and Cochrane Library databases were searched to collect randomized controlled trials (RCTs) of different drug treatments for BPH/LUTS from January 2000 to April 2021. The NMA was performed using R 4.1 software. Results: Fifty-five RCTs were included among a total of 1639 trials. ① ABs + PDE5-Is, ABs + B3As, ABs + MRAs, ABs, and PDE5-IS were superior to the placebo in improving the total International Prostate Symptom Score (IPSS), IPSS-Voiding, and IPSS-storage. ② For increasing the maximum flow rate (Qmax), ABs + PDE5-Is, ABs + MRAs, and ABs were more effective than the placebo. ③ Regarding reducing post-void residual urine (PVR), none of the six treatment plans had significant effects. Conclusion: Combination therapy showed greater efficacy than monotherapy, and ABs + PDE5-Is was the most successful treatment for improving the overall IPSS score. ABs are a primary therapeutic measure to increase Qmax, and ABs + PDE5-I may be a more suitable choice for enhancing Qmax. The combination of MRA and AB+ MRA may lead to an increase in PVR. Systematic Review Registration: [website], identifier [registration number].

Discontinuation Rates of Tadalafil Alone and in Combination with a-Blockers in the Treatment of Male Lower Urinary Tract Symptoms with or without Coexisting Erectile Dysfunction: A Systematic Review and Meta-Analysis

PURPOSE

We examined the discontinuation rates of tadalafil alone and in combination with a-blockers (ABs) for the treatment of male lower urinary tract symptoms (LUTS), with or without erectile dysfunction (ED).

MATERIALS AND METHODS

We searched the EMBASE, PubMed, Web of Science, Scopus, Cochrane Library, and ClinicalTrials.gov databases for studies published until May 15, 2022. The discontinuation rates associated with LUTS medications were subsequently analyzed by meta-analysis.

RESULTS

Forty-four studies, including 1724 discontinued patients, were included. The combined discontinuation rate was 12.78% (95% confidence interval (CI) 9.89-15.98%), and the discontinuation rates because of adverse events and lack of efficacy were 4.56% (95% CI 3.39-5.90%) and 3.30% (95% CI 1.53-5.72%), respectively.

CONCLUSIONS

The discontinuation rate of tadalafil alone or in combination with ABs for LUTS with or without ED was relatively low and varied according to the study type. Patients receiving monotherapy or combination therapy were similarly likely to abandon treatment. Treatment with a fixed-dose combination was associated with better persistence than with a free-dose combination. These data may help guide clinicians in selecting drug regimens when making decisions. Factors associated with treatment withdrawal need to be determined through high-quality clinical studies to reduce the drug discontinuation rate, which will ultimately reduce healthcare costs and improve patient outcomes.

Which Drug to Discontinue 3 Months After Combination Therapy of Tadalafil plus Tamsulosin for Men with Lower Urinary Tract Symptom and Erectile Dysfunction? Results of a Prospective Observational Trial

BACKGROUND

Safety and efficacy of tamsulosin and tadalafil for men with benign prostatic enlargement (BPE) and/or erectile dysfunction (ED) are defined. However, there are only a few pilot studies on combination therapy with these drugs for men with lower urinary tract symptom (LUTS)/BPE and ED. Moreover, preliminary reports are limited to 12 wk, without any information about subsequent therapies.

OBJECTIVE

To evaluate the impact of discontinuation of tamsulosin versus tadalafil 12 wk after combination therapy.

DESIGN, SETTING, AND PARTICIPANTS

Fifty consecutive patients with moderate-to-severe LUTS (International Prostate Symptom Score [IPSS] > 7) and mild-to-severe ED (International Index of Erectile Function-5 [IIEF-5] < 22) were treated with combination therapy (tamsulosin 0.4mg/d plus tadalafil 5mg/d) for 12 wk. After 12 wk, 25 patients discontinued tamsulosin (Group TAD), while 25 patients discontinued tadalafil (Group TAM).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Efficacy variables were IPSS (total, voiding, storage) and IIEF-5. Paired samples t test and analysis of variance were used.

RESULTS AND LIMITATIONS

Groups TAD and TAM presented similar features (age, BMI, metabolic profile) including symptoms scores at baseline. Similar and significant improvements in IPSS (total, voiding, and storage) and IIEF-5 were recorded in both groups after 12 wk of combination therapy (all p< 0.001). Total IPSS was similar between the two groups at the end of the trial. However, we found between-group significant differences from baseline to 24 wk and from 12 to 24 wk in storage-IPSS (Group TAD: -3.32 vs Group TAM: -1.24, p= 0.002; Group TAD: +0.24 vs Group TAM: +1.20, p= 0.040, respectively) and in IIEF-5 (Group TAD: +4.64 vs Group TAM: +0.16, p< 0.001; Group TAD: -1.64 vs Group TAM: -4.40, p= 0.003). No significant treatment-related adverse event was recorded in both groups.

CONCLUSIONS

After 12 wk of combination therapy, monotherapy with tadalafil for further 12 wk allows to preserve the improvement of storage IPSS and IIEF-5, in addition to total IPSS.

PATIENT SUMMARY

In this report we evaluated the discontinuation of tamsulosin or tadalafil after 12 wk of combination therapy. We found that tadalafil monotherapy, for a further 12 wk, aids in retaining the improvement of storage symptoms and erectile function.