Tadalafil - a therapeutic option in the management of BPH-LUTS

Tadalafil versus pentoxifylline in the management of diabetic kidney disease: a randomized clinical trial

AIMS

To investigate the efficacy and safety of tadalafil (TAD) versus pentoxifylline (PTX) in the management of diabetic kidney disease (DKD). Some animal studies and clinical trials reported that tadalafil and pentoxifylline have a reducing effect on different blood glucose parameters and lipid profiles which contribute to progress the patients with diabetes mellitus (DM) to DKD.

METHODS

From February 2022 to March 2023, 90 patients with type 2 DM and DKD (micro-albuminuria) were enrolled in this randomized-controlled study. The patients were randomized into three equal groups: control group, TAD group, and PTX group. The three groups received traditional blood glucose lowering therapy + ramipril 10 mg PO. The TAD group also received tadalafil 20 mg PO every other day. The PTX group also received pentoxifylline 400 mg PO twice daily.

RESULTS

Both TAD and PTX groups produced statistically significant improvement in the primary outcomes by a significant reduction in Urinary albumin/creatinine ratio (UACR) which was pronounced by a reduction percentage of-47.47%, -53.73% respectively. In addition to a significant decrease in Hemoglobin A1C (HbA1c) (mmol/mol), Fasting blood glucose (FBG), 2-h postprandial blood glucose (2-h PPG) (p < 0.001). Only the PTX group showed a significant increase in Cr Cl and a significant decrease in S. Cr (p < 0.001). Only the TAD group showed a significant increase in high-density lipoprotein-cholesterol (HDL-C) (p < 0.001), while the PTX group showed a significant decrease in low-density lipoprotein-cholesterol (LDL-C) (p-value 0.011), and triglyceride (p-value 0.002). Both TAD and PTX groups showed a decrease in tumor necrosis factor-α (TNF-α) which was significant only in the PTX group (p < 0.001). There was a significant increase in malondialdehyde (MDA) (p < 0.001), and an increase in urinary neutrophil gelatinase-associated Lipocalin (uNGAL) (p-value 0.850, 0.014 respectively) which was significant only in the PTX group.

CONCLUSIONS

The use of tadalafil or pentoxifylline may serve as an effective adjuvant therapy for patients with diabetic kidney disease.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT05487755, July 25, 2022.

Pharmacological Approaches in Managing Symptomatic Relief of Benign Prostatic Hyperplasia: A Comprehensive Review

Benign Prostatic Hyperplasia (BPH) is a prevalent condition that affects aging men, leading to the development of lower urinary tract symptoms (LUTS) and potentially severe complications such as complete obstruction. The management of BPH typically involves the use of medications from different classes, including alpha-1 antagonists, 5-alpha reductase inhibitors, and anticholinergics. Combination therapy utilizing drugs from different classes can also effectively manage the BPH-LUTS complex. Recent research has revealed that phosphodiesterase 5 (PDE5) inhibitors, including Tadalafil and Sildenafil, are highly effective in treating LUTS associated with BPH. Tadalafil as a monotherapy has recently been shown to significantly improve LUTS in BPH patients. Additionally, the use of herbal remedies as a treatment option for BPH has also been widely debated. Previous research suggests that saw palmetto can reduce BPH symptoms through several proposed mechanisms, but recent trials have found inconsistencies in its efficacy. In this literature review, we conducted an extensive PubMed database search to provide current and comprehensive insights into BPH treatment options. This review comprehensively evaluates available treatments for managing BPH, highlighting the effectiveness of different classes of medications and combination therapies in managing associated symptoms. The present investigation also discusses recent research on the efficacy of PDE5 inhibitors in treating LUTS associated with BPH and the uncertain efficacy of herbal remedies. The insights provided by this study can guide healthcare professionals in making informed decisions about managing BPH, ultimately improving patient outcomes.

Feasibility of high-dose tadalafil and effects on insulin resistance in well-controlled patients with type 2 diabetes (MAKROTAD): a single-centre, double-blind, randomised, placebo-controlled, cross-over phase 2 trial

Background

Phosphodiesterase-5 inhibitors exert positive vascular and metabolic effects in type 2 diabetes (T2D), but the effect on insulin resistance in T2D is unclear.

Methods

This randomised, double blind, placebo-controlled, two-period crossover trial was conducted at Sahlgrenska University Hospital (Gothenburg, Sweden). Men without apparent erectile dysfunction (age 40-70 years) and women (age 55-70 years, post-menopause) diagnosed with T2D between 3 months and 10 years, haemoglobin A1c (HbA1c) < 60 mmol/mol and a body mass index (BMI) 27-40 kg/m² were enrolled. Participants were randomly assigned to one period of oral tadalafil 20 mg once a day and one period of placebo for 6 weeks, separated by an 8-week wash-out period. Placebo and tadalafil tablets were made visually indistinguishable and delivered randomized in two separate boxes for each participant. Both treatment periods ended with a glucose clamp, and measurements of body composition and metabolic markers in blood, subcutaneous and muscular interstitial fluid. The primary aim was to assess difference in whole-body insulin resistance after 6-weeks of treatment, determined after completion of the two study arms, and secondary aims were to study effects of tadalafil on pathophysiology of T2D as well as tolerability of high-dose tadalafil in T2D. Primary analysis was performed in participants with full analysis set (FAS) and safety analysis in all participants who received at least one dose of study medication. This trial is registered with ClinicalTrials.gov (NCT02601989), and EudraCT (2015-000573).

Findings

Between January 22nd, 2016, and January 31st, 2019, 23 participants with T2D were enrolled, of whom 18 were included in the full analysis set. The effect of tadalafil on insulin resistance was neutral compared with placebo. However, tadalafil decreased glycaemia measured as HbA1c (mean difference -2.50 mmol/mol, 95% confidence interval (CI), -4.20; -0.78, p = 0.005), and, further, we observed amelioration of endothelial function and markers of liver steatosis and glycolysis, whereas no statistically significant differences of other clinical phenotyping were shown. Muscle pain, dyspepsia, and headache were more frequent in participants on high-dose tadalafil compared with placebo (p < 0.05) but no difference between treatments appeared for serious adverse events.

Interpretation

High-dose tadalafil does not decrease whole-body insulin resistance, but increases microcirculation, induces positive effects in the liver and in intermediate metabolites, in parallel with an improved metabolic control measured as HbA1c. High-dose tadalafil is moderately well tolerated, warranting larger trials to define the optimal treatment regimen in T2D.

Funding

The Swedish Research Council, Swedish Diabetes Foundation, Novo Nordisk Foundation, the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement, Sahlgrenska University Hospital funds, Gothenburg Society of Medicine, Eli Lilly & Company, USA, and Eli Lilly & Company, Sweden AB.

Tunable and Cooperative Catalysis for Enantioselective Pictet-Spengler Reaction with Varied Nitrogen-Containing Heterocyclic Carboxaldehydes

Herein we report an organocatalytic enantioselective functionalization of heterocyclic carboxaldehydes via the Pictet-Spengler reaction. Through careful pairing of novel squaramide and Brønsted acid catalysts, our method tolerates a breadth of heterocycles, enabling preparation of a series of heterocycle conjugated β-(tetrahydro)carbolines in good yield and enantioselectivity. Careful selection of carboxylic acid co-catalyst is essential for toleration of a variety of regioisomeric heterocycles. Utility is demonstrated via the three-step stereoselective preparation of pyridine-containing analogues of potent selective estrogen receptor downregulator and U.S. FDA approved drug Tadalafil.

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.

Effect of daily tadalafil on reported outcomes in patients with erectile dysfunction and depressive symptoms: STROBE, a case-control study

Erectile dysfunction (ED) and depression are closely related. We sought to determine ED and depression were improved by tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor, at 5 mg daily, in this case-control study.Participants were men aged 20 to 65 years with ED for >3 months, International Index of Erectile Function-5 (IIEF) score <21 points, and Zung Self-Rating Depression Scale (SDS) survey result >50 points who were willing to participate.On first visit (V1) and after 1 (V2) and 2 months (V3), clinical features were examined using IIEF-5 for diagnosing and evaluating ED, SDS for evaluating depression, and International Prostate Symptom Score and Quality of Life (IPSS/QoL) survey for examining lower urinary tract symptoms (LUTS). Tadalafil 5 mg was administered daily for 2 months.A total of 60 participants were an average age of 58.68 ± 6.71 years. Patient overall average IIEF was 8.76 ± 5.98, showing mild ED symptoms, and total average IPSS 13.74 ± 7.55 showed moderate LUTS. Average overall SDS index was 58.93 ± 9.21, indicating moderate-to-severe findings. Average change in IIEF among all patients revealed significant improvement from V1 to V2 (-2.69 ± 1.22, P = .03) and V1 to V3 (-4.38 ± 1.20, P < 0.01). IPSS also significantly improved from V1 to V3 (3.48 ± 1.37, P = .01), as did SDS index (V1, V2: 4.69 ± 1.89, P = 0.02), (V1, V3: 5.43 ± 1.89, P < .01). Patients with severe IIEF scores (group 1, n = 27) experienced significantly greater improvement in IIEF from V1 to V2 and V1 and V3, compared to those with mild-to-moderate IIEF scores. Both groups improved in SDS index from V1 to V2 and V1 to V3, with the greatest improvement between V1 and V3 for group 1 and V1 and V2 for group 2.Daily tadalafil 5 mg could be helpful for ED patients with depressive symptoms and improved LUTS and quality of life.

Attenuation of Benign Prostatic Hyperplasia by Optimized Tadalafil Loaded Pumpkin Seed Oil-Based Self Nanoemulsion: In Vitro and In Vivo Evaluation

The FDA has approved tadalafil (TDL) for the treatment of benign prostatic hyperplasia (BPH)-associated symptoms. Pumpkin seed oil (PSO) has shown promise for the relief of prostatitis-related lower urinary tract symptoms. The aim was to improve TDL delivery to the prostate and assess the combined effect of TDL with a PSO-based formula in the management of BPH. PSO, Tween 80, and polyethylene glycol 200 were selected for the optimization of self nano-emulsified drug delivery system (SNEDDS). The formed vesicles were assessed for their globule size and zeta potential. A rat in vivo study was carried out to investigate prostate weight and index, histopathology, and pharmacokinetics. The average globule size for the optimized TDL-PSO SNEDDS was 204.8 ± 18.76 nm, with a zeta-potential value of 7.86 ± 1.21 mV. TDL-PSO SNEDDS produced a marked drop in prostate weight by 35.51% and prostate index by 36.71% compared to the testosterone-only group. Pharmacokinetic data revealed a 2.3-fold increase of TDL concentration, from optimized TDL-PSO SNEDDS, in the prostate compared with the raw TDL group. This study indicated that the combination of TDL and PSO in an optimized TDL PSO SNEDDS formula improved the efficacy of TDL in the management of BPH.

Phosphodiesterase inhibitors say NO to Alzheimer's disease

Phosphodiesterases (PDEs) consisted of 11 subtypes (PDE1 to PDE11) and over 40 isoforms that regulate levels of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), the second messengers in cell functions. PDE inhibitors (PDEIs) have been attractive therapeutic targets due to their involvement in diverse medical conditions, e.g. cardiovascular diseases, autoimmune diseases, Alzheimer's disease (AD), etc. Among them; AD with a complex pathology is a progressive neurodegenerative disorder which affect mostly senile people in the world and only symptomatic treatment particularly using cholinesterase inhibitors in clinic is available at the moment for AD. Consequently, novel treatment strategies towards AD are still searched extensively. Since PDEs are broadly expressed in the brain, PDEIs are considered to modulate neurodegenerative conditions through regulating cAMP and cGMP in the brain. In this sense, several synthetic or natural molecules inhibiting various PDE subtypes such as rolipram and roflumilast (PDE4 inhibitors), vinpocetine (PDE1 inhibitor), cilostazol and milrinone (PDE3 inhibitors), sildenafil and tadalafil (PDE5 inhibitors), etc have been reported showing encouraging results for the treatment of AD. In this review, PDE superfamily will be scrutinized from the view point of structural features, isoforms, functions and pharmacology particularly attributed to PDEs as target for AD therapy.

Effectiveness of the addition of tadalafil to tamsulosin in the treatment of acute urinary retention in patients with benign prostatic hyperplasia: A randomized clinical trial

INTRODUCTION

Acute urinary retention is one of the most significant complications of benign prostatic hyperplasia. Until now, standard treatments include catheterization and use of α-blockers. Tadalafil has been recently seen to also play a role in the treatment of urinary symptoms caused by benign prostatic hyperplasia. The aim of this study was to survey the addition of tadalafil to tamsulosin in the treatment of acute urinary retention in patients with benign prostatic hyperplasia.

MATERIALS AND METHODS

This is a randomized, double-blind placebo-controlled clinical trial. In all, 80 patients with benign prostatic hyperplasia-related acute urinary retention referred to the emergency department of the hospital were divided into two groups of 40 each and randomly assigned to receive either 0.4 mg tamsulosin plus placebo or 0.4 mg tamsulosin plus 10 mg tadalafil daily for 7 days. At the same first visit, the catheter was removed and the ability to void in 24 h and 1 week later was assessed in each group.

RESULTS

The differences in age, urine retention volume, history of drug use, lower urinary tract symptoms, and previous acute urinary retention were not significant between the two groups ( p = 0.619, 0.149, 0.501, 0.284, and 0.371, respectively). After catheter removal, 23 (57.5%) patients in the placebo group and 26 (65%) in the tadalafil group voided successfully at 24 h ( p = 0.491). After 1 week, 29 (72.5%) patients taking placebo and 26 (65%) taking tadalafil could void, yet indicating no significant difference ( p = 0.469).

CONCLUSION

Addition of tadalafil to α-blockers has no significant advantage in improving benign prostatic hyperplasia-related acute urinary retention versus tamsulosin alone.

From rapalogs to anti-aging formula

Inhibitors of mTOR, including clinically available rapalogs such as rapamycin (Sirolimus) and Everolimus, are gerosuppressants, which suppress cellular senescence. Rapamycin slows aging and extends life span in a variety of species from worm to mammals. Rapalogs can prevent age-related diseases, including cancer, atherosclerosis, obesity, neurodegeneration and retinopathy and potentially rejuvenate stem cells, immunity and metabolism. Here, I further suggest how rapamycin can be combined with metformin, inhibitors of angiotensin II signaling (Losartan, Lisinopril), statins (simvastatin, atorvastatin), propranolol, aspirin and a PDE5 inhibitor. Rational combinations of these drugs with physical exercise and an anti-aging diet (Koschei formula) can maximize their anti-aging effects and decrease side effects.

Changes in Erectile Function after Photoselective Vaporization of the Prostate with a 120-W GreenLight High-Performance System Laser: 2-Year Follow-Up

Purpose

To evaluate the impact of photoselective vaporization of the prostate (PVP) with a 120-W GreenLight high-performance system on erectile function in a 2-year follow-up study.

Materials and Methods

One hundred seventy-seven patients who underwent PVP during 2008 to 2012 were analyzed retrospectively. The patients were divided into 5 groups according to their preoperative 5-item International Index of Erectile Function (IIEF-5) scores: Group I (IIEF-5: 5~7, n=28), II (IIEF-5: 8~11, n=47), III (IIEF-5: 12~16, n=43), IV (IIEF-5: 17~21, n=34), and V (IIEF-5: 22~25, n=25). The patients were assessed before surgery and 6, 12, and 24 months after the PVP. Their International Prostate Symptom Score/quality of life, maximum urinary flow rate/post-void residual urine volume, and IIEF-5 scores were measured at each visit.

Results

The mean age and presence of hypertension were significantly different among the 5 groups. Perioperative parameters and postoperative complication rates showed no statistical differences. After PVP, voiding parameters were significantly improved in all the groups and sustained during the 2-year follow-up. The postoperative IIEF-5 scores fell slightly overall, while group V showed the largest significant deterioration. In multivariate analysis, body mass index (BMI) was the only independent predictor of decreased erectile function after PVP.

Conclusions

Erectile function declined in all the groups after PVP, with the most extensive deterioration observed in patients with normal erectile function preoperatively. Preoperative BMI was the only independent risk factor for a meaningful decrease in erectile function after PVP.

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.

The Wonders of Phosphodiesterase-5 Inhibitors: A Majestic History

The Nobel Prize winning discovery of nitric oxide (NO) in 1986 was the starting point for a new innovation in drug discovery. NO acting as a mediator at different physiological systems is believed to be involved in many physiological and pathological conditions through the formation of the second messenger cyclic guanosine monophosphate (cGMP). cGMP-dependent vasodilation effect of NO is important in regulating pulmonary and systemic pressures, maintaining penis erection, preventing atherosclerosis, preventing platelet aggregation, and protecting and controlling cardiac functions. The main enzyme involved in the termination of cGMP effects is phosphodiesterase enzyme 5 (PDE-5), which is overexpressed in ventricular hypertrophy and heart failure. A milestone in drug discovery was the selective inhibitors of PDE-5 that developed to be a multibillion dollar blockbuster in drug market. PDE-5 inhibitors are approved for the treatment of erectile dysfunctions (EDs), pulmonary hypertension, and benign prostatic hypertrophy. They are also under clinical trials for their cardiac protection against damage induced by ischemia or heart failure. This review article is an update about the pharmacotherapeutics of PDE-5 inhibitors and the majestic history that led to their discovery. The information reported in this review was obtained from the electronic sources of different databases such as PubMed Central, Google Scholar, and Scopus. Keywords used for search included cGMP (mechanisms and functions), EDs (drugs used), nitric oxide, and PDE-5 inhibitors (clinical applications). A total of 165 articles were studied, of which 45 articles were referred to in this review.

Elucidation of the Pattern of the Onset of Male Lower Urinary Tract Symptoms Using Cluster Analysis: Efficacy of Tamsulosin in Each Symptom Group

OBJECTIVE

To present a new grouping of male patients with lower urinary tract symptoms (LUTS) based on symptom patterns and clarify whether the therapeutic effect of α1-blocker differs among the groups.

METHODS

We performed secondary analysis of anonymous data from 4815 patients enrolled in a postmarketing surveillance study of tamsulosin in Japan. Data on 7 International Prostate Symptom Score (IPSS) items at the initial visit were used in the cluster analysis. IPSS and quality of life (QOL) scores before and after tamsulosin treatment for 12 weeks were assessed in each cluster. Partial correlation coefficients were also obtained for IPSS and QOL scores based on changes before and after treatment.

RESULTS

Five symptom groups were identified by cluster analysis of IPSS. On their symptom profile, each cluster was labeled as minimal type (cluster 1), multiple severe type (cluster 2), weak stream type (cluster 3), storage type (cluster 4), and voiding type (cluster 5). Prevalence and the mean symptom score were significantly improved in almost all symptoms in all clusters by tamsulosin treatment. Nocturia and weak stream had the strongest effect on QOL in clusters 1, 2, and 4 and clusters 3 and 5, respectively.

CONCLUSION

The study clarified that 5 characteristic symptom patterns exist by cluster analysis of IPSS in male patients with LUTS. Tamsulosin improved various symptoms and QOL in each symptom group. The study reports many male patients with LUTS being satisfied with monotherapy using tamsulosin and suggests the usefulness of α1-blockers as a drug of first choice.

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.