Management of benign prostatic hyperplasia: role of phosphodiesterase-5 inhibitors

Effect of dose reduction of dutasteride in combination with alpha-blockers in patients with lower urinary tract symptoms/benign prostatic enlargement

Context

Dutasteride is used in the treatment of benign prostate enlargement with reported many side effects.

Aims

The purpose of this study is to examine how different doses of dutasteride (0.5 mg) in combination with tamsulosin affect the outcome of treatment of benign prostatic enlargement (BPE).

Settings and Design

Prospective study (phase III trial).

Subjects and Methods

Between April 2017 and March 2020, this randomized study was conducted on 300 patients with moderate-to-severe lower urinary tract symptoms attributable to BPE and a prostate volume of more than 40 cc. The patients were divided into three therapy groups at random (one-to-one randomization), each with 100 patients: (Group I) daily tamsulosin 0.4 mg plus dutasteride (0.5 mg). (Group II) every other day tamsulosin 0.4 mg plus dutasteride 0.5 mg. (Group III) once a week tamsulosin 0.4 mg plus dutasteride 0.5 mg.

Statistical Analysis

Statistical analysis was carried out with the help of the SPSS program 22. (IBM, Armonk, NY, USA). The mean and standard deviation (SD) are used to express quantitative data (SD). When comparing two means, an independent-samples t-test of significance was used. To compare more than two means, a one-way analysis of variance was utilized. For multiple comparisons between distinct variables, a post hoc test was performed.

Results

Patients were followed up every 3 months, with a 1-year follow-up to examine the medications' efficacy, prostate size reduction, and erectile function. After 1 year of treatment, all groups showed significant improvement in their symptom scores. However, Groups I and II experienced a considerable reduction in prostate size after therapy, but Group III experienced no meaningful reduction. In terms of sexual dysfunction, there was a considerable shift in Group I after 12 months.

Conclusions

Dutasteride treatment on the other day schedule has the same efficacy as the daily dose on prostate size at the same time; the other day scheduled dose has better preservation of sexual function.

The impact of adding solifenacin to tamsulosin therapy for treatment of storage lower urinary tract symptoms owing to benign prostatic hyperplasia

Background

Benign prostatic hyperplasia (BPH) is a common problem in aging males which has a potential impact on patients’ health-related quality of life. In the present prospective study, we evaluated the effect of adding solifenacin to tamsulosin, compared to tamsulosin alone on overactive bladder symptoms scores (OABSS) and patients’ quality of life (QoL) in patients with filling lower urinary tract symptoms due to BPH.

Methods

Patients included in our study were randomly assigned into 2 groups: group 1 included patients with BPH who received tamsulosin alone and group 2 included patients with BPH who received a combination of tamsulosin and sofinacin. Treatment period was 12 weeks in both groups. Quality of life and overactive bladder symptoms score questionnaires were obtained and compared in both groups before and after treatment.

Results

No significant differences were found between both groups before treatment. At the end of treatment period, The QoL score for Group 1 patients was significantly greater than the other group (mean rank was 138.98 in tamsulosin group versus 62.02 in the combination group, P-value < 0.01). Similarly, OABSS for tamsulosin only group was significantly higher than combined treatment patients (mean rank was 145.03 in tamsulin group versus 55.98 in the combination group, P-value < 0.01).

Conclusion

Adding solifenacin to tamsulosin was associated with an improvement of QoL and OABSS in patients with irritative urinary symptoms due to BPH when compared with tamsulosin monotherapy.

Two Birds with One Stone: Regular Use of PDE5 Inhibitors for Treating Male Patients with Erectile Dysfunction and Cardiovascular Diseases

Patients with cardiovascular disease (CVD) frequently have erectile dysfunction (ED) because the two conditions have similar risk factors and potential mechanisms. The therapeutic effect of CVD is strongly dependent upon long-term management of the condition. Patients with CVD tend to have poor medication compliance, and the coexistence of ED often discourages patients with CVD from continuing their long-term CVD management, thus worsening CVD treatment compliance. The two major reasons for poor compliance are that (i) the adverse effects of cardiovascular medications on erectile function drive people to reduce the prescribed dosage or even stop taking the medications to obtain satisfactory sexual arousal and (ii) a worsening mental state due to ED reduces medication compliance. The regular administration of phosphodiesterase-5 inhibitors (PDE5is) guarantees that the prescribed medication dosages are easy to comply with and that they improve the mental status of patients by enhancing their erectile function, resulting in improved long-term management of CVD through medication compliance. PDE5is themselves also play a role in reducing cardiovascular events and improving the prognosis. We recommend prescribing PDE5is for ED and suggest that PDE5i administration is a promising strategy to improve the long-term management of patients with both ED and CVD.

The link between vascular dysfunction, bladder ischemia, and aging bladder dysfunction

The vascular supply to the human bladder is derived mainly from the superior and inferior vesical arteries, the latter being directly connected to the internal iliac artery. Aging is associated with an impairment of blood vessel function and changes may occur in the vasculature at the molecular, cellular and functional level. Pelvic arterial insufficiency may play an important role in the development of bladder dysfunctions such as detrusor overactivity (DO) and the overactive bladder syndrome. Chronic ischemia-related bladder dysfunction may progress to bladder underactivity and it would be desirable to treat not only lower urinary tract symptoms (LUTS) induced by chronic ischemia, but also the progression of the morphological bladder changes. Studies in experimental models in rabbits and rats have shown that pelvic arterial insufficiency may result in significant bladder ischemia with reduced bladder wall oxygen tension. In turn, this will lead to oxidative stress associated with upregulation of oxidative stress-sensitive genes, increased muscarinic receptor activity, ultrastructural damage, and neurodegeneration. The phosphodiesterase type 5 (PDE5) inhibitor tadalafil, the α₁-adrenoceptor (AR) blocker silodosin, the β₃-AR agonist mirabegron, and the free radical scavenger melatonin, exerted a protecting effect on urodynamic parameters, and on functional and morphological changes of the bladder demonstrable in vitro. Since the agents tested are used clinically for relieving LUTS, the results from the animal models seem to have translational value, and may be of relevance for designing clinical studies to demonstrate if the drugs may prevent progression of ischemia-related functional and morphological bladder changes.

Drug interactions between antiretrovirals and drugs used to treat benign prostatic hyperplasia/lower urinary tract symptoms

INTRODUCTION

Significant advances in antiretroviral (ARV) therapy have transformed HIV into a chronic manageable disease. Co-morbidities associated with aging, such as benign prostatic hyperplasia (BPH), are becoming increasingly prevalent in the HIV-infected population. The pharmacological treatment of BPH involves medications mainly metabolized by CYP 450 enzymes, while many ARVs have inducing or inhibiting effects on the CYP 450 system. Consequently, there is potential for significant pharmacokinetic (PK) interactions between these two classes of medications.

AREAS COVERED

This article reviews the pharmacology and metabolism of selected BPH drug therapies and ARVs, in addition to highlighting potential interactions between these two drug categories. The authors also present PK evidence of interactions from available clinical trials, product monographs and international conference abstracts. Potentially significant drug interactions are summarized and strategies for management are discussed.

EXPERT OPINION

Drugs most likely to interact with BPH medications include protease inhibitors, the non-nucleoside reverse transcriptase inhibitors efavirenz, nevirapine, etravirine, and the cobicistat-boosted integrase inhibitor elvitegravir. Clinically significant PK interactions with BPH medications and dolutegravir, raltegravir, rilpivirine, or the investigational agent doravirine do not appear to exist. Clinicians working with HIV-infected individuals need to recognize the potential for interactions involving BPH and ARV treatments to ensure effective and safe drug therapy use.

Cyclic nucleotide phosphodiesterases: important signaling modulators and therapeutic targets

By catalyzing hydrolysis of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), cyclic nucleotide phosphodiesterases are critical regulators of their intracellular concentrations and their biological effects. As these intracellular second messengers control many cellular homeostatic processes, dysregulation of their signals and signaling pathways initiate or modulate pathophysiological pathways related to various disease states, including erectile dysfunction, pulmonary hypertension, acute refractory cardiac failure, intermittent claudication, chronic obstructive pulmonary disease, and psoriasis. Alterations in expression of PDEs and PDE-gene mutations (especially mutations in PDE6, PDE8B, PDE11A, and PDE4) have been implicated in various diseases and cancer pathologies. PDEs also play important role in formation and function of multimolecular signaling/regulatory complexes, called signalosomes. At specific intracellular locations, individual PDEs, together with pathway-specific signaling molecules, regulators, and effectors, are incorporated into specific signalosomes, where they facilitate and regulate compartmentalization of cyclic nucleotide signaling pathways and specific cellular functions. Currently, only a limited number of PDE inhibitors (PDE3, PDE4, PDE5 inhibitors) are used in clinical practice. Future paths to novel drug discovery include the crystal structure-based design approach, which has resulted in generation of more effective family-selective inhibitors, as well as burgeoning development of strategies to alter compartmentalized cyclic nucleotide signaling pathways by selectively targeting individual PDEs and their signalosome partners.