Evidence for the efficacy and safety of tadalafil and finasteride in combination for the treatment of lower urinary tract symptoms and erectile dysfunction in men with benign prostatic hyperplasia

A prospective, randomized, open-label, parallel trial comparing the efficacy of α-blocker or 5α-reductase inhibitor withdrawal to continued combination therapy on the maintenance of lower urinary tract symptoms in men with benign prostatic hyperplasia

BACKGROUND

It is uncertain how long combination therapy should be continued in patients with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). We investigated the withdrawal effects of α1-adrenergic receptor blocker (AB) or 5α-reductase inhibitor (5ARI) following successful combination therapy.

METHODS

This prospective, randomized, open-label, parallel trial enrolled 222 patients with BPH/LUTS who showed at least a seven-point improvement in International Prostate Symptom Score-total (IPSS-T) and a ≥ 20% reduction in prostate volume (PV) following the initiation of combination therapy. Patients were randomized in a 1:1:1 ratio into continued-combination, AB-withdrawal, and 5ARI-withdrawal groups. IPSS, overactive bladder symptom score, EuroQol-five-dimensional questionnaire (EQ-5D-5L), EuroQol-visual analog scale (EQ-VAS), prostate volume (PV), maximal flow rate, postvoid residual urine (PVR), and prostate-specific antigen level were assessed every 6 months for 24 months. The predictors of IPSS-T deterioration were evaluated.

RESULTS

At Month 24, IPSS-T deterioration (≥2 point) was observed in 20/72 (27.8%) and 19/72 (26.4%) patients in the AB- and 5ARI-withdrawal groups, respectively. Among them, 4/72 (5.6%) and 4/70 (5.7%) patients required readdition of the withdrawn drug (p = 0.868). In the continued combination group, EQ-VAS improved at Month 24 compared to baseline (p = 0.028). At Month 24, the AB-withdrawal group showed improvements in EQ-5D-5L, EQ-VAS, and PVR (all p < 0.005), while the 5ARI-withdrawal group showed improvement in IPSS-S (p = 0.011). Diabetes mellitus was associated with IPSS-T deterioration at Month 24 (p = 0.020).

CONCLUSIONS

In patients with BPH/LUTS who are reluctant to continue combination therapy, AB or 5ARI withdrawal may be offered in men with improvement in IPSS-T by at least seven points and reduction in PV by at least 20%.

Food Administration and Not Genetic Variants Causes Pharmacokinetic Variability of Tadalafil and Finasteride

Tadalafil and finasteride are used in combination for the management of benign prostatic hyperplasia (BPH). Genetic variations in genes involved in the metabolism and transport of tadalafil or finasteride (i.e., pharmacogenes) could affect their pharmacokinetic processes altering their drug exposure, efficacy, and toxicity. The main objective of this study was to investigate the effects of variants in pharmacogenes on the pharmacokinetics of tadalafil and finasteride. An exploratory candidate gene study involving 120 variants in 33 genes was performed with 66 male healthy volunteers from two bioequivalence clinical trials after administration of tadalafil/finasteride 5 mg/5 mg under fed or fasting conditions. Afterwards, a confirmatory study was conducted with 189 male and female volunteers receiving tadalafil 20 mg formulations in seven additional bioequivalence clinical trials. Regarding tadalafil, fed volunteers showed higher area in the time-concentration curve (AUC∞), maximum plasma concentration (Cmax), and time to reach Cmax (tmax) compared to fasting volunteers; male volunteers also showed higher AUC∞ and Cmax compared to female volunteers. Furthermore, fed volunteers presented higher finasteride AUC∞, Cmax and tmax compared to fasting individuals. Variants in ABCC3, CYP1A2, CES1, NUDT15, SLC22A1/A2 and UGT2B10 were nominally associated with pharmacokinetic variation in tadalafil and/or finasteride but did not remain significant after correction for multiple comparisons. Genetic variation did not demonstrate to clinically impact on the pharmacokinetics of finasteride and tadalafil; however, additional studies with larger sample sizes are needed to assess the effect of rare variants, such as CYP3A4*20 or *22, on tadalafil and finasteride pharmacokinetics.

Synchronous fluorescence as a green and selective method for the simultaneous determination of finasteride and tadalafil in dosage form and spiked human plasma

Finasteride and tadalafil are combined in a pharmaceutical capsules called Entadfi™, that has received FAD approval. It was indicated for the management of male benign prostatic hyperplasia-related urinary tract issues. In the current study, finasteride and tadalafil concentrations in raw form, laboratory prepared mixtures, pharmaceutical preparation and spiked human plasma were all quantitatively estimated using a sensitive synchronized fluorescence spectroscopic approach united with first derivative. When excited at 260 nm, finasteride display its emission at 320 nm. Yet, when excited at 280 nm, tadalafil displayed its emission at 340 nm. The application of micellar surfactant as sodium dodecyl sulphate (SDS) significantly increased the fluorescence intensity.The overlapping of the fluorescence spectra was entirely eliminated by derivatizing the synchronous spectra to the first derivative, which also made it possible to simultaneously quantify the cited drugs. Without interfering with one another, the first-order synchronous spectra of tadalafil and finasteride at 320 and 330 nm, respectively. The approach revealed linearity alongside an acceptable correlation coefficient for finasteride and tadalafil concentrations over the range of 10 -50 ng/mL. That approach was utilized to estimation of the cited drugs in dosage forms, simultaneously with %recoveries for tadalafil and finasteride of 99.62 ± 0.78 and 100.19 ± 0.60, respectively. Also, four various tools, the national environmental method index, the AGREE evaluation method, the green analytical procedure index and the analytical eco-scale were used to evaluate how environmentally friendly the given approach was. With regard to the metrics of the greenness aspects, the proposed approach appeared to be better than the previously published spectrophotometric methods and HPLC.

Development of a machine learning-based predictive model for prediction of success or failure of medical management for benign prostatic hyperplasia

OBJECTIVE

To develop a novel predictive model for identifying patients who will and will not respond to the medical management of benign prostatic hyperplasia (BPH).

METHODS

Using data from the Medical Therapy of Prostatic Symptoms (MTOPS) study, several models were constructed using an initial data set of 2172 patients with BPH who were treated with doxazosin (Group 1), finasteride (Group 2), and combination therapy (Group 3). K-fold stratified cross-validation was performed on each group, Within each group, feature selection and dimensionality reduction using nonnegative matrix factorization (NMF) were performed based on the training data, before several machine learning algorithms were tested; the most accurate models, boosted support vector machines (SVMs), being selected for further refinement. The area under the receiver operating curve (AUC) was calculated and used to determine the optimal operating points. Patients were classified as treatment failures or responders, based on whether they fell below or above the AUC threshold for each group and for the whole data set.

RESULTS

For the entire cohort, the AUC for the boosted SVM model was 0.698. For patients in Group 1, the AUC was 0.729, for Group 2, the AUC was 0.719, and for Group 3, the AUC was 0.698.

CONCLUSION

Using MTOPS data, we were able to develop a prediction model with an acceptable rate of discrimination of medical management success for BPH.

Simultaneous spectrophotometric determination of finasteride and tadalafil in recently FDA approved Entadfi™ capsules

Entadfi™ is a recently FDA approved pharmaceutical combination capsule of finasteride and tadalafil. It was prescribed for the treatment of urinary tract disorders caused by benign prostatic hyperplasia in men. This paper introduced the first spectrophotometric methods for simultaneous determination of finasteride and tadalafil in the pure form and in the pharmaceutical capsules. UV absorption spectra of finasteride and tadalafil exhibited overlap hindered the direct simultaneous determination of the cited drugs. The UV absorption spectra of finasteride and tadalafil were transformed to the second order derivative. Finasteride could be determined selectively at 230.80 nm without interference from tadalafil. Moreover, tadalafil could be determined selectively at 292 nm without interference from finasteride. The ratio spectra of the studied drugs were derived and the derived ratio spectra of each drug were transformed to the first order derivative. Finasteride could be determined selectively at 218.80 nm without interference from tadalafil. Moreover, tadalafil could be determined selectively at 289.60 nm without interference from finasteride. The methods showed linearity with an excellent correlation coefficient in the concentration range of 10-140 µg/mL for finasteride and 3-40 µg/mL for tadalafil. The methods were validated following ICH guidelines for accuracy, precision, robustness, limit of detection, limit of quantification, and selectivity. The methods were found to be sensitive with LOD values for finasteride and tadalafil of 2.406 µg/mL and 0.876 µg/mL using the second derivative with zero crossing method and 2.229 µg/mL and 0.815 µg/mL using the first derivative of ratio spectra method. The methods were successfully applied for the determination of the studied drugs in their laboratory prepared mixtures, with mean percent recovery for finasteride and tadalafil of 99.37% and 99.17% using the second derivative with zero crossing method and 99.74% and 99.56% using the first derivative of ratio spectra method. Furthermore, the described methods were successfully applied for determination of the studied drugs in Entadfi™ capsules without interference from excipients. Based on the proposed results, the described methods could be utilized as simple method for the quality control of the studied drugs.

Efficacy and Safety of Combination Comprising Tamsulosin and PDE5-Is, Relative to Monotherapies, in Treating Lower Urinary Tract Symptoms and Erectile Dysfunction Associated With Benign Prostatic Hyperplasia: A Meta-Analysis

We report safety and efficacy of a combination therapy, comprising tamsulosin and phosphodiesterase type 5 inhibitors (PDE5-Is), relative to monotherapy, to ascertain its potential in treating lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) secondary to benign prostatic hyperplasia (BPH) after 3 months’ treatment. We screened MEDLINE, EMBASE, and the Cochrane Controlled Trials Register databases, for randomized controlled trials, and obtained eight articles comprising 1144 participants. Results showed that the combination group had superior outcomes with regard to International Prostate Symptom Score (IPSS) and Qmax, compared to the other two groups. The combination group also had superior efficacy with regard to International Index of Erectile Function (IIEF) than the tamsulosin group, but not over the PDE5-Is group. Further, the combination group showed better efficacy in IPSS voiding and quality of life (QoL) compared to the PDE5-Is group. An analysis of safety outcomes revealed extremely high adverse events (AEs) and pain in the combination group. However, therapy discontinuation due to pain and AEs did not increase with increase in AEs. Overall, our findings indicate that a combination of tamsulosin and PDE5-Is is superior to individual tamsulosin and PDE5-Is monotherapy, with regard to improving LUTS and ED secondary to BPH.

Management of benign prostate hyperplasia (BPH) by combinatorial approach using alpha-1-adrenergic antagonists and 5-alpha-reductase inhibitors

Currently, the main available treatments for benign prostate hyperplasia (BPH) are alpha-1 adrenergic receptor antagonists (ARAs), 5-alpha reductase inhibitors (5-αRI), anticholinergics, and Phosphodiesterase-5 inhibitors. Recent studies support the combined therapy approach using ARAs with 5-αRI for lower urinary tract symptoms (LUTS) in BPH patients at risk of clinical progression. We aimed to review BPH management in select group of randomized controlled trials by combination therapy with ARAs and 5-αRIs compared to monotherapy with either drug with respect to the safety and efficacy. A total of 6 randomized controlled trials (RCTs) involving comparison of combination therapy with monotherapy using ARAs and 5-αRIs were retrieved from PubMed Central and reviewed for international prostate symptom score (IPSS), quality of life (QoL), post-residual urinary flow rate (PUF), and clinical progression. The results significantly favour the treatment group that received the combination therapy in comparison with the groups receiving monotherapy. However, outcome with regard to prostate volume showed insignificant improvement when the combination therapy is compared with 5- αRIs alone, rather than ARAs. In conclusion, combination therapy using ARAs and 5-αRI is better than monotherapy in the patients of BPH. Fixed dose combination (FDC), a type of combination, is also cost-effective and its side-effects profile resembles to that of monotherapy.

Should All Men with Type 2 Diabetes Be Routinely Prescribed a Phosphodiesterase Type 5 Inhibitor?

Important health problems in men such as type 2 diabetes (T2DM), insulin resistance, erectile dysfunction, benign prostatic hyperplasia and depression have been shown to have to share common pathological processes, such as endothelial dysfunction and inflammation. This paper discusses the role of phosphodiesterase type 5 (PDE5) inhibitors, through beneficial effects on endothelial function and mediators of chronic inflammation and the possibility to treat or preventing these common conditions. We explore possible barriers to this approach, namely the lack of multiple product licences to treat each of these conditions and how these can be overcome by involving the patient in personalised decisions. We also discuss how opportunities are lost by patients with multiple medical conditions being referred to specialists, primarily interested in one specific problem, with little motivation to treat or prevent conditions outside their remit. We explore how these problems might be related to time and financial restraints or simply a lack of awareness of evidence published in journals related to other specialities. As specialists, we often pride ourselves on providing "personalised" or "patient centred" care, but we can only truly be doing so if we assess the specific needs of the patient across a range of conditions. As part of personalised care in T2DM, we routinely prescribe statins, angiotensin converting enzyme inhibitors and metformin, often with poor compliance. In this paper we explore whether the licensed daily PDE5 inhibitor tadalafil should be added routinely to this list as it will potentially improve and prevent bothersome symptoms and improve compliance with other medications.

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.

Benign prostatic hyperplasia after prostatic arterial embolization in a canine model: A 3T multiparametric MRI and whole-mount step-section pathology correlated longitudinal study

PURPOSE

To explore the morphological and functional characteristics of prostatic arterial embolization (PAE) in a canine model of benign prostatic hyperplasia (BPH) with 3T multiparametric magnetic resonance imaging (mp-MRI) and whole-mount step-section pathology correlation.

MATERIALS AND METHODS

Eight adult male beagle dogs with hormone-induced BPH underwent 3T mp-MRI before and 1, 3, and 6 months after PAE, with subsequent whole-mount step-section pathologic assessment. Images were acquired using T₁ -weighted images (T₁ WI), T₂ WI, 3D-SPACE, diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), T₂ -mapping, and dynamic contrast-enhanced (DCE) sequences. Variance analysis was performed to assess statistical differences in prostatic volume (PV), apparent diffusion coefficient (ADC), and T₂ values. Pearson correlation analysis was performed to correlate ADC, T₂ , and PV.

RESULTS

The PV decreased from baseline to 1, 3, and 6 months after PAE from (25.88 ± 7.09) cm³ to (6.48 ± 2.08) cm³ , (6.48 ± 3.39) cm³ , (6.20 ± 2.88) cm³ . The ADC values sequentially decreased from baseline to 1, 3, and 6 months after PAE from (1497.06 ± 222.72) × 10^-6 mm² /s to (1056.00 ± 189.46) × 10^-6 mm² /s, (950.48 ± 77.85) × 10^-6 mm² /s, (980.98 ± 107.78) × 10^-6 mm² /s. The T₂ values decreased from baseline to 1, 3, and 6 months after PAE were (83.74 ± 5.29) msec, (68.72 ± 5.66) msec, (53.96 ± 15.04) msec, (49.81 ± 13.34) msec, respectively. ADC and T₂ values were positively correlated with PV (r = 0.823 and 0.744, respectively). Microhemorrhages and hemosiderin were found on SWI after PAE.

CONCLUSION

3T mp-MRI may facilitate noninvasive assessment of morphological and functional changes of BPH after PAE.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1220-1229.