Stability Indicating RP-HPLC-DAD method for simultaneous estimation of tadalafil and macitentan in synthetic mixture for treatment of pulmonary arterial hypertension

OBJECTIVE

High Performance liquid chromatography is an integral analytical tool in assessing drug product stability. A simple, selective, precise, accurate and stability indicating RP-HPLC method was developed and validated for analysis of Tadalafil and Macitentan in synthetic mixture.

MATERIAL AND METHOD

Chromatographic separation was performed using Phenomex Gemini C18 (25cm×4.6nm, 5μm) Column. The mobile phase consists of (10mM Ammonium Acetate in water and [Methanol: ACN 20: 80% v/v]) (40: 60% v/v). The flow rate was set to be 1.0mL/min. The injection volume was 10.00μL. The detection was carried out at 260nm at column temperature 35°C.

RESULTS

The method was validating according to ICH Q2R1 guideline for accuracy, precision, reproducibility, specificity, robustness and detection and quantification limits. Stability testing was performed on Tadalafil and Macitentan and it was found that these degraded sufficiently in all applied chemical and physical conditions. Linearity for Tadalafil and Macitentan was observed 0.4-100μg/mL and 0.1-25μg/mL with correlation coefficient at 0.9999. LOD and LOQ 0.008μg/mL and 0.024μg/mL and 0.001μg/mL and 0.0029μg/mL for Tadalafil and Macitentan respectively.

CONCLUSION

The developed RP-HPLC method was found to be suitable for the determination of both the drugs.

Investigating in-vitro functionality and in-vivo taste assessment of eco-friendly Tadalafil Pastilles

Tadalafil (TDL) has poor bioavailability due to the less aqueous solubility and bitter taste. Oral solid dosage forms, especially tablets, have a broad market worldwide. Constraints of tablets are a long process, pollution, high processing cost, and requiring more excipient. The research was performed to optimize an eco-friendly immediate-acting pastille of TDL to put forward an alternate formulation to a tablet using advanced data mining tools. Another objective is to assess the taste masking of TDL using the Brief Access Taste Aversion (BATA) model. The amount of PEG-4000, Polyox N-10, and Kyron T-314 were chosen as critical material attributes from failure mode effect analysis. Box-Behnken design (BBD) was utilized to optimize the pastilles and ascertained the significant impact of chosen variables on disintegration time and % CDR at 10 min. The control strategy and optimal region were located using an overlay plot. The pastilles were able to release the drug within 15 min due to faster disintegration. The formulated pastilles were of uniform size, shape, and mechanical strength. The bitter taste of TDL was masked and confirmed by the BATA model. The newer formulation may be helpful in the industry due to its eco-friendly, single-step, and economical process. It unlocks a new direction in the field of oral solid dosage form as an alternative to tablets.

Placenta-anchored tadalafil liposomes rescues intrauterine growth restriction through continuous placental blood perfusion improvement

Physiological or pathological hypoperfusion of the placenta is one of the main causes of intrauterine growth restriction (IUGR) which poses a significant risk to the health of the fetus and newborn. Tadalafil, a 5-type phosphodiesterase inhibitor, has previously been found to improve the symptoms of IUGR in various clinical studies. Unfortunately, its clinical utility is hindered by its limited water solubility, rapid metabolism, and lack of specific distribution in target tissues rendering tadalafil unable to maintain long-term placental perfusion. In this study, iRGD-modified tadalafil-loaded liposomes (iRGD-lipo@Tad) featuring a size of approximately 480 nm were designed to rectify the shortcomings of tadalafil. The prepared iRGD-lipo@Tad exhibited superior stability, sustained drug release capacity, and low cytotoxicity. The fluorescence study, tissue slice study, and drug biodistribution study together demonstrated the placenta-anchored ability of iRGD-modified liposomes. This was achieved by a dual approach consisting of the iRGD-mediated placenta-targeting effect and special particle size-mediated placenta resident effect. The pharmacokinetic study revealed a significant improvement in the in vivo process of tadalafil encapsulated by the iRGD-modified liposomes. In comparison to the tadalafil solution, the peak plasma concentration of iRGD-lipo@Tad was significantly increased, and the area under the curve was increased by about 7.88 times. In the pharmacodynamic study, iRGD-lipo@Tad achieved a continuous and efficient improvement of placental blood perfusion. This was achieved by decreasing the ratio of plasma soluble fms-like tyrosine kinase to placental growth factor and increasing the levels of cyclic guanosine monophosphate and nitric oxide. Consequently, iRGD-lipo@Tad resulted in a significant increase in embryo weight and a reduction in the miscarriage rate of N-Nitro-L-arginine methyl ester-induced IUGR pregnant mice without detectable toxicity. In summary, the nanotechnology-assisted therapy strategy presented here not only overcomes the limitations of tadalafil in the clinical treatment of IUGR but also offers new avenues to address the treatment of other placenta-originated diseases.

Evaluation of tadalafil supplementation on the neutrophil/lymphocyte and the platelet/lymphocyte ratios in patients with erectile dysfunction: A prospective study

OBJECTIVES

We aimed to evaluate the effect of daily 5 mg tadalafil on the neutrophil/lymphocyte ratio (NLR) and the platelet/lymphocyte ratio (PLR) in patients with erectile dysfunction (ED).

PATIENTS AND METHODS

30 subjects with ED were given tadalafil as well as 30 subjects with ED who were not receiving tadalafil were recruited. 30 healthy individuals served as controls.

RESULTS

Receiver operating characteristic curve (ROC) showed that the best cut off point of pre-treatment and post treatment NLR in the ED treatment group was found <1.51, <1.51, sensitivity of 68.3%, 58.3%, specificity of 53.3%, 53.3%, lower bound of 0.558, 0.517, upper bound of 0.789, 0.757, total accuracy of 67.4%, 63.7% and p 0.003, 0.0025, respectively. Additionally, the best cut off point of pre-treatment and post treatment PLR in the ED treatment group was found <5.89, <5.99, sensitivity of 65%, 63.3%, specificity of 63.3%, 53.3%, lower bound of 0.515, 0.435, upper bound of 0.755, 0.687, total accuracy of 63.5%, 56.1% and p 0.027, 0.341, respectively.

CONCLUSION

Daily 5 mg Tadalafil supplementation significantly improves erectile function through decreasing these markers as well as depression and anxiety.

Choc-Tadalafil Fusion: Unlocking Solubility and Taste Harmony with ß-CD-Infused Medicated Chocolate

OBJECTIVE

The primary limitations of tadalafil in treating erectile dysfunction are its low solubility and unpleasant bitter taste, which ultimately result in inadequate patient adherence. The present study aimed to develop and characterize a medicated chocolate formulation containing Tadalafil and ß-CD (solubility enhancer) employing the concept of Design of Experiment (DoE) using chocolate as a user-friendly excipient.

METHODS

An inclusion complex was formulated by incorporating the drug into ß-CD using the kneading method for solubility improvement and also as a taste masker for Tadalafil. The ratio of drug: ß-CD inclusion complex was selected based on a phase solubility study. The inclusion complex was molded into a chocolate base and optimized using the DoE approach. Further, drug excipient interaction was evaluated by DSC and FTIR study.

RESULT

Phase solubility study suggested a 1:1 ratio of Tadalafil: β-CD for better solubility. DSC spectra suggested the conversion of crystalline structure into an amorphous state which indicates improvement of the drug solubility. DSC and FTIR studies revealed that there was no significant interaction between drug and excipients. Next, %CDR (cumulative drug release) at 30 min revealed the immediate effect of Tadalafil from chocolate formulation and free drug analysis (an unbound drug with ß-CD) proved reduced bitterness of the drug in the complex. Additionally, the medicated chocolate was found to be stable at room temperature as per stability study.

CONCLUSION

β-CD was found to be a promising multifunctional excipient as a solubility enhancement carrier and taste masker for bitter-tasting drugs.

Comparison of the effect of hyperbaric oxygen therapy and tadalafil daily use on erectile function: a prospective, double controlled study

PURPOSE

Erectile dysfunction (ED) is a worldwide health problem. Oral phosphodiesterase type 5 inhibitors (PDE5I) are used in its first-line treatment. This study aimed to compare the effects of hyperbaric oxygen (HBO) treatment with PDE5I treatment and determine the patient-dependent factors affecting the efficacy of the HBO treatment and duration of action of HBO treatment.

METHODS

Adult male patients who presented to the HBO unit for HBO treatment with non-urological indications and had ED based on the International Index for Erectile Function (IIEF-5) constituted the target population of this study. Participants were given HBO treatment (Group 1), no treatment (Group 2), or daily oral tadalafil 5 mg treatment (Group 3). The treatment duration was 1 month. Patients were assessed by IIEF-5 both initially and after the completion of 1 month.

RESULTS

There were significant increases in the mean IIEF-5 scores of the patients in Group 1 and Group 3 (p < 0.001, p < 0.001). However, there was no significant improvement in Group 2 (p = 0.496). Also, the post-treatment IIEF-5 scores of Group 1 and Group 3 were significantly higher than Group 2 (p < 0.001). There was no significant difference between the IIEF-5 scores and ∆IIEF-5 values of Group 1 and Group 3 (p = 0.166, p = 0.093). Evaluation regarding comorbidities revealed that patients with the peripheral vascular disease did not improve with HBO treatment (p = 0.285).

CONCLUSION

HBO can improve erectile functions, and it can be a reasonable alternative for patients who cannot use PDE5Is due to comorbidities or treatment side effects.

Single-dose Tadalafil Reduces Opening Urethral Pressure: A Randomized, Double-blind, Placebo-controlled, Crossover Trial in Healthy Women

INTRODUCTION AND HYPOTHESIS

Phosphodiesterase enzymes are widely distributed in female urogenital tissues. Yet, the understanding of their physiological roles and the impact of phosphodiesterase inhibitors on lower urinary tract symptoms in women remains limited. Current hypotheses are conflicting: one suggests that vasodilation might expand the periurethral vascular plexus, leading to increased urethral pressure, whereas the other proposes a relaxation of urethral musculature, resulting in decreased pressure. To further clarify this, we investigated the effect of tadalafil on the opening urethral pressure and voiding function in healthy women.

METHODS

We conducted a randomized, double-blind, placebo-controlled crossover trial involving 24 healthy women. Participants were randomly assigned to receive a single dose of tadalafil (40 mg) or placebo during their initial visit and then switched to the alternative treatment during their second visit. Opening urethral pressure was measured with urethral pressure reflectometry during both resting and squeezing conditions of the pelvic floor. Subsequently, voiding parameters were recorded.

RESULTS

Compared with placebo, a single dose of tadalafil significantly reduced opening urethral pressure during both resting (-6.8 cmH20; 95% confidence interval [CI], -11.8 to -1.9; p = 0.009) and squeezing conditions (-8.8 cmH20; 95% CI, -14.6 to -3.1; p = 0.005). Voiding parameters did not show significant differences (average flow rate: -0.8 ml/s [95% CI, -2.0 to 0.4; p = 0.2]; maximum flow rate: -1.7 ml/s [95% CI, -4.8 to 1.5; p = 0.3]).

CONCLUSIONS

A single dose of 40 mg tadalafil moderately reduced urethral pressure in healthy women, without affecting voiding parameters. The clinical implications of this are yet to be determined.

Novel drug therapy of acute hepatic failure induced in rats by a combination of tadalafil and Lepidium sativum

BACKGROUND

Hepatocyte death and a systemic inflammatory response are the outcome of a complex chain of events mediated by numerous inflammatory cells and chemical mediators. The point of this study was to find out if tadalafil and/or Lepidium sativum (L. sativum) could help people who have been exposed to carbon tetrachloride (CCL4) and are experiencing acute moderate liver failure. This was especially true when the two were used together.

METHOD AND MATERIALS

To cause mild liver failure 24 h before sacrifice, a single oral dosage of CCL4 (2.5 mL/kg b.w.) (50% in olive oil) was utilized. Furthermore, immunohistochemical expression of nuclear factor kappa B (NF-κB) as well as histological abnormalities were performed on liver tissue.

RESULTS

The results showed that tadalafil and/or L. sativum, especially in combination, performed well to cure acute mild liver failure caused by CCL4. This was demonstrated by a decrease in NF-κB expression in the liver tissue and an improvement in organ damage markers observed in the blood and liver tissues. Furthermore, such therapy reduced interleukin1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) levels in the liver tissue. It's worth noting that the tested combination resulted in greater liver improvement.

CONCLUSIONS

According to the findings, tadalafil and L. sativum, particularly in combination, have the ability to protect the liver from the negative effects of CCL4 exposure. Because of its capacity to improve liver function, restore redox equilibrium, and decrease inflammatory mediators, it is a prospective option for mitigating the negative effects of common environmental pollutants such as CCL4.

Tadalafil versus tamsulosin as combination therapy with 5-alpha reductase inhibitors in benign prostatic hyperplasia, urinary and sexual outcomes

PURPOSE

To compare the urological and sexual outcomes of using either tamsulosin/finateride or tadalafil/finasteride as combination therapies in patients with large prostate.

PATIENTS AND METHODS

Selection criteria included prostate volume > 40 ml and IPSS > 7. Patients with severe erectile dysfunction (IIEF-erectile functions ≤ 10) were excluded. Patients were randomized into group I (tamsulosin/finasteride) and group II (tadalafil/finasteride). The primary endpoint was to define urinary and sexual function changes (IPSS, IPSS-quality of life, urinary flow rates and IIEF domains) within each group. The secondary endpoint was to compare the treatment induced changes between both groups.

RESULTS

At 4th and 12th weeks, 131 and 127 patients were available in both groups, respectively. Both groups showed significant LUTS improvement (IPSS changes: - 4.9 ± 2.7 and - 4.3 ± 2.9 at 4th week and - 6.1 ± 3 and - 5.4 ± 2.8 points by the 12th week in both groups, respectively). Group I had better average flow rates at both follow-up visits. Meanwhile, maximum flow rates were comparable in both groups at 12th week (13.5 ± 3.9vs. 12.6 ± 3.7, p > 0.05). In group I, all IIEF domains were significantly lowered at both visits (p < 0.05). Group II showed significant increase in IIEF-erectile function scores (1.3 ± 1.1 and 1.8 ± 1.2 at the 4th and 12th weeks) with a transient significant reduction of IIEF-orgasm and sexual desire noted only by the 4th week (- 0.8 ± 0.4 and - 0.6 ± 0.4, respectively).

CONCLUSION

Within three months, both combinations are comparably effective in improving BPH related LUTS. Tamsulosin/finasteride provided significantly better Qmax only at 4th week. Tadalafil/finasteride had the advantage of improving sexual performance over the other combination.

Efficacy of low-intensity shockwave therapy with different tadalafil regimens in patients with PDE5 inhibitor-resistant erectile dysfunction: a retrospective cohort study

PURPOSE

Currently, there is a lack of research comparing tadalafil treatment protocols recommended during low-intensity shock wave therapy (LI-SWT) for patients with erectile dysfunction (ED) who are unresponsive to phosphodiesterase type 5 inhibitors (PDE5i). The objective of this study is to compare the efficacy of only LI-SWT versus LI-SWT plus 5 mg tadalafil daily versus LI-SWT plus 20 mg tadalafil alternate-day in PDE5i -resistant ED. MATERıALS AND METHODS: In this study, a cohort of 105 patients with PDE5i-resistant ED was recruited and divided into three groups labeled as A (only LI-SWT), B (LI-SWT plus 5 mg tadalafil daily), and C (LI-SWT plus 20 mg tadalafil alternate-day), comprising 27, 42, and 36 patients, respectively. The patients' International Index of Erectile Function-5 (IIEF-5) scores and the Erection Hardness Score (EHS) were evaluated at the baseline, three months and six months following the treatment.

RESULTS

After three months post-treatment, the IIEF-5 scores in group A, B, and C increased by 4.1 ± 0.6, 7.3 ± 0.6, and 8.2 ± 0.6, respectively. These improvements were maintained at six months with IIEF-5 scores increasing by 3.7 ± 0.6, 7.3 ± 0.6, and 8.5 ± 0.7 in groups A, B, and C, respectively. At 3 and 6 months post-treatment, groups B and C showed significant improvement in IIEF-5 scores and EHS values compared to group A (p < 0.001). The rate of patients with EHS ≥ 3 and IIEF-5 ≥ 17 was significantly higher in groups B and C compared to group A, while there was no significantly different between groups B and C. CONCLUSıON: In patients with PDE5i-resistant ED, PDE5i combined with LI-SWT is superior to LI-SWT monotherapy. The statistical analysis failed to demonstrate any difference between two distinct tadalafil regimens when administered with LI-SWT treatment.

Two-dimensional phase-contrast MRI reveals changes in uterine arterial blood flow in pregnant women administered tadalafil for fetal growth restriction

INTRODUCTION

We aimed to examine the effect of uterine arterial (UtA) blood flow changes after tadalafil treatment for fetal growth restriction (FGR) using two-dimensional (2D) phase-contrast magnetic resonance imaging (PC-MRI).

METHODS

We recruited 14 pregnant women with FGR aged 20-44 years, at ≥20 weeks' gestation, between May 2019 and July 2020. They underwent 2D PC-MRI for UtA blood flow measurement 3 days (interquartile range: 2-4) after diagnosis. This group (FGR group) was compared with 14 gestational age (GA)-matched healthy pregnant women (control group). Six patients in the FGR group received treatment with tadalafil administered at 20 mg twice daily after the first MRI until delivery. They underwent a second MRI a week later.

RESULTS

The median total UtA blood/body surface area was 420 mL/min/m2 (290-494) in the FGR group and 547 mL/min/m2 (433-681) in the control group (p = 0.01). Percent increase in blood flow were significantly different between the FGR cases treated with tadalafil and control at 15.8 % (14.3-21.3) and 4.2 % (3.6-8.7), respectively (p = 0.03).

DISCUSSION

UtA blood flow in pregnant women with FGR was significantly lower than that in healthy pregnant women. Tadalafil is expected to improve UtA blood flow, thereby improving placental function in pregnant patients with FGR.

Breast Cancer Resistance Protein Limits Fetal Transfer of Tadalafil in Mice

Tadalafil, a phosphodiesterase 5 (PDE5) inhibitor, is a candidate therapeutic agent for fetal growth restriction and hypertensive disorders of pregnancy. In this study, we elucidated the fetal transfer of tadalafil in comparison with that of sildenafil, the first PDE5 inhibitor to be approved. We also examined the contributions of multidrug resistance protein 1 (MDR1) and breast cancer resistance protein (BCRP) to fetal transfer. Tadalafil or sildenafil was administered to wild-type, Mdr1a/b-double-knockout or Bcrp-knockout pregnant mice by continuous infusion from gestational day (GD) 14.5 to 17.5, and the fetal-to-maternal plasma concentration ratio of unbound drug (unbound F/M ratio) was evaluated at GD 17.5. The values of unbound F/M ratio of tadalafil and sildenafil in wild-type mice were 0.80 and 1.6, respectively. The unbound F/M ratio of tadalafil was increased to 1.1 and 1.7 in Mdr1a/b-knockout and Bcrp-knockout mice, respectively, while the corresponding values for sildenafil were equal to or less than that in wild-type mice, respectively. A transcellular transport study revealed that basal-to-apical transport of both tadalafil and sildenafil was significantly higher than transport in the opposite direction in MDCKII-BCRP cells. Our research reveals that tadalafil is a newly identified substrate of human and mouse BCRP, and it appears that the fetal transfer of tadalafil is, at least in part, attributed to the involvement of BCRP within the placental processes in mice. The transfer of sildenafil to the fetus was not significantly constrained by BCRP, even though sildenafil was indeed a substantial substrate for BCRP.

Sustainable UV approaches supported by greenness and whiteness assessments for estimating a recently FDA-approved combination for managing urologic disorders: Tukey's test

Erectile dysfunction caused by a urinary tract infection and an enlarged prostate is a common problem among men nowadays. A brand-new FDA-approved combination of finasteride (FNS) and tadalafil (TDF) is currently recommended, particularly for those with prostatic problems in addition to erectile dysfunction. TDF boosts FNS's short-term efficacy in addition to treating erectile dysfunction, one of the sexual adverse effects typically associated with FNS therapy. Accordingly, this research introduces three straightforward spectrophotometric techniques for determining FNS and TDF in their pure and pharmaceutical forms concurrently, in addition to providing a dissolution study for their formulation as per the FDA's directions. FNS and TDF have superimposed UV spectra, making direct concurrent analysis of these medications impossible. To resolve this overlap, we utilized the following UV techniques: the dual-wavelength method, the deconvoluted Fourier method, and the ratio difference method, with linear ranges of (0.50-15) µg/mL for TDF and (5-100) µg/mL for FNS. The LODs ranged from (0.12-0.15) µg/mL and (0.88-1.14) µg/mL, while the LOQs ranged from (0.37-0.46) µg/mL and (2.66-3.45) µg/mL for TDF and FNS, respectively. The proposed techniques were verified as per ICH recommendations and compared statistically to the published approach using three statistical tests. A complete green profile was provided to assess the foregoing techniques' greenness using four metrics, along with the whiteness assessment using the RGB algorithm. The foregoing UV methods have been demonstrated to be sustainable, highly sensitive, specific, and suitable for quality assurance testing.

Unusual cutaneous adverse reaction to an erectile dysfunction drug: A case report

We presents an unique and significant case of Acute Generalized Exanthematous Pustulosis (AGEP) associated with the use of tadalafil, a phosphodiesterase type 5 inhibitor for erectile dysfunction. AGEP, typically linked to antibiotics and antiepileptics, had not been previously reported with tadaladil in the MEDLINE database. The case involved a 40-year-old male who developed an erythematous rash, fever and sterile pustules after starting tadalafil. A skin biopsy confirmed AGEP. Discontinuation of the drug and treatment with prednsiolone cleared the dermatosis. This case emphasizes the need for awareness among healthcare providers regarding this potential adverse reaction, considering the growing use of tadalafil.

Development of a tadalafil transdermal formulation and evaluation of its ability to in vitro transdermal permeate using Strat-M® membrane

Tadalafil (TDF) has low water solubility, high intestinal permeability and belongs to the Biopharmaceutics Classification System (BCS) Class II. Due to high intestinal permeability, only oral administration (tablets) and oral thin film formulations have been developed. Therefore, it is necessary to develop various formulations, such as external formulations and transdermal absorption formulations requested by patients. The purpose of this study is to improve the solubility and skin permeability of TDF, and to develop a novel transdermal formulation with secured stability over time. The research strategy is to determine solvents that will improve TDF solubility and to screen substances that will enhance TDF permeability. Skin penetration tests were simulated by using a Strat-M® membrane in Franz diffusion cell systems. The optimal formulation (F1, consisting of TDF/HDTMA-Br at a ratio of 1:10 [weight/weight] in DPG) observed the highest permeability compared to all formulations in PBS (pH 7.4). Changes in thermal property of F1 formulation was observed and maintained its stability over 12 months including drug content (μg/mL), appearance, pH, and permeation (μg/cm2). In conclusion, DPG played a supported role in improving both TDF solubilization and permeability, whereas HDTMA-Br played a key role in enhancing permeability. It is thought that these results will be supplemented in the future to conduct research and experiments on humans.

Comparison of Monotherapies and Combination Therapy of Tamsulosin and Tadalafil for Treating Lower Urinary Tract Symptoms Caused by Benign Prostatic Hyperplasia with or without Erectile Dysfunction: A Meta-Analysis

BACKGROUND

There is limited research into the efficacy and safety of tadalafil combined with tamsulosin for the treatment of lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH), with or without erectile dysfunction (ED). Therefore, we aimed to investigate the efficacy and safety of combination therapy compared to that of monotherapy.

METHODS

We searched PubMed, Embase, Cochrane Library, Web of Science, SinoMed, CNKI, WanFang Data Service Platform, and ClinicalTrials.gov to identify eligible studies. A total of 639 articles were retrieved, of which 12 were randomized controlled trials (RCTs) published as of February 2023 and included in this meta-analysis.

RESULTS

After screening 639 articles, 12 RCTs including 1,531 subjects were considered eligible for the meta-analysis. The results showed that the total International Prostate System Score (total IPSS), maximum flow rate (Qmax), and quality of life (QoL) in tadalafil combined with tamsulosin were significantly better than those in monotherapy. Compared with tadalafil monotherapy, combination therapy mainly improved IPSS voiding. As for postvoid residual urine (PVR), the combination therapy did not improve PVR compared to the tadalafil group, but significantly improved PVR compared to the tamsulosin group. For the International Index of Erectile Function (IIEF), the curative effect of the combined group was better than that of the tamsulosin group but not better than that of the tadalafil group. In terms of safety, the adverse reactions (AEs) in the combined treatment group were significantly higher than those in the monotherapy group. None of the 12 RCTs reported serious adverse events.

CONCLUSIONS

Tadalafil combined with tamsulosin was more effective in the treatment of male LUTS/BPH, with or without ED, on the improvement of total IPSS, QoL, and Qmax. However, the benefits of combination therapy for ED remain unclear. However, combination therapy seemed to have a higher incidence of adverse reactions.

Phosphodiesterase-5 inhibitors tadalafil and sildenafil potentiate nitrergic-nerve mediated relaxations in the bladder vasculature

Recent studies suggest that lower urinary tract dysfunction may arise due to changes in local perfusion. Phosphodiesterase-5 inhibitors can improve urinary bladder blood flow, although the local mechanisms have not been fully elucidated. The aim was to pharmacologically characterise the vascular supply to the bladder and determine the mechanisms underlying the effects of the phosphodiesterase-5 inhibitors tadalafil and sildenafil. Responses of isolated rings of porcine superior vesical arteries to electrical field stimulation (EFS) were measured in the absence and presence of inhibitors of key neurotransmitter systems. Vasodilation responses to nitric oxide (NO) donors were also recorded, and the effects of phosphodiesterase-5 inhibitors on all responses determined. EFS caused biphasic responses with an initial vasoconstriction and a slower developing vasodilation. Vasoconstriction was mediated by ATP (55%) and noradrenaline (45%) release, whilst vasodilation was reduced by L-NNA (100 μM) (80%) and propranolol (1 μM) (20%). The nitrergic component was inhibited (81%) by L-NPA, a selective inhibitor of neuronal nitric oxide synthase (nNOS). Endothelial removal did not affect vasodilation. Tadalafil and sildenafil depressed noradrenaline-evoked vasoconstriction (by 26.8% and 35.5% respectively, P < 0.01), enhanced vasodilation to EFS (by 27.8% and 51.8% respectively, p < 0.01) and enhanced responses to NO donors nitroprusside, SIN-1, and SNAP, increasing pIC50 values (P < 0.01), without affecting maximal responses. In conclusion, neuronal NOS has a predominant role in regulating vascular tone of the porcine superior vesical artery and potentiation of nNO-mediated vasodilation is the primary mechanism underlying effects of phosphodiesterase-5 inhibitors in the bladder vasculature.

Efficacy of combination therapy tadalafil plus tamsulosin in ureteral stents-related symptoms relief

Introduction

Ureteral stents-related symptoms (USRs) are the common complications of ureteral stenting. Tamsulosin a selective alpha-1 blocker and Tadalafil a PDE-5 inhibitor are one of drugs have been used for USRs relief. In this study we aimed to evaluate the effectiveness and safety of combination therapy Tamsulosin+Tadalafil for treating USRs comparing it with the efficacy of either Tamsulosin or Tadalafil monotherapies.

Material and methods

279 patients with indwelled unilateral ureteral stents were randomized to Tamsulosin 0.4 mg + Tadalafil 5 mg once a day (Group 1, n = 67), Tamsulosin 0.4 mg once a day (Group 2, n = 71), Tadalafil 5 mg once a day (Group 3, n = 69) and Placebo once a day (Group 4, n = 72). USRs severity was registered and calculated by using the Ureteral Symptoms Score Questionnaire (USSQ) at the 14th day of treatment. Side-effects and total analgesic use were recorded and compared.

Results

At the endpoint in patients with unilateral ureteral stents the combination therapy Tamsulosin + Tadalafil led to statistically lower intensity of urinary symptoms comparing with Tamsulosin (15.2 ±4.3 vs 21.8±3.6, p = 0.0003) or Tadalafil (15.2 ±4.3 vs 20.6 ±2.8, p = 0.0004) monotherapy. All groups of treatment demonstrated significant relief of USRs comparing with Placebo mostly beneficial in the combined therapy group. Body pain and analgesic need in Group 1 was lower than in Groups 2, 3 or 4. Side-effects were registered rarely without statistical differences in frequency between groups.

Conclusions

Combination therapy with Tamsulosin + Tadalafil is an effective and safe option that achieves the statistically more significant relief of USRs comparing with Tadalafil or Tamsulosin monotherapies.

Clustering of Tadalafil API Samples According to their Manufacturer in the Context of API Falsification Detection

This paper reports the results of the active pharmaceutical ingredient (API) fingerprint study, organised by the General European Official Medicines Control Laboratory Network (GEON), on tadalafil. A classical market surveillance study, evaluating compliance to the European Pharmacopoeia, was combined with a fingerprint study, the latter to obtain characteristic data for the different manufacturers, allowing the network laboratories to conduct authenticity tests for future samples, as well as to detect substandard and falsified samples. In total, 46 tadalafil API samples from 13 different manufacturers were collected. For all samples fingerprint data was collected through analysis of impurities and residual solvents, mass spectrometric screening, X-ray powder diffraction and proton nuclear magnetic resonance (1H-NMR). Chemometric analysis revealed that all manufacturers could be characterised based on the impurity, residual solvent and 1H-NMR data. Future suspicious samples in the network will therefore be analysed with these techniques in order to attribute the sample to one of the manufacturers. If the sample cannot be attributed, a more profound investigation will be necessary to reveal the origin of the sample. In cases where the suspect sample is claimed to be from one of the manufacturers included in this study, analysis can be limited to the test distinguishing that manufacturer.

Tadalafil as medical expulsive therapy for distal ureteral stones: a systematic review and meta-analysis

PURPOSE

Medical expulsive therapy (MET) is recommended for distal ureteral stones from 5 to 10 mm. The best drug for MET is still uncertain. In this review, we aim to compare the effectiveness of tadalafil and tamsulosin for distal ureteral stones from 5 to 10 mm in terms of stone expulsion rate (SER), stone expulsion time (SET) and the side effect profile.

MATERIALS AND METHODS

A comprehensive literature search was conducted on MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Scopus and Web of Science, from inception until April 2023. Only randomized controlled trials were included in the analysis.

RESULTS

Eleven publications with 1,330 patients were included. We observed that tadalafil has a higher SER (OR 0.55, CI 95% 0.38;0.80, p=0.02, I2=52%) and the same efficacy in SET (MD 1.07, CI 95% -0.25; 2.39, p=0.11, I2=84%). No differences were found when comparing side effects as headache, backache, dizziness, and orthostatic hypotension.

CONCLUSION

Tadalafil has a higher stone expulsion rate than tamsulosin as a medical expulsive therapy for patients with distal stones from 5 to 10 mm without differences in side effects.

Effects of continuous use of Tadalafil on male sexual function after posterior urethroplasty: A clinical trial

INTRODUCTION

Posterior urethral injuries in men commonly occur following pelvic and perineal trauma. Erectile dysfunction (ED), whether brought on by the severity of the initial trauma or the surgery itself, is one of the complications in these patients.

MATERIALS AND METHODS

In this study, we divided candidates of posterior urethroplasty due to traumatic urethral injury into intervention and placebo groups; the former received continuous treatment with tadalafil (10 mg daily), and the latter received a placebo. Other services were provided equally to both groups. Before and after the intervention, both groups completed the International Index of Erectile Function version 5 (IIEF-5) questionnaire, and the findings were analyzed.

RESULTS

Forty patients were studied in groups of 20 with a mean age of 43.87 ± 15.70 years. The patient's most common cause of urethral injury was a pelvic fracture. Before the intervention, the mean scores of IIEF for patients in the intervention group and placebo group were 14.85 ± 7.39 and 14.77 ± 6.48, respectively with no statistical significance (p = 0.962) and patients of the groups were similar in terms of the severity of ED. The mean IIEF score in the intervention group was 20.12 ± 4.94 and in the placebo group, it was 18.05 ± 4.88 at the three-month follow-up, with no statistically significant difference (p = 0.063). In both the intervention and placebo groups, the IIEF score was significantly increased by 5.27 ± 4.04 (p < 0.001) and 3.27 ± 2.97 (p < 0.001), respectively. The rate of IIEF increase in the intervention group was higher than in the placebo group during the follow-up at 3-month follow-up with statistical significance. (p = 0.022).

CONCLUSION

The findings of this study suggest that tadalafil, in a 3-month treatment course, may improve erectile function in individuals with mild-to-moderate ED, significantly more than placebo. However, more studies, specifically with longer duration of follow-up and larger populations, are necessary for generalizing the current findings.

Regulation of renal nitric oxide and eNOS/iNOS expression by tadalafil participates in the mitigation of amphotericin B-induced renal injury: Down-regulation of NF-κB/iNOS/caspase-3 signaling

Amphotericin B (AmB)-induced acute kidney injury (AKI) is a common health problem having an undesirable impact on its urgent therapeutic utility for fatal systemic fungal infections. Tadalafil (TAD), a phosphodiesterase-5 (PDE-5) inhibitor, has been observed to have a wide range of pharmacological actions, including nephroprotection. The study's objective was to examine the possible underlying protective mechanism of TAD against AmB-induced nephrotoxicity. Experimentally, animals were divided randomly into four groups: control, TAD (5 mg/kg/day; p.o.), AmB (18.5 mg/kg/day; i.p.), and TAD+AmB groups. Sera and tissue samples were processed for biochemical, molecular, and histological analyses. The biochemical investigations showed that TAD significantly ameliorated the increase of kidney function biomarkers (creatinine, urea, CysC, KIM-1) in serum, renal nitric oxide (NO), lipid peroxidation (MDA), and inflammatory cytokines (TNF-α, IL-6) in AmB-treated rats. Meanwhile, TAD significantly retarded AmB-induced decrease in serum magnesium, sodium, potassium, and renal glutathione content. Molecular analysis revealed that TAD reduced AmB-induced imbalance in the protein expression of eNOS/iNOS, which explains its regulatory effect on renal NO content. These results were also supported by the down-regulation of nuclear NF-κB p65 and cleaved caspase-3 protein expressions, as well as the improvement of histological features by TAD in AmB-treated rats. Therefore, it can be suggested that TAD could be a promising candidate for renoprotection against AmB-induced AKI. That could be partly attributed to its regulatory effect on renal eNOS/iNOS balance and NO, the inhibition of NF-κB p65 nuclear translocation, its downstream inflammatory cytokines and iNOS, and ultimately the inhibition of caspase-3-induced renal apoptosis.

Neuropsychological secondary outcomes from the PASTIS trial

Cerebral small vessel disease (SVD) is a major cause of cognitive impairment in older people. As secondary endpoints in a phase-2 randomised clinical trial, we tested the effects of single administration of a widely-used PDE5 inhibitor, tadalafil, on cognitive performance in older people with SVD. In a double-blinded, placebo-controlled, cross-over trial, participants received tadalafil (20 mg) and placebo on two visits ≥ 7 days apart (randomised to order of treatment). The Montreal Cognitive Assessment (MOCA) was administered at baseline, alongside a measure to estimate optimal intellectual ability (Test of Premorbid Function). Then, before and after treatment, a battery of neuropsychological tests was administered, assessing aspects of attention, information processing speed, working memory and executive function. Sixty-five participants were recruited and 55 completed the protocol (N = 55, age: 66.8 (8.6) years, range 52-87; 15/40 female/male). Median MOCA score was 26 (IQR: 23, 27], range 15-30). No significant treatment effects were seen in any of the neuropsychological tests. There was a trend towards improved performance on Digit Span Forward (treatment effect 0.37, C.I. 0.01, 0.72; P = 0.0521). We did not identify significant treatment effects of single-administration tadalafil on neuropsychological performance in older people with SVD. The trend observed on Digit Span Forward may help to inform future studies.

Clinical trial registration

http://www.clinicaltrials.gov. Unique identifier: NCT00123456, https://eudract.ema.europa.eu. Unique identifier: 2015-001,235-20NCT00123456.

Predictors of the response to phosphodiesterase-5 inhibitors in pulmonary arterial hypertension: an analysis of the Spanish registry

BACKGROUND

Achieving and maintaining a low-risk profile is associated with favorable outcome in pulmonary arterial hypertension (PAH). The effects of treatment on risk profile are variable among patients.

OBJECTIVE

To Identify variables that might predict the response to treatment with phosphodiesterase-5 inhibitors (PDE-5i) in PAH.

METHODS

We carried out a cohort analysis of the Spanish PAH registry in 830 patients diagnosed with PAH that started PDE5i treatment and had > 1 year follow-up. 644 patients started PDE-5i either in mono- or add-on therapy and 186 started combined treatment with PDE-5i and endothelin receptor antagonist (ERA). Responders were considered when at 1 year they: (1) were alive; (2) did not present clinical worsening; and (3) improved European Society of Cardiology/European Respiratory Society (ESC/ERS) risk score or remained in low-risk. Univariate and multivariate logistic regression models were used to analyze variables associated with a favorable response.

RESULTS

Two hundred and ten patients (33%) starting PDE-5i alone were classified as responders, irrespective of whether it was mono- or add-on therapy. In addition to known predictors of PAH outcome (low-risk at baseline, younger age), male sex and diagnosis of portopulmonary hypertension (PoPH) or HIV-PAH were independent predictors of favorable response to PDE-5i. Diffusing capacity for carbon monoxide (DLco) ≤ 40% of predicted was associated with an unfavorable response. When PDE-5i were used in upfront combination, 58% of patients were responders. In this group, diagnosis of idiopathic PAH (IPAH) was an independent predictor of favorable response, whereas connective tissue disease-PAH was associated with an unfavorable response.

CONCLUSION

Male sex and diagnosis of PoPH or HIV-PAH are predictors of favorable effect of PDE-5i on risk profile when used as mono- or add-on therapy. Patients with IPAH respond more favorably to PDE-5i when used in upfront combination. These results identify patient profiles that may respond favorably to PDE-5i in monotherapy and those who might benefit from alternative treatment strategies.

Vasodilatory effects of tadalafil in an animal model of cerebral vasospasm: Comparative analysis with oral nimodipine

OBJECTIVES

Cerebral vasospasm is one of the most fatal complications after spontaneous aneurysmal subarachnoid hemorrhage. Although various treatments have been tried for the treatment of cerebral vasospasm so far, the effect is insignificant or temporary except for oral nimodipine. Phosphodiesterase isozyme type 5 inhibitor, which is used to treat erection dysfunction, recently has been known to have a cerebrovascular vasodilation. It is thought that this will be effective in cerebral vasospasm, and the effect will be compared and analyzed with oral nimodipine through an animal model of cerebral vasospasm.

MATERIAL AND METHODS

A total of 40 rabbits were used to make subarachnoid hemorrhage model and were divided into three groups - a control group, nimodipine group, and tadalafil group. The cerebral vessels were angiographically measured before and on the third day of subarachnoid hemorrhage. Then vertebrobasilar arteries were harvested and evaluated. Under the microscope, lumen area and media area were measured for each group and were compared.

RESULTS

Angiographically, tadalafil group showed significant vasodilation compared with the control group (p < 0.01). Histologically, tadalafil showed a similar effect on lumen and on media area to that of nimodipine group compared with the control group.

CONCLUSIONS

Cerebral vasospasm could leave neurologic deficit or sequelae even after proper treatment. Therefore, prevention is important. Tadalafil showed preventive effect against cerebral vasospasm and vasodilative effect similar to that of nimodipine. Therefore, tadalafil could be considered an alternative preventive treatment of cerebral vasospasm.

Successful delayed treatment of acute glans penis ischaemia after adult circumcision: a case report

Penile glans ischaemia post-circumcision is very rare. A 20-year-old male presented with glans ischaemia following an elective circumcision and was successfully treated with a combination of subcutaneous injection of low molecular weight heparin 0.5 mg·kg⁻¹ twice-daily, oral Tadalafil 5 mg once-daily for three days and 12 hyperbaric oxygen treatments at 243 kPa (2.4 atmospheres absolute) beginning 48 hours after the onset of ischaemia.

Phosphodiesterase 5 (PDE-5) inhibitors (sildenafil, tadalafil, and vardenafil) effects on esophageal motility: a systematic review

BACKGROUND

Esophageal motility disorders are a group of disorders associated with dysfunctional swallowing resulting from impaired neuromuscular coordination. Phosphodiesterase 5 (PDE-5) inhibitors induce smooth relaxation and are proposed as a treatment option for esophageal motility disorders such as achalasia.

METHODS

This study is conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We systematically searched MEDLINE/ PubMed, Scopus, EMBASE, and Web of Science databases for esophageal outcomes of individuals treated with PDE5 inhibitors. A random effect meta-analysis was conducted.

RESULTS

A total of 14 studies were included. They were conducted in different countries, with Korea and Italy having the highest number of articles. The main drug assessed was sildenafil. PDE-5 inhibitors resulted in a significant reduction in lower esophageal sphincter pressure (SMD - 1.69, 95% CI: -2.39 to -0.99) and the amplitude of contractions (SMD - 2.04, 95% CI: -2.97 to -1.11). Residual pressure was not significantly different between the placebo and sildenafil groups (SMD - 0.24, 95% CI: -1.20 to 0.72). Furthermore, a recent study reported contractile integral, stating that ingestion of sildenafil leads to a significant reduction in distal contractile integral and a significant increase in proximal contractile integral.

CONCLUSION

PDE-5 inhibitors significantly reduce LES resting pressure and esophageal peristaltic vigor, decreasing esophageal body contractility and contraction reserve. Therefore, using these drugs in patients affected by esophageal motility disorders may potentially improve their condition regarding symptom relief and prevention of further associated complications. Future reports investigating larger sample size is necessary in order to establish definite evidence regarding the efficacy of these drugs.

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 detector tube for screening tadalafil and its analogues in adulterated sexual enhancement products

Sexual enhancement products adulterated with phosphodiesterase 5 inhibitors (PDE-5i) pose a serious public health concern. Tadalafil and its analogues (Tds) are PDE-5i frequently detected as adulterants. In this study, a Td detector tube for the rapid detection of Tds was developed based on the color change reaction between sulfuric acid and Tds. The specificity of this test method was evaluated using 13 Tds, all of which elicited positive results. Additionally, 30 commonly found adulterants in dietary supplements, 11 active pharmaceutical ingredients of psychotropic drugs and 18 food ingredients were tested and obtained no false-positive results, except levomepromazine. The test tube accurately detected the presence or absence of Tds in 54 commercially available products. The visual detection limit was 2-50 and 5-20 μg/ml for Tds and tadalafil-spiked samples with matrix, respectively. The applicability of the developed detector tube to a semiquantitative test using digital image analyses were investigated using red, green, and blue color values. The results of the recovery test suggested that the tube test was affected by the dark-colored matrix. The results of semiquantitative analyses of tadalafil for five marketed products were consistent with the liquid chromatographic quantification results, except for the blue value. The detector tube developed in this study can facilitate with the rapid screening of Tds in adulterated sexual enhancement products.

The danger of hyperoxia on the rat kidneys: is tadalafil a real shield?

PURPOSE

Continuous oxygen therapy to compensate for decreased oxygen saturation in the blood is a life-saving treatment used in case lung involvement. Excess oxygen delivery was reported to be a common situation, in which about 50% of the patients showed hyperoxemia and 4% in severe hyperoxemia. In this work, we investigated the effects of hyperoxia on the rat kidneys and whether tadalafil has an effect to reduce this damage.

MATERIALS AND METHODS

Three groups of 8 male rats each weighing 300-350 g were formed. The groups were divided into the control group, hyperoxia group, and hyperoxia and tadalafil administered group for 10 days. At the end of the 10th day, blood and kidney samples were taken for biochemical analysis (SOD and NO levels) and histopathological examination.

RESULTS

While our findings showed that SOD levels were significantly different among the control and experimental groups and within the experimental groups, no statistical difference was found in terms of NO levels among the groups (Table 1). While the glomerular and tubular injury was higher in the Hyperoxia group and the Hyperoxia + Tadalafil group than in the control group (p < 0.001), as a result of the rate of severe glomerular and tubular injury in the hyperoxia group, was 62.5% and 43.8% and in the group given tadalafil was 43.8% and 31.3%, respectively (Table 2).

CONCLUSIONS

Exposure to hyperoxia condition causes renal glomerular and tubular damage, and tadalafil does not show a protective effect on this damage according to this study's dose and exposure time.

Tadalafil increases the antitumor activity of 5-FU through inhibiting PRMT5-mediated glycolysis and cell proliferation in colorectal cancer

BACKGROUND

Protein arginine methyltransferase 5 (PRMT5) is upregulated in multiple tumors and plays a pivotal role in cancer cell proliferation. However, the role of PRMT5 in colorectal cancer remains poorly understood.

METHODS

We detected the expression level of PRMT5 and glycolytic enzymes using online databases and colorectal cancer cell lines by immunohistochemical staining, quantitative real-time polymerase chain reaction (qRT-PCR), and western blotting. And MTT and colony formation assays were conducted to investigate cell proliferation. Then, we evaluated ECAR and OCR levels using a biological energy analyzer to investigate the energy status of colorectal cancer, and the transcriptional regulation was detected by dual luciferase reporter assay and ChIP assay. Finally, the efficacy of combined treatment of tadalafil and 5-FU was verified.

RESULTS

PRMT5 was highly expressed in colorectal cancer tissues compared with their normal counterparts and correlated with poor prognosis in CRC patients. Then, we demonstrated that PRMT5 knockdown or loss of function attenuated the viability of CRC cells, while overexpression of PRMT5 promoted cell proliferation. Mechanistically, PRMT5 enhanced glycolysis through transcriptionally activating LDHA expression. In addition, the PRMT5 inhibitor, tadalafil, rendered CRC cells sensitive to antitumor agent 5-FU in vitro and in vivo.

CONCLUSIONS

Our data indicates that PRMT5 promoted colorectal cancer proliferation partially through activating glycolysis and may be a potential target for colorectal cancer therapy.

Tadalafil Nanoemulsion Mists for Treatment of Pediatric Pulmonary Hypertension via Nebulization

Oral tadalafil (TD) proved promising in treating pediatric pulmonary arterial hypertension (PAH). However, to ensure higher efficacy and reduce the systemic side effects, targeted delivery to the lungs through nebulization was proposed as an alternative approach. This poorly soluble drug was previously dissolved in nanoemulsions (NEs). However, the formulations could not resist aqueous dilution, which precluded its dilution with saline for nebulization. Thus, the current study aimed to modify the previous systems into dilutable TD-NEs and assess their suitability for a pulmonary application. In this regard, screening of various excipients was conducted to optimize the former systems; different formulations were selected and characterized in terms of physicochemical properties, nebulization performance, stability following sterilization, and biocompatibility. Results showed that the optimal system comprised of Capmul-MCM-EP:Labrafac-lipophile (1:1) (w/w) as oil, Labrasol:Poloxamer-407 (2:1) (w/w) as surfactant mixture (S_mix) and water. The optimum formulation P2_TD resisted aqueous dilution, exhibited reasonable drug loading (2.45 mg/mL) and globule size (25.04 nm), acceptable pH and viscosity for pulmonary administration, and could be aerosolized using a jet nebulizer. Moreover, P2_TD demonstrated stability following sterilization and a favorable safety profile confirmed by both in-vitro and in-vivo toxicity studies. These favorable findings make P2_TD promising for the treatment of pediatric PAH.

Central Serous Chorioretinopathy Associated with Tadalafil

We report a case of central serous chorioretinopathy (CSCR) associated with tadalafil, a phosphodiesterase 5 inhibitor medication. In this report, we describe a case of a 59-year-old male who presented with blurred vision in the right eye. On examination, he was noted to have serous macular, pigment epithelial detachments, and increased choroidal thickness. The diagnosis of CSCR was made, and the patient was asked to stop the offending agent. Three months after stopping tadalafil, the patient's visual symptoms and subretinal fluid resolved. In conclusion, prescribing physicians should be aware of tadalafil's ability to decrease vision and cause CSCR. The addition of CSCR to the list of tadalafil's side effects should also be considered.

A Single-dose, Placebo-controlled Clinical Trial

OBJECTIVE

Obesity, a major health issue worldwide, is associated with increased cardiovascular risk, endothelial dysfunction, and arterial stiffness. Tadalafil has been demonstrated to improve vascular parameters.

AIM

To evaluate the effect of a single 20 mg dose of tadalafil on flow-mediated dilation and hemodynamic and arterial stiffness markers.

METHODS

A randomized, double-blind, placebo-controlled study was conducted on 80 participants (41 assigned to placebo and 39 to tadalafil) with grade 1 obesity, to evaluate the acute effect of a single dose of 20 mg of tadalafil on flow-mediated dilation and hemodynamic and arterial stiffness markers.

RESULTS

Tadalafil did not modify flow-mediated dilation. However, it significantly lowered systolic blood pressure (SBP) (130.6±17.1 vs. 125.0±12.7 mmHg, p=0.011), diastolic blood pressure (82.7±18.2 vs. 76.5±11.8 mmHg, p≤0.001), central systolic blood pressure (116.33±19.16 vs. 109.90±15.05 mmHg, p=0.001), the augmentation index (69.1±17.1 vs. 65.7±14.4, p=0.012), and brachial-ankle pulse wave velocity (1229.7±218.4 vs. 1164.0±181.7, p=0.001).

CONCLUSION

A single dose of tadalafil did not modify flow-mediated dilation in patients with grade 1 obesity but improved blood pressure and brachial-ankle pulse wave velocity.

Efficacy and safety of dutasteride with tadalafil add-on therapy in patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia

OBJECTIVE

To evaluate the efficacy and safety of add-on therapy with the phosphodiesterase type 5 inhibitor tadalafil in Japanese men with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) treated with dutasteride.

RESULTS

Twenty-four patients were enrolled. The participants had a median age of 71.0 (64.8-73.0) years and a median prostate volume of 37.3 (29.7-41.8) mL as measured using transabdominal sonography. The efficacy indicators, such as International Prostate Symptom Score (IPSS), quality of life (QOL) score, night-time urinary frequency, and night-time maximum voided volume, improved significantly at 4 weeks, and the effects lasted until 24 weeks (IPSS: 9.5 vs. 17.0, QOL: 2.0 vs. 4.0, nocturia: 2.0 vs. 2.0, night-time maximum voided volume: 290.0 vs. 240.0 mL). Overactive bladder symptom score (OABSS) and sexual health inventory for men (SHIM) significantly improved at 12 weeks, and the effects lasted until 24 weeks (OABSS: 3.0 vs. 5.0, SHIM: 11.0 vs. 7.5). However, maximum urine flow and residual urine volume showed no improvement at any point. Adverse events occurred in two cases. Taken together, add-on therapy with tadalafil was effective for patients with LUTS/BPH resistant to dutasteride monotherapy. In addition, this therapy was not associated with severe adverse events.

Efficacy of tadalafil on improvement of men with erectile dysfunction caused by COVID-19: A randomized placebo-controlled trial

Objective

According to the high prevalence of coronavirus disease (COVID-19) and the subsequent risk of men's sexual health, we decided to investigate the efficacy of tadalafil on improvement of men with erectile dysfunction caused by COVID-19.

Methods

In this study, 70 outpatients who were recovered from COVID-19 without acute respiratory distress syndrome with negative polymerase chain reaction test and a complaint of erectile dysfunction were divided into two groups: 35 patients who received tadalafil 5 mg daily and 35 who received placebo. For each patient, basic assessment of sexual function was performed using the 5-item version of the International Index of Erectile Function (IIEF) questionnaire. Then, treatment was started from two months after complete recovery of COVID-19 with negative polymerase chain reaction test for 3 months. At the end of the treatments, the patients were re-evaluated for sexual function using the complete version of IIEF questionnaire. Finally, the results before and after treatment in the intervention group were compared with those of the control group.

Results

Treatment with both tadalafil and placebo improved the patients' sexual function criteria compared to the baseline. However, this improvement was significantly higher in the intervention group with tadalafil than the control group with placebo (p<0.05).

Conclusions

Daily administration of tadalafil 5 mg seems to be effective and safe for improvement of erectile dysfunction caused by COVID-19.

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.

Effects of furosemide and tadalafil in both conventional and nanoforms against adenine-induced chronic renal failure in rats

BACKGROUND

Chronic renal failure (CRF) is a progressive loss of renal function that lead to reduced sodium filtration and inappropriate suppression of tubular reabsorption that ultimately leads to volume expansion. The aim of this study was to study the efficacy of furosemide and tadalafil nanoforms compared to conventional forms against adenine-induced CRF rat-model.

METHODS

Addition of 0.75% adenine to the diet of rats for 4 weeks gained general acceptance as a model to study kidney damage as this intervention mimicked most of the structural and functional changes seen in human chronic kidney disease Urine analysis, histopathological changes and immunohistochemical expression of caspase-3 and interleukin-1 beta (IL-1β) in renal tissues were performed.

RESULTS

Our results showed that the combination of tadalafil and furosemide using conventional and nanoparticle formulations had better renoprotective effect than individual drugs. This was demonstrated by improvement of urinary, serum and renal tissue markers as indicative of organ damage. This was also reflected on the reduction of tubular expression of kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL). Immunohistochemical studies showed that the deteriorated renal cellular changes indicated by increased expression of caspase-3 and IL-1β were greatly improved by the combined treatment particularly with the nanoforms.

CONCLUSIONS

The nanoforms of both furosemide and tadalafil had greater renopreventive effects compared with conventional forms against adenine-induced CRF in rats.

Tadalafil monotherapy in management of chronic prostatitis/chronic pelvic pain syndrome: a randomized double-blind placebo controlled clinical trial

Purpose

In this placebo-controlled trial, we aimed to evaluate the clinical results of using PDE-5 inhibitor, tadalafil 5 mg OD, for management of CP/CPPS.

Patients and methods

140 patients ≤ 45 years old with moderate/severe CP/CPPS associated with ED (IIEF-5 < 22) were randomly divided and received either tadalafil 5 mg OD (tadalafil-group) or placebo (control-group) for 6 weeks. Post-treatment CPSI scores were compared to baseline and to placebo. Clinically significant responders (≥ 25% reduction from baseline score) were calculated. Tadalafil-induced changes in IIE-5 were evaluated in correlation to that of CPSI scores.

Results

By the 6th week, 59 and 56 patients were available in both groups respectively. Compared to baseline, tadalafil-group patients showed significant improvement in total, pain, urinary and Qol domains of CPSI (19.1 ± 5.26, 10.42 ± 3.55, 4.2 ± 1.72 and 4.47 ± 1.64 vs. 24.21 ± 5.05, 12.14 ± 3.57, 6.08 ± 1.53 and 6.22 ± 1.76), p < 0.5. When compared to placebo, all 6th week CPSI domains scores, except for pain, were significantly better in tadalafil-group (p < 0.05). Post-treatment pain score didn't significantly differ between both groups (10.42 ± 3.55, vs. 11.71 ± 3.9, p > 0.05). Clinically significant responders were 30 patients (50.8%) in tadalafil-group vs. 3 patients (5.4%) in control. Tadalafil-induced changes in IIEF-5 score had weak but significant correlation to Qol domain (r = − 0.28, p < 0.05).

Conclusion

Tadalafil 5 mg OD can significantly improve all CPSI domains as compared to baseline. Post-treatment CPSI scores, except for pain, were better than placebo. About 50.8% of patients can develop ≥ 25% reduction in their total CPSI scores after treatment. Apart from Qol domain, these changes are not significantly correlated to tadalafil-induced IIEF-5 scores changes.

Prospective comparison of tadalafil 5 mg alone, silodosin 8 mg alone, and the combination of both in treatment of lower urinary tract symptoms related to benign prostatic hyperplasia

Background

Men with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH), will have deterioration in the quality of life. Likewise, BPH can be complicated by damage to bladder function, bladder stones formation, hematuria, and impaired kidney function. The goal of treatment is to avoid all those effects caused by BPH.

Objective

To evaluate the efficacy of tadalafil alone, silodosin alone, and the combination of both in the treatment of LUTS associated with BPH.

Patients and methods

Patients in our department with BPH who had LUTS were assigned randomly to three groups: A (101 patients) received tadalafil, 5 mg; B (102 patients) received silodosin, 8 mg; and group C (105 patients) received the combination of tadalafil, 5 mg, and silodosin, 8 mg. For all participants, we asses changes in the maximum urinary flow rate (Qmax), International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF) score, Post-voiding urine (PVR) and all results were recorded and analyzed with the (SPSS) and Microsoft Excel 2010.

Results

Qmax, IPSS, PVR and IIEF score improved significantly more with the combination of tadalafil and silodosin than with either drug alone (p < 0.001). Three months after treatment, the mean Qmax values were 14.4 ml/sec in group A, 15.2 ml/sec in group B, and 15.8 ml/sec in group C; and the mean IPSSs were 17.6 in group A, 16.7 in group B, and 15.6 in group C (p < 0.001).

Conclusion

Tadalafil and silodosin are effective treatment options in men with BPH who have LUTS, but the combination of both is more effective and feasible in treating LUTS of BPH.

Role of ADMA/DDAH-1 and iNOS/eNOS signaling in the gastroprotective effect of tadalafil against indomethacin-induced gastric injury

Non-steroidal anti-inflammatory drugs (NSAIDs)-induced gastric ulcers represent a significant clinical concern and adversely affect the quality of life. Inducible nitric oxide synthase/endothelial nitric oxide synthase (iNOS/eNOS) and asymmetric dimethylarginine/ dimethylarginine dimethylaminohydrolase-1 (ADMA/DDAH-1) signaling are key players in gastric ulcer pathogenesis. This work was planned to explore the role of iNOS/eNOS and ADMA/DDAH-1 signaling in rats with indomethacin-induced gastric ulcer, as potential pathways for the gastro-protective effect of tadalafil. Split into 5 separate groups, rats were assigned to control, tadalafil (10 mg/kg, p.o), indomethacin (single oral dose of 60 mg/kg), indomethacin + pantoprazole (40 mg/kg, p.o), and indomethacin + tadalafil (10 mg/kg, p.o). The results indicated that pretreatment with tadalafil significantly reduced ulcer index (UI), increased preventive index (PI), and counteracted indomethacin-induced histopathological aberrations. Tadalafil significantly reduced the gastric content of NO while it significantly elevated that of GSH and enhanced SOD activity. It significantly reduced the gastric expression of TNF-α and ADMA while it significantly elevated that of COX-2, PGE-2, and DDAH-1. Western blot analysis revealed that pretreatment with tadalafil significantly reduced iNOS protein expression while it significantly elevated that of eNOS. Collectively, these data suggest that tadalafil exerts potential protective effect against indomethacin-induced ulcer through suppression of inflammation, attenuation of oxidative stress, and boosting of antioxidants. Moreover, tadalafil protective effects are mediated via upregulation of PGE-2 with modulating the signaling pathways of ADMA/DDAH-1, and iNOS/eNOS. As a result, the current evidence corroborates the use of tadalafil in controlling gastric ulcers and preventing NSAID gastric side effects.

Application of hydrophilic polymers for the preparation of tadalafil solid dispersions: micromeritics properties, release and erectile dysfunction studies in male rats

The objective of the present study was to improve the dissolution rate and aphrodisiac activity of tadalafil by using hydrophilic polymers. Solid dispersions were prepared by solvent evaporation-Rota evaporator using Koliphore 188, Kollidon^® VA64, and Kollidon^® 30 polymers in a 1:1 ratio. Prepared tadalafil-solid dispersions (SDs) evaluated for yield, drug content, micromeritics properties, physicochemical characterizations, and aphrodisiac activity assessment. The optimized SDs TK188 showed size (2.175 ± 0.24 µm), percentage of content (98.89 ± 1.23%), yield (87.27 ± 3.13%), bulk density (0.496 ± 0.005 g/cm3), true density (0.646 ± 0.003 g/cm3), Carr's index (23.25 ± 0.81), Hausner ratio (1.303 ± 0.003) and angle of repose (<25°). FTIR spectrums revealed tadalafil doesn't chemically interact with used polymers. XRD and DSC analysis represents TK188 SDs were in the amorphous state. Drug release was 97.17 ± 2.43% for TK188, whereas it was 32.76 ± 2.65% for pure drug at the end of 2 h with 2.96-fold increase in dissolution and followed release kinetics of Korsmeyer Peppa's model. MDT and DE were noted to be 17.48 minutes and 84.53%, respectively. Furthermore, TK188 SDs showed relative improvement in the sexual behavior of the male rats. Thus the developed SDs TK188 could be potential tadalafil carriers for the treatment of erectile dysfunction.

Effect of low-dose tadalafil once daily on glycemic control in patients with type 2 diabetes and erectile dysfunction: a randomized, double-blind, placebo-controlled pilot study

BACKGROUND

Phosphodiesterase type 5 inhibitors restore nitric oxide signaling, that plays a significant role in erectile function, and appears to counteract insulin resistance in animal and human models. This study was aimed to evaluate the glycemic and metabolic effects of low-dose tadalafil once daily in patients with type 2 diabetes and erectile dysfunction.

METHODS

A 6-month, randomized, double-blind, placebo-controlled pilot trial was conducted. Eligible patients were randomly assigned in a ratio of 2:1 to the tadalafil 5 mg and placebo groups; all patients received either tadalafil or placebo once a day. The primary efficacy endpoint was the absolute change in glycated hemoglobin (HbA1c) levels during the 6-month study period. The secondary efficacy endpoints included metabolic parameters and erectile function.

RESULTS

Of the 68 patients who completed this study, 45 and 23 patients were allocated to the tadalafil and placebo groups, respectively. The mean HbA1c level was significantly different between the groups over the 6-month study period (P = 0.021). After 6 months of treatment, the HbA1c decrement in the tadalafil group was greater than that in the placebo group (- 0.14 ± 0.53% vs. 0.20 ± 0.69%, P = 0.030). The International Index of Erectile Function-5 scores improvement was significantly greater in the tadalafil group than in the placebo group at 6 months (P = 0.003).

CONCLUSION

This prospective pilot study showed that low-dose tadalafil administered once a day was effective in improving glycemic control and erectile function in patients with type 2 diabetes and erectile dysfunction. Trial registration KCT0005666.

The synergistic effects of testosterone and phophodiesterase-5 inhibitor combination on oxidative stress markers, matrix metalloproteinases and oxidative DNA damage: A randomized controlled experimental study

PURPOSE

To investigate the effects of combined tadalafil and testosterone usage on oxidative stress, DNA damage and MMPs in testosterone deficiency.

METHODS

Fifty rats were randomly divided into 5 groups (group-1: sham group-placebo, group-2: bilateral orchiectomy (ORX), group-3: bilateral ORX+tadalafil, group-4: bilateral ORX+testosterone, group-5: bilateral ORX+tadalafil+testosterone). Group-3 received tadalafil (5mg/kg/day, oral). Group-4 was administered testosterone undecanoate (100mg/kg i.m., single dose). Group-5 was administered a combination of tadalafil and testosterone undecanoate. All groups were compared with regard to serum nicotinamide adenine dinucleotide phosphate oxidase-4 (NOX-4), total thiol, matrix metalloproteinase-2 (MMP-2), MMP-3 and MMP-9, tissue inhibitor of metalloproteinases-1 (TIMP-1) and TIMP-2 and 8-hydroxy-2-deoxy guanosine (8-OHdG) levels.

RESULTS

Total thiol levels of group-2 were significantly lower than the other groups and thiol levels were higher in group-1 and group-5 than in the other groups. NOX4, MMP2 and 9 levels in group-2 were higher than in the other groups. MMP-9 levels in group-5 were lower than in groups 3 and 4 (p=.001). The level of 8-OHdG in groups 2 and 3 was higher than in the other groups (p=.001). In correlation analysis, 8-OHdG, MMP2, and 9 levels were negatively correlated with total thiol, whereas NOX4 and 8-OHdG levels were positively correlated with MMPs values.

CONCLUSIONS

The combination of testosterone with PDE-5 inhibitor suppresses MMP-9 levels and increases total thiol levels better than testosterone alone and tadalafil alone. Therefore, testosterone can be considered for use with PDE-5 inhibitor from the initial stage in case of testosterone deficiency.

Dutasteride add-on treatment to tadalafil for patients with benign prostatic enlargement is similarly effective as dutasteride add-on treatment to alpha blocker: a propensity-score matching analysis

PURPOSE

To investigate the efficacy of dutasteride add-on treatment to tadalafil in patients with lower urinary tract symptoms (LUTS) suggestive of benign prostatic enlargement (BPE).

METHODS

A prospective study was conducted in patients with BPE who had not been satisfied with tadalafil monotherapy for more than 3 months. Inclusion criteria were prostate volume (PV) ≥ 30 ml and IPSS ≥ 8 or QOL index ≥ 3 under administration of tadalafil without anticholinergic agent. Before and 24 weeks after dutasteride add-on treatment to tadalafil, we assessed IPSS, overactive bladder symptom score (OABSS), serum PSA and testosterone, and uroflowmetry (UFM) to compare these parameters before and after dutasteride add-on treatment. Using a propensity-score matching analysis, the efficacy of dutasteride add-on treatment to tadalafil was compared with the previous study of dutasteride add-on treatment to alpha blocker.

RESULTS

Of 52 patients who were enrolled in this study, 48 patients completed the study (mean age: 72 ± 5 years old). Dutasteride add-on treatment to tadalafil significantly improved IPSS (from 16.4 ± 5.2 to 13.3 ± 6.4) and IPSS-QOL (from 4.0 ± 1.2 to 3.3 ± 1.1), and reduced PV from 55 ± 26 to 39 ± 22 ml. Propensity-score matching identified 42 matched pairs of patients. The improvement rate of IPSS and reduction rate of PV were similar between patients treated with dutasteride add-on treatment to tadalafil and dutasteride add-on treatment to alpha blocker. The logistic regression analysis showed that PV at baseline and reduction rate of PV after treatment were associated with the effective symptomatic outcome.

CONCLUSIONS

The dutasteride add-on is a reasonable treatment option for male patients with LUTS who are not satisfied with tadalafil monotherapy.

Bilateral neurosensory retinal detachment secondary to tadalafil treatment

A 53-year-old male with no systemic disorders, other than controlled arterial hypertension, presented with asymptomatic, bilateral neurosensory retinal detachment (NRD) detected during a routine revision. The patient reported the use of tadalafil (a phosphodiesterase-5 inhibitor [PDE5I]) for erectile dysfunction. Following suspension of the drug, subretinal fluid reabsorption was confirmed, with the persistence of chronic alterations in the optical coherence tomography (OCT) and the visual field. PDE5Is have ocular side effects, including exudative retinal detachment. Although no direct causal relationship has been confirmed, PDE5 inhibition at chorioretinal level produces vasodilatation, increased choroid hydrostatic pressure, and exudation into the subretinal space. In cases of NRD, a thorough assessment of the drug treatment history is crucial. Patients who use PDE5I drugs should be alerted to their potential ocular side effects.

Phosphodiesterase 5 inhibitor suppresses prostate weight increase in type 2 diabetic rats

AIMS

Hyperinsulinemia is an important causative factor of prostate enlargement in type 2 diabetes (T2D), however, clinically prostate weight increases during hypoinsulinemic condition. To investigate the pathogenesis of prostate enlargement and effects of phosphodiesterase 5 inhibitor (PDE5i), male Otsuka Long-Evans Tokushima Fatty (OLETF) and Long-Evans Tokushima Otsuka (LETO) rats were used as T2D and control, respectively.

MATERIALS AND METHODS

OLETF and LETO rats were treated with oral tadalafil (100 μg/kg/day) or vehicle for 12 wks from at the age of 36 wks.

KEY FINDINGS

Prostate weight of OLETF rats was significantly higher than that of LETO at 36 wks, and increased at 48 wks. In OLETF rats, prostate blood flow was significantly lower at 48 wks versus 36 wks. Twelve-week-tadalafil treatment increased prostate blood flow and suppressed prostate weight increase in both strains. This change was inversely correlated with changes in prostate expressions of hypoxia-inducible factor-1 alpha (HIF-1α) and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Increases with age were observed in mRNA and/or protein levels of cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha (TNF-α) and cell growth factors insulin-like growth factor-1 (IGF-1), basic fibroblast growth factor (bFGF), and transforming growth factor-beta (TGF-β); especially IL-6, TNF-α, IGF-1, bFGF and TGF-β increased with T2D. Tadalafil suppressed these cytokines and growth factors.

SIGNIFICANCE

These data suggest chronic ischemia caused by T2D leads to oxidative stress, resulting in prostate enlargement through upregulation of several cytokines and growth factors. Treatment with PDE5i improves prostate ischemia and might prevent enlargement via suppression of cytokines and growth factors in T2D.

Maternal blood concentration of tadalafil in pregnancy: Comparison of pregnant and non-pregnant women

OBJECTIVE

In this study, the drug kinetics of tadalafil were compared between pregnant and non-pregnant women to determine the ideal dosage to promote uterine blood flow.

MATERIALS AND METHODS

We recruited five pregnant and five non-pregnant women, all of which were administered tadalafil (20 mg/day). The blood concentration of tadalafil was measured 1, 2, 4, 6, 8, and 24 h after administration. We investigated the side effects within 4 days of tadalafil administration and compared the cumulative frequency between the two groups.

RESULTS

The mean area under the concentration-time curve and maximum blood concentration of tadalafil were not different between the pregnant and non-pregnant groups. Time to maximum blood concentration was delayed by 1 min on average in the pregnant group compared with the non-pregnant group. The cumulative frequency of side effects was significantly lower in the pregnant group than in the non-pregnant group (P = 0.026). No side effects were observed in either group after the fifth day of the tadalafil administration.

CONCLUSION

Although there was no difference in maximum blood concentration between non-pregnant and pregnant women, the rate of side effects was lower in pregnant women than in non-pregnant women. Therefore, pregnant women may tolerate tadalafil better.

Phosphodiesterase (PDE) 5 inhibitors sildenafil, tadalafil and vardenafil impact cAMP-specific PDE8 isoforms-linked second messengers and steroid production in a mouse Leydig tumor cell line

Type 5 phosphodiesterase (PDE5) blockade by inhibitors (PDE5i) results in intracellular cyclic guanosine monophosphate (cGMP) increase and smooth muscle relaxation and are used for the treatment of men erectile dysfunction. Although they have high specificity for PDE5, these inhibitors are suspected to cross-interact also with cyclic adenosine monophosphate (cAMP)-specific PDEs, inducing the intracellular accumulation of this cyclic nucleotide and related testosterone increase, positively impacting male reproductive parameters. However, the link between the use of PDE5i and the activation of cAMP-mediated steroidogenesis is still unclear. We have investigated whether three PDE5i, sildenafil, tadalafil and vardenafil, cross-interacts with the high affinity cAMP-specific enzymes type 8A and 8B PDEs (PDE8A and PDE8B), in live, transfected mouse Leydig tumor (mLTC1) and human embryonic kidney (HEK293) cell lines in vitro. The PDE5i-induced production of cAMP-dependent testosterone and its precursor progesterone was evaluated as well. We have developed PDE8A/B biosensors and modified cyclic nucleotides confirming enzyme binding to cAMP, but not to cGMP, in our cell models. cAMP binding to PDE8A/B was displaced upon cell treatment with PDE5i, revealing that sildenafil, tadalafil and vardenafil have similar effectiveness in live cells, in vitro. The cross-interaction between PDE5i and PDE8A/B supports the gonadotropin-enhanced intracellular cAMP increase, occurring together with cGMP increase, as well as steroid synthesis. Indeed, we found that Leydig cell treatment by PDE5i increases progesterone and testosterone production triggered by gonadotropins. We demonstrated that PDE5i may interact with the cAMP-specific PDE8A and PDE8B, possibly inducing intracellular cAMP and sex steroid hormone increase. These findings support clinical data suggesting that PDE5i might increase testosterone levels in men.

Tadalafil treatment improves cardiac, renal and lower urinary tract dysfunctions in rats with heart failure

Tadalafil, a phosphodiesterase-5 (PDE5) inhibitor, shown to exert a protection to heart failure (HF) associated damage or lower urinary tract symptoms (LUTS). Thus, we investigated the contribution of tadalafil chronic treatment in the alterations of LUTS in HF rats. Male rats were subjected to aortocaval fistula model for HF induction. Echocardiography, cystometric, renal function and redox cell balance, as well as concentration-response curves to carbachol, KCl, ATP and frequency-response curves to electrical field stimulation (EFS) were evaluated in Sham, HF, Tadalafil and HF-Tadalafil (12 weeks endpoint) groups. HF group to present increased in left-ventricle (LV) mass and in LV end-diastolic- and LV end-systolic volume, with a decreased ejection fraction. Tadalafil treatment was able to decrease in hypertrophy and improve the LV function restoring cardiac function. For micturition function (in vivo), HF animals shown an increase in basal pressure, threshold pressure, no-voiding contractions and decreased bladder capacity, being that the tadalafil treatment restored the cystometric parameters. Contractile mechanism response (in vitro) to carbachol, KCl, ATP and EFS in the detrusor muscles (DM) were increased in the HF group, when compared to Sham group. However, tadalafil treatment restored the DM hypercontractility in the HF animals. Moreover, renal function as well as the oxidative mechanism was impaired in the HF animals, and the tadalafil treatment improved all renal and oxidative parameters in HF group. Our data shown that tadalafil has potential as multi-therapeutic drug and may be used as a pharmacological strategy for the treatment of cardiovascular, renal and urinary dysfunctions associated with HF.