Tadalafil: a phosphodiesterase-5 inhibitor for benign prostatic hyperplasia

Comparison of Tamsulosin and Tadalafil effects in LUTS treatment considering patients' atherosclerosis risk level

Introduction

To date, no study evaluates the effect of atherosclerosis risk level on the efficacy of BPH drug therapies. Therefore, the present study aimed to assess the effect of atherosclerosis risk levels on the effectiveness of Tamsulosin and Tadalafil in LUTS treatment.

Methods

The present study was a randomized clinical trial that assessed men with LUTS symptoms (at least six months). The inclusion criteria were being older than 50 years, international prostate symptom score (IPSS) ≥ 13, and maximum urinary flow rate (Qmax) between 4 and 15 ml/s. Framingham Risk Score was used to measure atherosclerosis risk. The patients were classified into four groups, including group 1: Patients with low risk and treated with Tamsulosin (0.4 mg/day), group 2: Patients with low risk and treated with Tadalafil (5 mg/day), group 3: Patients with high risk and treated with Tamsulosin (0.4 mg/day), group 4: Patients with high risk and treated with Tadalafil (5 mg/day).

Results

The study included 44 and 38 patients receiving Tamsulosin and Tadalafil, respectively. The means (SD) of the baseline age for the Tamsulosin and Tadalafil groups were equal to 60.6 (6.8) and 58.8 (6.7), respectively (p-value = 0.213). The models revealed no impact of the atherosclerosis risk level on the drugs' effects (p-values = 0.378, 0.975, 0.743 for IPSS, QMAX, and VOID, respectively).

Conclusions

The present study's findings could not show the impact of atherosclerosis risk levels on the efficiency of Tamsolusin and Tadalafil in men with LUTS.

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Assessing the impact of atherosclerosis risk level on the effectiveness of Tamsulosin and Tadalafil in LUTS treatment.

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The present study's findings could not show the impact of atherosclerosis risk level on the efficiency of Tamsulosin and Tadalafil in men with LUTS.

The impact of preoperative lower urinary tract symptoms medication on the functional performance of holmium laser enucleation of the prostate

Introduction

Medical treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic obstruction (BPO) targets prostate size, to prevent disease progression, and prostate smooth muscle tone for rapid relieve of LUTS. Holmium laser enucleation of the prostate (HoLEP) is a size-independent method for surgical treatment of LUTS/BPO in medication-refractory patients and offers durable long-term results with reduced perioperative morbidity. As up to 50% of patients receive medical treatment for LUTS/BPO prior to surgery, we analyzed the impact of alpha-blockers and 5-alpha reductase inhibitors (5-ARI) on outcomes and perioperative morbidity in patients undergoing HoLEP for LUTS.

Material and methods

We retrospectively gathered data of 1,057 patients, who underwent HoLEP for LUTS/BPO from 2013–2018, and divided patients into group 1 (no medication), group 2 (α-blockers), and group 3 (5-ARI and α-blockers). Perioperative parameters, short-term functional outcomes and safety were assessed and statistical analysis was performed using SPSS V26.0 software.

Results

Even though preoperative LUTS profile was significantly different between groups, all patients improved significantly after HoLEP, irrespective of preoperative LUTS medication. Median improvement of IPSS was 9, 8 and 7 points, of Q_max was 10, 12 and 9.5 ml/s, with significant improvement of quality of life (QoL) and reduction of post-void residual volume (PVR) for groups 1–3, respectively, 30 days after surgery. With only 4.0% (42/1,057) of patients experiencing a Clavien-Dindo grade ≥II complication, there was no difference in prevalence of perioperative complications between groups (p = 0.943).

Conclusions

Although preoperative LUTS medication does not impair efficacy of HoLEP with acceptable perioperative morbidity, the time gap between medical therapy and surgical treatment may favor an earlier response.

Erectile dysfunction treatment with Phosphodiesterase-5 Inhibitors: Google trends analysis of last 10 years and COVID-19 pandemic

OBJECTIVES

We aimed to analyze the trend change of the most popular Phosphodiesterase-5 Inhibitors (PDE5i) over time and geography by using Google Trends (GT) data in 10 years period and COVID-19 pandemic.

MATERIALS AND METHODS

GT is able to generate a "line-graph", showing how interest has increased or decreased over a period within specific territories. The search values for specific terms are indexed as relative search volume (RSV), which is presented on a scale from 0-100. Avarage annual percentage change (AAPC) and RSV were analyzed to evaluate gain or loss of interest in trends. Search terms were generated for Food and Drug Administration (FDA)-approved PDE5i; tadalafil, sildenafil, vardenafil, avanafil, and their most-used brand names. The data was within "worldwide" from 1 January 2010, to 31 December 2020, using the ''global'' query category.

RESULTS

The overall interest in PDE5i has doubled. Sildenafil has become the most trend PDE5i of today with a regular increase (AAPC: 0.016, p < 0.01). Although the search trend of tadalafil remained almost constant until 2014, the rate of increase in the last 6 years raised and tadalafil has become the 2nd most popular PDE5i recently (AAPC: 0.007, p < 0.01). For vardenafil there has been a decreased interest (AAPC: -0.009, p < 0.01). There is no significant change in avanafil trend (AAPC: 0.000, p: 0.5). All PDE5i interest on GT decreased notably from February to June 2020. But after June, search trends reached the level before the COVID-19 period in a month.

CONCLUSIONS

These findings show us, with its increasing prevalence, erectile dysfunction (ED) has become a major public health problem. People from different geographies search the internet for ED treatment options. Patients should be informed that ED may be the first sign of many comorbid diseases, and patients with ED should be referred to a health institution for diagnosis and treatment.

Diketopiperazine-Based, Flexible Tadalafil Analogues: Synthesis, Crystal Structures and Biological Activity Profile

Phosphodiesterase 5 (PDE5) is one of the most extensively studied phosphodiesterases that is highly specific for cyclic-GMP hydrolysis. PDE5 became a target for drug development based on its efficacy for treatment of erectile dysfunction. In the present study, we synthesized four novel analogues of the phosphodiesterase type 5 (PDE5) inhibitor-tadalafil, which differs in (i) ligand flexibility (rigid structure of tadalafil vs. conformational flexibility of newly synthesized compounds), (ii) stereochemistry associated with applied amino acid building blocks, and (iii) substitution with bromine atom in the piperonyl moiety. For both the intermediate and final compounds as well as for the parent molecule, we have established the crystal structures and performed a detailed analysis of their structural features. The initial screening of the cytotoxic effect on 16 different human cancer and non-cancer derived cell lines revealed that in most cases, the parent compound exhibited a stronger cytotoxic effect than new derivatives, except for two cell lines: HEK 293T (derived from a normal embryonic kidney, that expresses a mutant version of SV40 large T antigen) and MCF7 (breast adenocarcinoma). Two independent studies on the inhibition of PDE5 activity, based on both pure enzyme assay and modulation of the release of nitric oxide from platelets under the influence of tadalafil and its analogues revealed that, unlike a reference compound that showed strong PDE5 inhibitory activity, the newly obtained compounds did not have a noticeable effect on PDE5 activity in the range of concentrations tested. Finally, we performed an investigation of the toxicological effect of synthesized compounds on Caenorhabditis elegans in the highest applied concentration of 6a,b and 7a,b (160 μM) and did not find any effect that would suggest disturbance to the life cycle of Caenorhabditis elegans. The lack of toxicity observed in Caenorhabditis elegans and enhanced, strengthened selectivity and activity toward the MCF7 cell line made 7a,b good leading structures for further structure activity optimization and makes 7a,b a reasonable starting point for the search of new, selective cytotoxic agents.

A phosphodiesterase 5 inhibitor, tadalafil, suppresses stromal predominance and inflammation in a rat model of nonbacterial prostatitis

BACKGROUND

Chronic inflammation is thought to be a major causative factor for the development of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Tadalafil, a phosphodiesterase type 5 inhibitor (PDE5-I), which has been used for the treatment of BPH-LUTS in daily practice, is known to act at several urinary organs. In this study, focused on the prostate, we examined the effect of tadalafil on the pathological changes and inflammatory factors in a rat nonbacterial prostatitis (NBP) model.

METHODS

Forty ten-month-old male Wistar rats were divided into nonbacterial prostatitis (NBP), NBP with tadalafil treatment (NBP-tadalafil), control, and control treated with tadalafil (control-tadalafil) groups (n = 10 per group). The NBP and NBP-tadalafil groups were castrated and then received daily subcutaneous 17β-estradiol for 30 days. The control-tadalafil and NBP-tadalafil groups were administered daily oral tadalafil for 30 days. All rats were then sacrificed and pathological changes and inflammatory factors were assessed in the prostatic tissues.

RESULTS

In the NBP group, the stroma-to-epithelium (S/E) ratio in the ventral prostate was significantly higher than in the control group (P < 0.001). In the NBP-tadalafil group, the S/E ratio was significantly lower than in the NBP group (P < 0.001). The macrophage levels and the extent of T-cell infiltration in the NBP-tadalafil group were significantly lower than in the NBP group (P < 0.005; P < 0.001, respectively). Compared with the NBP group, tissue concentrations of inflammatory cytokines, such as tumor necrosis factor-α, interleukin-8, and interleukin-1β, were significantly downregulated in the NBP-tadalafil group (P < 0.01; P < 0.05; P < 0.005, respectively).

CONCLUSIONS

Tadalafil suppressed stromal predominance and showed anti-inflammatory effects in a rat NBP model in association with downregulation of inflammatory cytokines.

Protective effect of tadalafil on the functional and structural changes of the rat ventral prostate caused by chronic pelvic ischemia

BACKGROUND

The etiology of Benign Prostatic Hyperplasia (BPH), a common among aged men, is not fully understood, however, in addition to androgens and aging, chronic ischemia has been proposed to contribute. Using an established rat model, we investigated whether chronic ischemia alters the structural and functional properties of the ventral rat prostate, and whether phosphodiesterase type 5 (PDE5) inhibitor (tadalafil) may have a protective action.

METHODS

Adult male Sprague-Dawley rats were divided into control, arterial endothelial injury (AI), and AI with tadalafil treatment (AI-tadalafil) groups. AI and AI-tadalafil groups underwent endothelial injury of the iliac arteries and received a 2% cholesterol diet following AI. AI-tadalafil rats were treated with tadalafil (2 mg/kg/day) orally for 8 weeks after AI. The control group received a regular diet. After 8 weeks, animals were sacrificed, and pharmacological and morphological studies on prostate tissues were performed.

RESULTS

Iliac arteries from AI rats displayed neo-intimal formation and luminal occlusion, an effect that was not prevented by tadalafil treatment. In the AI group, there was an obvious epithelial atrophy and a statistically significant increase in collagen fibers compared with the controls. Immunohistochemically, there was an up-regulation of smooth muscle α-actin (SMA). Contractile responses of prostate strips to KCl, electrical field stimulation (EFS), and phenylephrine (PE) were significantly higher after AI than in controls. Chronic treatment with tadalafil prevented the increase in contractile responses in ischemic tissue, and decreased the collagen deposition compared with the AI group.

CONCLUSIONS

In this rat model, chronic pelvic ischemia caused distinct functional and morphological changes in the prostate. Prostatic tissue from ischemic animals showed an increased contractile response to electrical and pharmacological stimulation, an increase in SMA, and an increased deposition of collagen. All these changes could be prevented by treatment with the PDE5 inhibitor, tadalafil, suggesting an involvement of cyclic guanosine monophosphate (cGMP).

Tissue injury and hypoxia promote malignant progression of prostate cancer by inducing CXCL13 expression in tumor myofibroblasts

Prostate cancer (PC) is a slowly progressing malignancy that often responds to androgen ablation or chemotherapy by becoming more aggressive, acquiring a neuroendocrine phenotype, and undergoing metastatic spread. We found that B lymphocytes recruited into regressing androgen-deprived tumors by C-X-C motif chemokine 13 (CXCL13), a chemokine whose expression correlates with clinical severity, play an important role in malignant progression and metastatic dissemination of PC. We now describe how androgen ablation induces CXCL13 expression. In both allografted and spontaneous mouse PC, CXCL13 is expressed by tumor-associated myofibroblasts that are activated on androgen ablation through a hypoxia-dependent mechanism. The same cells produce CXCL13 after chemotherapy. Myofibroblast activation and CXCL13 expression also occur in the normal prostate after androgen deprivation, and CXCL13 is expressed by myofibroblasts in human PC. Hypoxia activates hypoxia-inducible factor 1 (HIF-1) and induces autocrine TGF-β signaling that promotes myofibroblast activation and CXCL13 induction. In addition to TGF-β receptor kinase inhibitors, myofibroblast activation and CXCL13 induction are blocked by phosphodiesterase 5 (PDE5) inhibitors. Both inhibitor types and myofibroblast immunodepletion block the emergence of castration-resistant PC in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model of spontaneous metastatic PC with neuroendocrine differentiation.

Primary Care Evaluation and Treatment of Men With Lower Urinary Tract Symptoms

Lower urinary tract symptoms (LUTS) affect 50% to 90% of men aged 50 years or older. Primary care physicians should be knowledgeable about the diagnosis and management of this condition. The authors performed detailed PubMed searches using the terms lower urinary tract symptoms, benign prostatic hyperplasia, benign prostatic enlargement, and overactive bladder. The authors then reviewed the relevant literature on the evaluation and treatment of men with LUTS. According to the literature, accurate recognition of LUTS is predicated on a focused history and physical examination, as well as serum prostate-specific antigen measurement and urinalysis. For patients with mild symptoms, watchful waiting with ongoing monitoring and lifestyle modifications may be appropriate. For patients with moderate to severe symptoms, pharmacologic therapy is effective. When substantial LUTS persist despite appropriate pharmacologic therapy, specialty urologic evaluation and treatment is warranted.