Cardiovascular effects of the 3 phosphodiesterase-5 inhibitors approved for the treatment of erectile dysfunction

Design, synthesis, and biological evaluation of some new 2-phenyl-3,6-pyridazinedione derivatives as PDE-5 inhibitors

Various 2-phenyl-3,6-pyridazinedione derivatives 4a-j, 5a-c, 6a,b, 7a-c, 8, 9, 10a-d, and 11a-d, were effectivelysynthesized, and tested for their potential inhibition of phosphodiesterase enzyme at 10 µM. Then fourteen compounds exhibiting the highest inhibition 4b, 4d, 4e, 4g, 4h, 4i, 5a, 6a,b, 7c, 10a,b, 11a, and 11d were selected for screening their PDE-5 inhibition, where compounds 4b,g,h, and 11a revealed promising PDE-5 inhibition having IC50 values = 25, 53, 22, and 42 nM, respectively in comparison with Sildenafil (IC50 = 16 nM). Additionally, these four most active compounds were safe to normal fibroblast cell line WI-38. Moreover, 4f, 4h, 4j, 10d, and 11d had almost the same anti-proliferative effect against the aortic cell line as Sildenafil. Furthermore, molecular docking illustrated that the binding of the target compounds with the key amino acids in the binding site of PDE-5 (PDB 2H42) was like to that of the cocrystallized ligand Sildenafil. Additionally, molecular dynamics simulation for the most active compound 4h revealed high stability of the 4h -PDE5 complex explaining its promising activity as a PDE-5 inhibitor. Therefore, the 2-phenyl-3,6-pyridazinedione scaffold can be considered an important core for designing more promising PDE-5 inhibitors.

The Effect of Udenafil on Heart Rate and Blood Pressure in Adolescents With the Fontan Circulation

The Fontan Udenafil Exercise Longitudinal (FUEL) trial showed that treatment with udenafil was associated with improved exercise performance at the ventilatory anaerobic threshold in children with Fontan physiology. However, it is not known how the initiation of phosphodiesterase 5 inhibitor therapy affects heart rate and blood pressure in this population. These data may help inform patient selection and monitoring after the initiation of udenafil therapy. The purpose of this study is to evaluate the effects of udenafil on vital signs in the cohort of patients enrolled in the FUEL trial. This international, multicenter, randomized, double-blind, placebo-controlled trial of udenafil included adolescents with single ventricle congenital heart disease who had undergone Fontan palliation. Changes in vital signs (heart rate [HR], systolic [SBP] and diastolic blood pressure [DBP]) were compared both to subject baseline and between the treatment and the placebo groups. Additional exploratory analyses were performed to evaluate changes in vital signs for prespecified subpopulations believed to be most sensitive to udenafil initiation. Baseline characteristics were similar between the treatment and placebo cohorts (n = 200 for each). The groups demonstrated a decrease in HR, SBP, and DBP 2 hours after drug/placebo administration, except SBP in the placebo group. There was an increase in SBP from baseline to after 6-min walk test in the treatment and placebo groups, and the treatment group showed an increase in HR (87.4 ± 15.0 to 93.1 ± 19.4 beats/min, p <0.01) after exercise. When comparing changes from baseline to the 26-week study visit, small decreases in both SBP (-1.9 ± 12.3 mm Hg, p = 0.03) and DBP (-3.0 ± 9.6 mm Hg, p <0.01) were seen in the treatment group. There were no clinically significant differences between treatment and placebo group in change in HR or blood pressure in the youngest age quartile, lightest weight quartile, or those on afterload-reducing agents. In conclusion, initiation of treatment with udenafil in patients with Fontan circulation was not associated with clinically significant changes in vital signs, implying that for patients similar to those enrolled in the FUEL trial, udenafil can be started without the requirement for additional monitoring after initial administration.

A drug target for erectile dysfunction to help improve fertility, sexual activity, and wellbeing: mendelian randomisation study

OBJECTIVE

To investigate the association of genetically proxied (using a surrogate biomarker) inhibition of phosphodiesterase 5 (PDE5), an established drug target for erectile dysfunction, with fertility, sexual behaviour, and subjective wellbeing.

DESIGN

Two sample cis-mendelian randomisation study.

SETTING

Summary data on genetic associations obtained from the International Consortium for Blood Pressure and UK Biobank.

PARTICIPANTS

Individuals of European ancestry from the International Consortium for Blood Pressure (n=757 601) for estimating PDE5 inhibition (using the surrogate biomarker of diastolic blood pressure reduction), and UK Biobank (n=211 840) for estimating the fertility, sexual behaviour, and subjective wellbeing outcomes in male participants.

INTERVENTION

Genetically proxied PDE5 inhibition.

MAIN OUTCOME MEASURES

Number of children fathered, number of sexual partners, probability of never having had sexual intercourse, and subjective wellbeing.

RESULTS

Genetically proxied PDE5 inhibition was associated with male participants having 0.28 (95% confidence interval 0.16 to 0.39) more children (false discovery rate corrected P<0.001). This association was not identified in female participants. No evidence was found of an association between genetically proxied PDE5 inhibition and number of sexual partners, probability of never having had sexual intercourse, or self-reported wellbeing in male participants.

CONCLUSIONS

The findings of this study provide genetic support for PDE5 inhibition potentially increasing the number of children fathered by male individuals. Absence of this association in female participants supports increased propensity for sustained and robust penile erections as a potential underlying mechanism. Further studies are required to confirm this, however, and these findings should not promote indiscriminate use of PDE5 inhibitors, which can also have harmful adverse effects.

Targeting CaMKK2 Inhibits Actin Cytoskeletal Assembly to Suppress Cancer Metastasis

Triple-negative breast cancers (TNBC) tend to become invasive and metastatic at early stages in their development. Despite some treatment successes in early-stage localized TNBC, the rate of distant recurrence remains high, and long-term survival outcomes remain poor. In a search for new therapeutic targets for this disease, we observed that elevated expression of the serine/threonine kinase calcium/calmodulin (CaM)-dependent protein kinase kinase 2 (CaMKK2) is highly correlated with tumor invasiveness. In validation studies, genetic disruption of CaMKK2 expression or inhibition of its activity with small molecule inhibitors disrupted spontaneous metastatic outgrowth from primary tumors in murine xenograft models of TNBC. High-grade serous ovarian cancer (HGSOC), a high-risk, poor prognosis ovarian cancer subtype, shares many features with TNBC, and CaMKK2 inhibition effectively blocked metastatic progression in a validated xenograft model of this disease. Mechanistically, CaMKK2 increased the expression of the phosphodiesterase PDE1A, which hydrolyzed cyclic guanosine monophosphate (cGMP) to decrease the cGMP-dependent activity of protein kinase G1 (PKG1). Inhibition of PKG1 resulted in decreased phosphorylation of vasodilator-stimulated phosphoprotein (VASP), which in its hypophosphorylated state binds to and regulates F-actin assembly to facilitate cell movement. Together, these findings establish a targetable CaMKK2-PDE1A-PKG1-VASP signaling pathway that controls cancer cell motility and metastasis by impacting the actin cytoskeleton. Furthermore, it identifies CaMKK2 as a potential therapeutic target that can be exploited to restrict tumor invasiveness in patients diagnosed with early-stage TNBC or localized HGSOC.

SIGNIFICANCE

CaMKK2 regulates actin cytoskeletal dynamics to promote tumor invasiveness and can be inhibited to suppress metastasis of breast and ovarian cancer, indicating CaMKK2 inhibition as a therapeutic strategy to arrest disease progression.

Ca 2+ /Calmodulin Dependent Protein Kinase Kinase-2 (CaMKK2) promotes Protein Kinase G (PKG)-dependent actin cytoskeletal assembly to increase tumor metastasis

Triple-negative breast cancers (TNBCs) tend to become highly invasive early during cancer development. Despite some successes in the initial treatment of patients diagnosed with early-stage localized TNBC, the rate of metastatic recurrence remains high with poor long-term survival outcomes. Here we show that elevated expression of the serine/threonine-kinase, Calcium/Calmodulin (CaM)-dependent protein kinase kinase-2 (CaMKK2), is highly correlated with tumor invasiveness. We determined that genetic disruption of CaMKK2 expression, or inhibition of its activity, disrupted spontaneous metastatic outgrowth from primary tumors in murine xenograft models of TNBC. High-grade serous ovarian cancer (HGSOC), a high-risk, poor-prognosis ovarian cancer subtype, shares many genetic features with TNBC, and importantly, CaMKK2 inhibition effectively blocked metastatic progression in a validated xenograft model of this disease. Probing the mechanistic links between CaMKK2 and metastasis we defined the elements of a new signaling pathway that impacts actin cytoskeletal dynamics in a manner which increases cell migration/invasion and metastasis. Notably, CaMKK2 increases the expression of the phosphodiesterase PDE1A which decreases the cGMP-dependent activity of protein kinase G1 (PKG1). This inhibition of PKG1 results in decreased phosphorylation of Vasodilator-Stimulated Phosphoprotein (VASP), which in its hypophosphorylated state binds to and regulates F-actin assembly to facilitate contraction/cell movement. Together, these data establish a targetable CaMKK2-PDE1A-PKG1-VASP signaling pathway that controls cancer cell motility and metastasis. Further, it credentials CaMKK2 as a therapeutic target that can be exploited in the discovery of agents for use in the neoadjuvant/adjuvant setting to restrict tumor invasiveness in patients diagnosed with early-stage TNBC or localized HGSOC.

A Systematic Review and Meta-Analysis of the Efficacy and Safety of Tamsulosin Plus Tadalafil Compared With Tamsulosin Alone in Treating Males With Lower Urinary Tract Symptoms Secondary to Benign Prostrate Hyperplasia

Lower urinary tract symptoms (LUTS) secondary to benign prostrate hyperplasia (BPH) are common geriatric diseases, and its incidence rises with age. The treatment of BPH and LUTS is becoming a burden for health care. The meta-analysis was performed to evaluate the efficacy and safety of combination therapy (tamsulosin plus tadalafil) compared with tamsulosin alone in treatment of males with LUTS/BPH. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were utilized to conduct this study. There were several databases available for literature retrieval, including Medline, Embase, PubMed, Scopus, Web of Science databases, and Cochrane Controlled Trials Register. To improve the comprehensiveness of the search, related references were also searched. Finally, six randomized controlled trials including 441 patients were included. The combination therapy had significant improvements in total International Prostate Symptom Score (p < .0001), quality of life score (p = .003), maximum urine flow rate (p < .00001), and International Index of Erectile Function (p < .00001) compared with the tamsulosin monotherapy, but there was no obvious difference in postvoid residual volume (p = .06). In terms of safety, the combination group had comparable rates of discontinuation due to adverse events (p = .19) than the monotherapy group except for pain symptoms (p < .0001). The combination of tamsulosin and tadalafil provided a preferable therapeutic effect compared with the tamsulosin alone in treating males with BPH/LUTS, and both therapy regimens were well tolerated by the patients.

MANP Activation Of The cGMP Inhibits Aldosterone Via PDE2 And CYP11B2 In H295R Cells And In Mice

BACKGROUND

Aldosterone is a critical pathological driver for cardiac and renal diseases. We recently discovered that mutant atrial natriuretic peptide (MANP), a novel atrial natriuretic peptide (ANP) analog, possessed more potent aldosterone inhibitory action than ANP in vivo. MANP and natriuretic peptide (NP)-augmenting therapy sacubitril/valsartan are under investigations for human hypertension treatment. Understanding the elusive mechanism of aldosterone inhibition by NPs remains to be a priority. Conflicting results were reported on the roles of the pGC-A (particulate guanylyl cyclase A receptor) and NP clearance receptor in aldosterone inhibition. Furthermore, the function of PKG (protein kinase G) and PDEs (phosphodiesterases) on aldosterone regulation are not clear.

METHODS

In the present study, we investigated the molecular mechanism of aldosterone regulation in a human adrenocortical cell line H295R and in mice.

RESULTS

We first provided evidence to show that pGC-A, not NP clearance receptor, mediates aldosterone inhibition. Next, we confirmed that MANP inhibits aldosterone via PDE2 (phosphodiesterase 2) not PKG, with specific agonists, antagonists, siRNA silencing, and fluorescence resonance energy transfer experiments. Further, the inhibitory effect is mediated by a reduction of intracellular Ca2+ levels. We then illustrated that MANP directly reduces aldosterone synthase CYP11B2 (cytochrome p450 family 11 subfamily b member 2) expression via PDE2. Last, in PDE2 knockout mice, consistent with in vitro findings, embryonic adrenal CYP11B2 is markedly increased.

CONCLUSIONS

Our results innovatively explore and expand the NP/pGC-A/3',5', cyclic guanosine monophosphate (cGMP)/PDE2 pathway for aldosterone inhibition by MANP in vitro and in vivo. In addition, our data also support the development of MANP as a novel ANP analog drug for aldosterone excess treatment.

Effects of Erectile Dysfunction Drugs Use on T-cells and Immune Markers on Men Who Have Sex with Men

Objective

Examine prospective relationships between erectile dysfunction (ED) drugs EDand CD4 and CD8 T-cells, and immune markers among men who have sex with men (MSM).

Methods

Data from Multicenter AIDS Cohort Study, an observational prospective cohort study, with semi-annual follow-ups conducted in four U.S. centers from 1998 onwards was used. Marginal structural models using g-computation was fitted to estimate the mean differences for the effects of self-reported ED drug use on CD4 and CD8 T-cell outcomes and immune biomarkers.

Results

Total of 1,391 men with HIV (MWH) and 307 men without HIV (MWOH) was included. Baseline mean CD4 cell count among MWH and MWOH was 499.9 cells/μL and 966.7 cells/μL, respectively. At baseline, 41.8% of MWH were virally suppressed. ED drug users reported a mean of 44.4 months of exposure to ED drugs. ED drug use was associated with increased CD4 cell outcomes among MWH but not MWOH. Mean differences in CD4 cell counts after 1 year of ED drug use was 57.6 cells/μL and increased to 117.7 after 10 years among MWH. CD8 counts were higher in ED drug users among MWH over 10 years than non-users; no consistent differences were found among MWOH. ED drug use appeared to reduce immune marker levels, such as IL-6 and increase markers, such as IL-10. We observed similar effects of ED drug use on biomarker levels among MWOH.

Conclusion

Long-term use of ED drugs do not adversely affect immune function among MWH or MWOH. Future studies on the relationships between different types of ED drugs and effects on T-cell subtypes are warranted.

Retrospective Observational Real-World Outcome Study to Evaluate Safety Among Patients With Erectile Dysfunction (ED) With Co-Possession of Tadalafil and Anti-Hypertensive Medications (anti-HTN)

BACKGROUND

Erectile dysfunction (ED) is a common condition affecting male adults and may be associated with hypertension, diabetes, hyperlipidemia, and obesity. Phosphodiesterase type 5 (PDE5) inhibitors, such as tadalafil, are the first-line drug therapy for ED. Studies and the current prescribing information of these PDE5 inhibitors indicate they are mechanistic mild vasodilators and, as such, concomitant use of a PDE5 inhibitor with anti-hypertensive medication may lead to drops in blood pressure due to possible drug-drug interaction.

AIM

Evaluate risks of hypotensive/cardiovascular outcomes in a large cohort of patients with ED that have co-possession of prescriptions for tadalafil and hypertensive medications versus either medication/s alone.

METHODS

A cohort study conducted within an electronic health record database (Optum) representing hospitals across the US. Adult male patients prescribed tadalafil and/or anti-hypertensive medications from January 2012 to December 2017 were eligible. Possession periods were defined by the time patients likely had possession of medication, with propensity score-matched groups used for comparison.

OUTCOMES

Risk of hypotensive/cardiovascular outcomes were measured using diagnostic codes and NLP algorithms during possession periods of tadalafil + anti-hypertensive versus either medication/s alone.

RESULTS

In total there were 127,849 tadalafil + anti-hypertensive medication possession periods, 821,359 anti-hypertensive only medication possession periods, and 98,638 tadalafil only medication possession periods during the study; 126,120 were successfully matched. Adjusted-matched incidence rate ratios (IRRs) for the anti-hypertensive only possession periods compared with tadalafil + anti-hypertensive periods of diagnosed outcomes were all below 1. Two outcomes had a 95% confidence interval (CI) that did not include 1.0: ventricular arrhythmia (IRR 0.79; 95% CI 0.66, 0.94) and diagnosis of hypotension (IRR 0.79; 95% CI 0.71, 0.89).

CLINICAL IMPLICATIONS

Provides real world evidence that co-possession of tadalafil and anti-hypertensive medications does not increase risk of hypotensive/cardiovascular outcomes beyond that observed for patients in possession of anti-hypertensive medications only.

STRENGTHS AND LIMITATIONS

EHR data are valuable for the evaluation of real world outcomes, however, the data are retrospective and collected for clinical patient management rather than research. Prescription data represent the intent of the prescriber and not use by the patient. Residual bias cannot be ruled out, despite propensity score matching, due to unobserved patient characteristics and severity that are not fully reflected in the EHR database.

CONCLUSION

In the studied real world patients, this study did not demonstrate an increased risk of hypotensive or cardiovascular outcomes associated with co-possession of tadalafil and anti-hypertensive medications beyond that observed for patients in possession of anti-hypertensive medications only. Nunes AP, Seeger JD, Stewart A, et al., Retrospective Observational Real-World Outcome Study to Evaluate Safety Among Patients With Erectile Dysfunction (ED) With Co-Possession of Tadalafil and Anti-Hypertensive Medications (anti-HTN). J Sex Med 2022;19:74-82.

Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of Vardenafil and Its Application of Bioequivalence

A simple, rapid, and sensitive method of liquid chromatography-tandem mass spectrometry (LC/MS/MS) method was developed and validated for the determination of vardenafil in rabbit plasma. A simple protein precipitation method with ice-cold acetonitrile was used for plasma extraction. The mass transitions m/z 489⟶151 and m/z 390⟶169 were used to measure vardenafil and tadalafil (internal standard), respectively, with a total assay run time of 6 min. The limit of detection was 0.2 ng/mL. The assay was reproducible with intra-assay and interassay precision ranging 1.17%-9.17% and 1.31%-5.86%, respectively. There was also good intra-assay and interassay accuracy between 89.3%-105.3% and 94%-102% of the expected value, respectively. The linearity range was 0.5-60 ng/mL in rabbit plasma (r 2 ≥ 0.99). The measured AUC from 0 to 24 h (AUC0 - 24t ) for the test and reference formulations were 174.38 ± 95.91 and 176.45 ± 76.88, respectively. For the test, C max and T max were 75.36 ± 59.53 ng/mL and 1.42 ± 0.19 h, whereas, for the reference, these were 58.22 ± 36.11 ng/mL and 2.04 ± 0.33 h, respectively. The test formulation achieved a slightly lower AUC0 - 24t value (p > 0.05), higher C max values (p > 0.05), faster T max (p < 0.05), and almost equal bioavailability compared with the reference formulation.

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.

Stability assessment of tamsulosin and tadalafil co-formulated in capsules by two validated chromatographic methods

The advent of a new pharmaceutical formulation evokes the need for examining the chemical stability of their constituents and establishing proper stability-indicating methods. Herein, the stability of the newly co-formulated Tamsulosin and Tadalafil were examined under different stress conditions. The acidic degradation of Tamsulosin yielded its sulfonated derivative, while Tadalafil was susceptible to both acidic and basic degradation. Two stability-indicating chromatographic methods, namely; high-performance thin-layer chromatography and high-performance liquid chromatography, have been developed. Significant high-performance thin-layer chromatography-fractionation could be achieved by utilizing a stationary phase of silica gel 60 F₂₅₄ and a mobile phase composed of ethyl acetate/toluene/methanol/ammonia (4:2:4:0.6, by volumes) with densitometric recording at 280 nm over a concentration range of 0.5-25 μg/band for both drugs. The HPLC-separation could be reached on XBridge^® C₁₈ column isocraticaly by using a mobile phase having acetonitrile/phosphate buffer, pH 6.0 (45:55, v/v) pumped at a flow rate of 1.7 mL/min and applying diode array ultraviolet-detection at 210 nm over a linearity range of 3-70 μg/mL for each drug. Specificity of the two methods was additionally assured via peak purity assessment. Moreover, the methods were distinctly exploited for evaluating the drugs' stability in accelerated stability-studied samples of Tamplus^® capsules.

Meta-Analysis of Efficacy and Safety of Tadalafil Plus Tamsulosin Compared with Tadalafil Alone in Treating Men with Benign Prostatic Hyperplasia and Erectile Dysfunction

This meta-analysis was performed to evaluate the efficacy and safety of tadalafil plus tamsulosin compared with tadalafil alone in treating men with benign prostatic hyperplasia (BPH) and erectile dysfunction (ED) after 12 weeks’ treatment. Systematic review was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-analyses. MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched to collect randomized controlled trials. The references of related articles were also searched. Four articles including 621 patients were involved in the analysis. The study identified that combination-therapy had significant improvements in total international prostate symptom score (IPSS), quality of life (QoL) and maximum urine flow rate (Qmax) compared with monotherapy, and there were no obvious significance in respects of post-void residual volume, international index of erectile function and IPSS storage. The difference of total IPSS was mainly reflected in the change of IPSS voiding. For safety, combination-therapy had a higher incidence rate of any adverse events (AEs) and discontinuation due to AEs than monotherapy with the exception of pain. In conclusion, the combination of tadalafil and tamsulosin provided a better improvement of IPSS voiding, QoL and Qmax compared with tadalafil alone in treating men with BPH and ED, and the former therapy appeared to show a higher incidence of AEs.

Promising role of medicinal plants in the regulation and management of male erectile dysfunction

Male erectile dysfunction (ED) refers to incompetency to reaching and retaining adequate penile tumescence for sexual intercourse. Over 152 million men globally suffer from ED and by 2025, the number of affected individuals is anticipated to be around 322 million. Pharmacological and nonpharmacological therapies such as phosphodiesterase (PDE) inhibitors, alprostadil, penile prosthesis surgery, and hormonal replacement are available for management and recuperation of ED. Nevertheless, such therapies are reported to have adverse effects as well as life-threatening. Accordingly, diversity of medicinal plant species and bioactive active compounds are preferred as therapeutic options because they are natural, abundant, available, low-cost and cause fewer or no side effects. This current review will emphasise the aetiology, risk factors, mechanisms underlying the pathophysiology of ED, treatments of ED as well as their side effects. It also provides medicinal plants that are proven effective in vivo and in vitro for the mitigation and treatment of male ED. This knowledge could be used in the future in drug discovery for the development of more natural drugs with no side effects.

Tamsulosin and placebo vs tamsulosin and tadalafil in male lower urinary tract symptoms: a double-blinded, randomised controlled trial

OBJECTIVE

To compare the efficacy and safety of tamsulosin vs the combination of tamsulosin and tadalafil in male lower urinary tract symptoms (LUTS).

PATIENTS AND METHODS

This was a double-blinded, parallel-arm randomised controlled trial. Men aged >45 years with moderate LUTS and a maximum urinary flow rate (Q_max ) of 5-15 mL/s were included. One arm received 0.4 mg tamsulosin only (Group-A), while the second received 5 mg tadalafil with tamsulosin (Group-B). The primary outcome was the International Prostate Symptom Score (IPSS). Secondary outcomes were IPSS quality of life (QoL) score, five-item version of the International Index of Erectile Function (IIEF-5) score, Q_max , and post-void residual urine (PVR). Block randomisation was used. Placebo was used for blinding and allocation concealment. Intention-to-treat analysis was used for outcome measures.

RESULTS

Of the 183 men screened, 140 were randomised (71 in Group-A, 69 in Group-B); 116 (82.85%) (61 in Group-A, 55 in Group-B) completed the study. Baseline characteristics were comparable. The improvements in the IPSS, IPSS QoL score, IIEF score and Q_max were -1.69 (95% confidence interval [CI] -1.4 to -2.0), -0.70 (95% CI -0.60 to -0.80), 3.8 (95% CI 3.4-4.2) and 1.8 mL/s (95% CI 1.1-2.4) respectively, in favour of the combination group. The difference in PVR was not significant. There were no serious adverse events (AEs). The dropout rate due to AEs was 2.85%. Myalgia (five patients) was the commonest AE in the combination group.

CONCLUSION

The combination of tamsulosin and tadalafil produced significantly better improvements in LUTS, QoL, erectile function and Q_max compared to monotherapy with tamsulosin, without an increase in AEs.

Efficacy of Tamsulosin plus Tadalafil versus Tamsulosin as Medical Expulsive Therapy for Lower Ureteric Stones: A Randomized Controlled Trial

Introduction

Urolithiasis is one of the common disorder with which about 1/5^th is found in the ureter, of which 2/3^rd is seen in the lower ureter. Medical expulsive therapy is one of the routine modalities of treatment which uses various drugs acting on the ureter smooth muscle by different mechanism. We aim to compare the efficacy of combination vs. single drug.

Methods

This randomized controlled trial was done in 176 consecutive patients over a period of six months (March 2019 to August 2019) in Department of Urology and Kidney Transplant Surgery, Tribhuvan University Teaching. Participants were divided into two groups (Group A, tamsulosin plus tadalafil, and Group B, tamsulosin) from computer-generated random numbers. Therapy was continued for a maximum of 3 weeks. Stone expulsion rate, time to stone expulsion, analgesic use, number of colic and emergency room visits for pain, early intervention, and adverse effects of drugs were recorded.

Results

Among 176 patients who were enrolled in study, 7 were lost to follow-up, and 5 people required immediate intervention. There was a significant higher stone passage rate in group A than group B (64 vs. 50; P=0.025) and shorter expulsion time (1.66 vs. 2.32 weeks P=0.001) and less number of emergency room visits and colic episodes. No significant side effects were noted during study.

Conclusion

Tamsulosin plus Tadalafil is more effective than tamsulosin with early passage of stone and decreased number of colic episodes and emergency visits without significant side effects for lower ureteric calculi of 5 mm to 10 mm.

Effects of sildenafil citrate on peripheral fatigue and exercise performance after exhaustive swimming exercise in rats

Sildenafil citrate is a potent and selective inhibitor of phosphodiesterase type-5 used to treat erectile dysfunction. We investigated the effects of sildenafil citrate treatment on peripheral fatigue and exercise performance after exhaustive swimming exercise in rats. The rats in the sildenafil citrate-treated groups received sildenafil citrate orally once a day for 14 consecutive days at respective dosage. On the 14 days after starting experiment, each animal was submitted to swimming test with intensity equivalent to overload. The exhaustion was defined as a state in which coordinated movements did not return to the water surface for breathing within 10 sec. Western blot for monocarboxylate transporter (MCT)1, MCT4, and neuronal nitric oxide synthase (nNOS) were performed. Exhaustive swimming exercise decreased time of exhaustion and increased lactate concentration, however, sildenafil citrate enhanced time of exhaustion and decreased lactate concentration. Exhaustive swimming exercise increased MCT1 and MCT4 expressions in the gastrocnemius muscles and sildenafil citrate further enhanced MCT1 and MCT4 expressions in the exhaustive swimming exercise rats. Exhaustive swimming exercise decreased nNOS expression in the gastrocnemius muscles and sildenafil citrate enhanced nNOS expression in the exhaustive swimming exercise rats. The most potent effect appeared in the 20-mg/kg sildenafil citrate. Sildenafil citrate might be proposed as a potential ergogenic aid through antiperipheral fatigue.

Effect of sildenafil citrate on brain central fatigue after exhaustive swimming exercise in rats

Sildenafil citrate, a potent and selective inhibitor of phosphodiesterase type-5, is used clinically to treat erectile dysfunction and pulmonary arterial hypertension. We investigated the effect of sildenafil citrate on brain central fatigue through serotonin (5-hydroxytryptamine, 5-HT) synthesis after exhaustive swimming exercise in rats. The rats in the sildenafil citrate-treated groups received sildenafil citrate orally once a day for 14 consecutive days at respective dosage. On the 14 days after starting experiment, each animal was submitted to swimming test with intensity equivalent to overload. The exhaustion was defined as a state in which coordinated movements did not return to the water surface for breathing within 10 sec. Immunohistochemistry for 5-HT, tryptophan hydroxylase (TPH), and western blot for serotonergic type 1A (5-HT1_A) receptor and 5-HT transporter (5-HTT) were performed. Exhaustive swimming exercise increased 5-HT and TPH expressions in the dorsal raphe and sildenafil citrate suppressed 5-HT and TPH expressions in the exhaustive swimming exercise rats. Exhaustive swimming exercise increased 5-HT1_A receptor and 5-HTT expressions in the dorsal raphe and sildenafil citrate suppressed 5-HT1_A receptor and 5-HTT expressions in the exhaustive swimming exercise rats. The significant suppressing effect appeared in the 20-mg/kg sildenafil citrate. Sildenafil citrate might be proposed as a potential ergogenic aid through anticentral fatigue.

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

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

Testosterone treatment and cardiovascular events in prescription database studies

Over the past decade, there has been a substantial increase in the number of men who are treated with testosterone. Despite this increase in the use of testosterone, the risks of adverse cardiovascular events are unclear as meta-analyses have reported conflicting findings and no clinical studies have been large enough or long enough to adequately assess for cardiovascular risks. The goal of this paper is to review large prescription database studies of testosterone treatment and adverse cardiovascular events and mortality with the aim of providing some guidance for clinicians and researchers in this controversial area.

The association between cardiac resynchronization therapy response and sexual activity in patients with heart failure

BACKGROUND

Sexual activity is an important indicator of quality of life and is significantly impaired in patients with heart failure (HF). Cardiac resynchronization therapy (CRT) has positive effects on cardiac dysfunction and endothelial dysfunction that lead to erectile dysfunction (ED). We aimed to evaluate whether CRT may improve sexual activity in patients with HF.

METHODS

In total, 136 patients (mean age 61.8 ± 12.8 years) were evaluated for the study. All patients filled the Sexual Health Inventory for Men (SHIM) questionnaire for evaluation of their erectile functions before CRT device implantation. One hundred eighty days after CRT device implantation, the patients were re-evaluated with SHIM questionnaire.

RESULTS

In the whole study population, SHIM test scores were significantly increased after CRT (12.99 ± 3.22 vs. 18.03 ± 5.00; p<0.001). The patients were divided into two groups according to the CRT response. The increase in SHIM test scores was significantly more in the response (+) group than in the response (-) group [response (+) group: 6.94 ± 3.36; p<0.001 vs. response (-) group: 0.81 ± 1.77; p = 0.465]. A positive CRT response was found to be an independent predictor of SHIM score (p<0.001).

CONCLUSION

Our study showed that CRT had positive effects on ED of patients with HF.

Sexual Activity in Patients with Cardiac Diseases

SUMMARY – In this article, we outline the latest guidelines published by the American Heart Association on sexual activity in patients with coronary artery disease, heart failure, structural heart diseases, arrhythmias, implanted pacemakers or cardioverter defibrillators, as well as on treatment options of sexual dysfunction. Sexual activities are similar to mild/moderate physical activity during a short period. Most patients are recommended to involve in sexual activity after prior comprehensive evaluation of physical condition. Those with stable cardiac symptoms and good functional capacity are at a low risk of adverse cardiovascular events, and others require treatment or stabilization before involving in sexual activity. Stress testing is useful in evaluating safety of sexual activity in patients with questionable or undetermined risk. Treatment of sexual dysfunction includes counseling of patients and their sexual partners, and drug treatment with phosphodiesterase inhibitors (sildenafil, tadalafil, vardenafil) which have been demonstrated to be safe and effective, in men, and with serotonin reuptake inhibitors (flibanserin) and local vaginal estrogen administration in women. In conclusion, in routine clinical practice, patients should be approached individually and multidisciplinarily in order to detect and eliminate the factors that interfere with normal sexual activities and disturb the quality of life.

Efficacy and Safety of a Fixed-Dose Combination Therapy of Tamsulosin and Tadalafil for Patients With Lower Urinary Tract Symptoms and Erectile Dysfunction: Results of a Randomized, Double-Blinded, Active-Controlled Trial

BACKGROUND

Phosphodiesterase type 5 inhibitors and α-adrenergic blocking agents (α-blockers) are widely used for the treatment of erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH).

AIMS

To assess the efficacy and safety of fixed-dose combinations (FDCs) of tamsulosin and tadalafil compared with tadalafil monotherapy in patients with comorbid BPH-associated LUTS and ED.

METHODS

A randomized, double-blinded, active-controlled trial was conducted of 510 men with BPH-associated LUTS and ED. Patients were treated with FDCs of tamsulosin 0.4 mg plus tadalafil 5 mg (FDC 0.4/5 mg), tamsulosin 0.2 mg plus tadalafil 5 mg (FDC 0.2/5 mg), or tadalafil 5 mg for a 12-week treatment period. For a subsequent 12-week extension period, the patients were administered FDC 0.4/5 mg.

OUTCOMES

The primary outcomes were changes from baseline in total International Prostate Symptom Score (IPSS) and International Index of Erectile Function erectile function domain (IIEF-EF) score at week 12 to prove superiority and non-inferiority of FDCs compared with tadalafil 5 mg. The safety assessments were adverse reactions, laboratory test results, and vital signs at week 24.

RESULTS

The mean changes in total IPSS and IIEF-EF scores were -9.46 and 9.17 for FDC 0.4/5 mg and -8.14 and 9.49 for tadalafil 5 mg, respectively, which indicated superiority in LUTS improvement (P = .0320) and non-inferiority in ED treatment with FDC 0.4/5 mg compared with tadalafil 5 mg. However, the results from FDC 0.2/5 mg failed to demonstrate superiority in LUTS improvement. No clinically significant adverse events regarding the investigational products were observed during the 24-week period.

CLINICAL IMPLICATIONS

The FDC 0.4/5 mg is the first combined formulation of an α-blocker and a phosphodiesterase type 5 inhibitor that offers benefits in patient compliance and as add-on therapy in patients with comorbid BPH-associated LUTS and ED.

STRENGTHS AND LIMITATIONS

The study clearly demonstrated the advantage of FDC 0.4/5 mg. The main advantage of FDC 0.4/5 mg was the enhanced efficacy on BPH-associated LUTS comorbidity with ED, the lower incidence of side effects, and the simplification and convenience of therapy, which led to better overall patient compliance. However, the lack of a tamsulosin monotherapy control group was a limitation of this study.

CONCLUSION

The FDC 0.4/5 mg therapy was safe, well tolerated, and efficacious, indicating that combination therapy could provide clinical benefits for patients with BPH-associated LUTS complaints and ameliorate the comorbidity of ED. Kim SW, Park NC, Lee SW, et al. Efficacy and Safety of a Fixed-Dose Combination Therapy of Tamsulosin and Tadalafil for Patients With Lower Urinary Tract Symptoms and Erectile Dysfunction: Results of a Randomized, Double-Blinded, Active-Controlled Trial. J Sex Med 2017;14:1018-1027.

Targeting phosphodiesterase 5 as a therapeutic option against myocardial ischaemia/reperfusion injury and for treating heart failure

Phosphodiesterase type 5 (PDE5) selectively hydrolyses the second messenger cGMP into 5'-GMP, thereby regulating its intracellular concentrations. Dysregulation of the cGMP-dependent pathway plays a significant role in various cardiovascular diseases. Therefore, its modulation by drugs, such as PDE5 inhibitors, may represent an effective therapeutic approach. There are currently four PDE5 inhibitors available for the treatment of erectile dysfunction: sildenafil, vardenafil, tadalafil and avanafil. Sildenafil and tadalafil have also received Food and Drug Administration approval for the treatment of pulmonary arterial hypertension. This review summarizes the pharmacological aspects and clinical potential of PDE5 inhibition for the treatment of myocardial ischaemia/reperfusion injury and heart failure.

LINKED ARTICLES

This article is part of a themed section on Inventing New Therapies Without Reinventing the Wheel: The Power of Drug Repurposing. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.2/issuetoc.

Comparative Safety of Drugs Targeting the Nitric Oxide Pathway in Pulmonary Hypertension: A Mixed Approach Combining a Meta-Analysis of Clinical Trials and a Disproportionality Analysis From the World Health Organization Pharmacovigilance Database

BACKGROUND

Recent guidelines recommend riociguat, a soluble guanylate cyclase (sGC) stimulator, and the type 5 phosphodiesterase inhibitor (PDE5i) tadalafil or sildenafil as treatments for pulmonary arterial hypertension. We compared the safety profiles of sildenafil, tadalafil, and riociguat in pulmonary hypertension.

METHODS

We combined two approaches. First, we performed a meta-analysis of safety data extracted from randomized controlled trials. Second, we conducted a disproportionality analysis of data from VigiBase, the World Health Organization's global database of individual case safety reports, to compare the safety profiles with real-life data.

RESULTS

In the meta-analysis, a significant difference between the three drugs was only detected for gastrointestinal disorders, in disfavor of riociguat (P < .01 for interaction). In the disproportionality analysis, the use of riociguat was associated with fewer reports of visual disorders but increased reporting of gastrointestinal, hemorrhagic, and musculoskeletal disorders compared with sildenafil and tadalafil. Pharmacovigilance signals of hearing/vestibular disorders were heterogeneous: vestibular disorders (dizziness) were reported more frequently for riociguat, whereas hearing disorders (deafness) were reported less frequently compared with PDE5is.

CONCLUSIONS

The safety profiles of PDE5is and sGC stimulators significantly differ in pulmonary hypertension. Accordingly, there is a safety rationale in switching between PDE5is and sGC stimulators because of their different side effects.

TRIAL REGISTRY

PROSPERO; No.: CRD42016051986; URL: https://www.crd.york.ac.uk/prospero/.

The Role of Nitroglycerin and Other Nitrogen Oxides in Cardiovascular Therapeutics

The use of nitroglycerin in the treatment of angina pectoris began not long after its original synthesis in 1847. Since then, the discovery of nitric oxide as a biological effector and better understanding of its roles in vasodilation, cell permeability, platelet function, inflammation, and other vascular processes have advanced our knowledge of the hemodynamic (mostly mediated through vasodilation of capacitance and conductance arteries) and nonhemodynamic effects of organic nitrate therapy, via both nitric oxide-dependent and -independent mechanisms. Nitrates are rapidly absorbed from mucous membranes, the gastrointestinal tract, and the skin; thus, nitroglycerin is available in a number of preparations for delivery via several routes: oral tablets, sublingual tablets, buccal tablets, sublingual spray, transdermal ointment, and transdermal patch, as well as intravenous formulations. Organic nitrates are commonly used in the treatment of cardiovascular disease, but clinical data limit their use mostly to the treatment of angina. They are also used in the treatment of subsets of patients with heart failure and pulmonary hypertension. One major limitation of the use of nitrates is the development of tolerance. Although several agents have been studied for use in the prevention of nitrate tolerance, none are currently recommended owing to a paucity of supportive clinical data. Only 1 method of preventing nitrate tolerance remains widely accepted: the use of a dosing strategy that provides an interval of no or low nitrate exposure during each 24-h period. Nitric oxide's important role in several cardiovascular disease mechanisms continues to drive research toward finding novel ways to affect both endogenous and exogenous sources of this key molecular mediator.

Drug-related problems in patients with erectile dysfunctions and multiple comorbidities

This study was conducted in a tertiary medical center in Kuala Lumpur, Malaysia. A total of 200 erectile dysfunction (ED) patients with 499 cases who had received pharmacological treatments for their ED participated in this study. Types, causes and factors associated with drug-related problems (DRPs) in ED patients with multiple comorbidities were assessed. A total of 244 DRPs with an average of 1.2±2.1 DRPs per patient were identified. Drug interaction contributed the most to DRPs occurrence. There was a significant higher risk of DRPs in patients with benign prostatic hyperplasia, lower urinary tract infection and elderly and end-stage renal disease. Early identification of types of DRPs and factors associated may enhance their prevention and management.

The risk of cardiovascular side effects with anti-anginal drugs

INTRODUCTION

Angina pectoris is a common presenting symptom of underlying coronary artery disease or reduced coronary flow reserve. Patients with angina have impaired quality of life; and need to be treated optimally with antianginal drugs to control symptoms and improve exercise performance. A wide range of antianginal medications are approved for the treatment of angina, and often more than one class of antianginal drugs are used to adequately control the symptoms. This expert opinion highlights the likely cardiac adverse effects of available antianginal drugs, and how to minimize these in individual patients and especially during combination treatment. Areas covered: All approved antianginal drugs, including the older and newly approved medications with different mechanism of action to the older drugs as well as some of the unapproved herbal medications. The safety profiles and potential cardiac side effects of these medications when used as monotherapy or as combination therapy are discussed and highlighted. Expert opinion: Because of the different cardiac safety profiles and possible side effects, we recommend selection of initial drug or adjustment of therapy based on the resting heart rate; blood pressure, hemodynamic status; and resting left ventricular function, concomitant medications and any associated comorbidities.

Is the use of plants in Jordanian folk medicine for the treatment of male sexual dysfunction scientifically based? Review of in vitro and in vivo human and animal studies

Male sexual dysfunction is a serious problem which has an impact on the quality of life. In Jordanian folk medicine, 56 plant species were reported to be used by males to improve sexual potency and as aphrodisiacs. The aim of this study was to search for scientific evidence justifying their folk use. Of the 15 studied plants, only five were found to enhance spermatogenesis. The other 10 were reported to decrease spermatogenesis at least by one study. The majority of the studied plants possessed a protective effect on testis in different in vivo models as well as antioxidant activities. The effect of these plants on steroidogenesis and the hypothalamic-gonadal axis was also reviewed. The effect of only five plants was studied on sexual behaviour enhancement and three of them were active. Three of the four studied plants enhanced erection. The mechanism of action of active constituents isolated from the studied plants was also investigated. In conclusion, many plants used in Jordanian folk medicine decreased or had no effect on spermatogenesis in animal models. These plants have antioxidant and/or adaptogenic effects, and this may result in a beneficial action on male reproductive system.

Sexual counseling and cardiovascular disease: practical approaches

Patients with cardiovascular disease and their partners expect health care providers to provide sexual counseling to assist them in maintaining sexual quality of life. Evidence suggests however, that there is a gap in integrating evidence into practice and that relatively few cardiac patients receive sexual counseling. This can result in negative psychological, physical, and quality of life outcomes for couples who may needlessly decide sexual activity is too risky and cease all sexual activity. Two scientific statements now exist that provide ample guidance to health care providers in discussing this important topic. Using a team approach that includes physicians, nurses, physical therapists, rehabilitation staff, and others is important to ensure that sexual counseling occurs throughout recovery. In addition, several trials using interventional approaches for sexual counseling provide insight into successful approaches for sexual counseling in practice. This article provides practical strategies and evidence-based approaches for assessment and sexual counseling for all cardiac patients and their partners, and specific counseling for those with ischemic conditions, heart failure, and implanted devices.

Cardioprotective role of tadalafil against cisplatin-induced cardiovascular damage in rats

The present study investigated the possible cardioprotective effect of tadalafil (Tad) on cisplatin (CDDP)-induced cardiac and vascular damages in rats. A total number of seventy two healthy male albino rats initially weighting between 200 and 220 g were used and randomly divided into four groups,18 rats in each. The control group received no treatment; CDDP group received a single dose of CDDP (4 mg/kg) intraperitoneal (i.p.) per week for 4 weeks the duration of the experiment; Tad group received 0.4 mg/kg BW Tad i.p. daily and Tad +CDDP group received 0.4 mg/kg BW Tad i.p. +4 mg/kg BW CDDP i.p. The results showed that Tad was able to decrease blood pressure, heart rate, levels of serum cardiac troponin (cTn-I), malondialdehyde (MDA) and increased levels of reduced glutathione (GSH) and nitric oxide (NO) in the heart homogenate sample from CDDP treated rats. Semi-quantitative analysis showed that Tad was able to decrease the histopathological scores of cardiac muscular hyalinzation and fibrosis in three sacrifices in CDDP treated rats. CDDP treated rats showed significantly increased thickening in wall of aorta with an irregular luminal layer of endothelial cell linings in three sacrifices when it was compared to other groups. Moreover, immunohistochemical labeling of α- smooth muscle actin (α-SMA) in aorta revealed significant lower scores in Tad +CDDP group when they were compared to CDDP group. In conclusion, Tad alone did not induce any harmful effects on blood pressure, selective antioxidant, peroxidation markers or cardiac histology, in addition, Tad has a cardio-protective role against CDDP.

An Observational Study to Evaluate the Prevalence of Erectile Dysfunction (ED) and Prescribing Pattern of Drugs in Patients with ED Visiting an Andrology Specialty Clinic, Mumbai: 2012-14

INTRODUCTION

Erectile dysfunction (ED) is a common occurrence and its incidence is expected to increase significantly along with the increase in various lifestyle diseases. The drug utilization for ED is very low. Also, studies describing the prescription pattern in ED are lacking.

MATERIALS AND METHODS

We conducted a retrospective cross-sectional observational study, including a drug utilization analysis, of 606 prescriptions as per the standard guidelines (WHO and STROBE).

RESULTS

Out of 606, 249 (41%) were from the age group of 30-39 years. Addictions were present in 388 (64%). Out of 606, 186 had urological, 154 had cardiovascular and 102 had psychological co-morbid disorders. Out of 348, 201 were prescribed Tadalafil (low dose) on a once daily basis. Out of 172, 121 were prescribed Sildenafil (high dose) on an 'as and when required' basis. Nutritional/ herbal supplements were prescribed in 126/606. The ratio of 'Prescribed Daily Dose' to 'Defined Daily Dose' of Tadalafil, Sildenafil, and Dapoxetine were 1.1, 1.3 and 1.5 respectively.

CONCLUSION

Measures for de-addiction play an important role in the overall management of ED. The most common co-morbid disorders were urological, like BPH, LUTS, etc, followed by cardiovascular, psychological and diabetes. Overall, rational pharmacotherapy was observed. Tadalafil was the most commonly prescribed drug for ED. The main factor in the selection of a particular PDE5 inhibitor was its pharmacokinetics and cost. Udenafil, being the costliest, was the least prescribed. Dapoxetine was used in a significant number of individuals primarily for PE with ED. The combination of Papaverine, Chlorpromazine ± Alprostadil was used as intracavernosal injection in patients not responding to oral drugs.

Stimulation of soluble guanylyl cyclase protects against obesity by recruiting brown adipose tissue

Obesity is characterized by a positive energy balance and expansion of white adipose tissue (WAT). In contrast, brown adipose tissue (BAT) combusts energy to produce heat. Here we show that a small molecule stimulator (BAY 41-8543) of soluble guanylyl cyclase (sGC), which produces the second messenger cyclic GMP (cGMP), protects against diet-induced weight gain, induces weight loss in established obesity, and also improves the diabetic phenotype. Mechanistically, the haeme-dependent sGC stimulator BAY 41-8543 enhances lipid uptake into BAT and increases whole-body energy expenditure, whereas ablation of the haeme-containing β1-subunit of sGC severely impairs BAT function. Notably, the sGC stimulator enhances differentiation of human brown adipocytes as well as induces 'browning' of primary white adipocytes. Taken together, our data suggest that sGC is a potential pharmacological target for the treatment of obesity and its comorbidities.

Management of erectile dysfunction post-radical prostatectomy

Radical prostatectomy is a commonly performed procedure for the treatment of localized prostate cancer. One of the long-term complications is erectile dysfunction. There is little consensus on the optimal management; however, it is agreed that treatment must be prompt to prevent fibrosis and increase oxygenation of penile tissue. It is vital that patient expectations are discussed, a realistic time frame of treatment provided, and treatment started as close to the prostatectomy as possible. Current treatment regimens rely on phosphodiesterase 5 inhibitors as a first-line therapy, with vacuum erection devices and intraurethral suppositories of alprostadil as possible treatment combination options. With nonresponders to these therapies, intracavernosal injections are resorted to. As a final measure, patients undergo the highly invasive penile prosthesis implantation. There is no uniform, objective treatment program for erectile dysfunction post-radical prostatectomy. Management plans are based on poorly conducted and often underpowered studies in combination with physician and patient preferences. They involve the aforementioned drugs and treatment methods in different sequences and doses. Prospective treatments include dietary supplements and gene therapy, which have shown promise with there proposed mechanisms of improving erectile function but are yet to be applied successfully in human patients.

The role of statins in erectile dysfunction: a systematic review and meta-analysis

To evaluate the effect of statins for erectile dysfunction (ED), a systematic review of the literature was conducted in the Cochrane Library, Embase and PubMed from the inception of each database to June 2013. Only randomized controlled trials (RCTs) comparing treatment for ED with statins were identified. Placebo RCTs with the International Index of Erectile Function (IIEF) as the outcome measure were eligible for meta-analysis. A total of seven RCTs including two statins with a total of 586 patients strictly met our criteria for systematic review and five of them qualified for the meta-analysis. A meta-analysis using a random effects model showed that statins were associated with a significant increase in IIEF-5 scores (mean difference (MD): 3.27; 95% confidential interval (CI):1.51 to 5.02; P < 0.01) and an overall improvement of lipid profiles including total cholesterol (MD: −1.08; 95% CI: −1.68 to −0.48; P < 0.01), low-density lipoprotein (LDL) cholesterol (MD: −1.43; 95% CI: −2.07 to −0.79; P < 0.01), high-density lipoprotein (HDL) cholesterol (MD: 0.24; 95% CI: 0.13 to 0.35; P < 0.01) and triglycerides (TGs) (MD: −0.55; 95% CI: −0.61 to −0.48; P < 0.01). In summary, our study revealed positive consequences of these lipid-lowering drugs on erectile function, especially for nonresponders to phosphodiesterase type 5 inhibitors (PDE5Is). However, it has been reported that statin therapy may reduce levels of testosterone and aggravate symptoms of ED. Therefore, larger, well-designed RCTs are needed to investigate the double-edged role of statins in the treatment of ED.

Optic neuropathy associated with the use of over-the-counter sexual enhancement supplements

This case report details an association of the use of over-the-counter sexual enhancement supplements with atypical optic neuropathy. A 42-year-old man presented with right-sided headache and vision loss of the right eye, which deteriorated to a single quadrant of hand motion over 11 days. Serial orbital magnetic resonance imaging scans demonstrated progressive orbital optic nerve enhancement extending into the optic canal despite high-dose steroid treatment. The patient eventually admitted to using several over-the-counter sexual enhancement supplements prior to the onset of symptoms and throughout the course of his steroid treatment, which he subsequently discontinued. His vision improved to 20/200 with an expanded visual field. Anterior ischemic optic neuropathy has been reported in association with phosphodiesterase (PDE)-5 inhibitor use, but visual loss in association with unregulated sexual enhancement supplements has not been studied. While one case cannot establish association, our case is suggestive of potential dangers of over-the-counter sexual enhancement supplements, which may contain PDE-5 inhibitors, “male hormones,” and “substances that enhance blood production.” The case also underscores the importance of obtaining a careful history of supplements in patients with optic neuropathies.

Challenges with nitrate therapy and nitrate tolerance: prevalence, prevention, and clinical relevance

Nitrate therapy has been an effective treatment for ischemic heart disease for over 100 years. The anti-ischemic and exercise-promoting benefits of sublingually administered nitrates are well established. Nitroglycerin is indicated for the relief of an established attack of angina and for prophylactic use, but its effects are short lived. In an effort to increase the duration of beneficial effects, long-acting orally administered and topical applications of nitrates have been developed; however, following their continued or frequent daily use, patients soon develop tolerance to these long-acting nitrate preparations. Once tolerance develops, patients begin losing the protective effects of the long-acting nitrate therapy. By providing a nitrate-free interval, or declining nitrate levels at night, one can overcome or reduce the development of tolerance, but cannot provide 24-h anti-anginal and anti-ischemic protection. In addition, patients may be vulnerable to occurrence of rebound angina and myocardial ischemia during periods of absent nitrate levels at night and early hours of the morning, and worsening of exercise capacity prior to the morning dose of the medication. This has been a concern with nitroglycerin patches but not with oral formulations of isosorbide-5 mononitrates, and has not been adequately studied with isosorbide dinitrate. This paper describes problems associated with nitrate tolerance, reviews mechanisms by which nitrate tolerance and loss of efficacy develop, and presents strategies to avoid nitrate tolerance and maintain efficacy when using long-acting nitrate formulations.

Comparative efficacy of tamsulosin versus tamsulosin with tadalafil in combination with prednisolone for the medical expulsive therapy of lower ureteric stones: a randomized trial

PURPOSE

To compare the safety and efficacy of tamsulosin and tamsulosin with the phosphodiesterase-5 inhibitor tadalafil in combination with prednisolone as medical expulsive therapies for lower ureteric stones.

MATERIALS AND METHODS

Between July 2011 and December 2012, 62 adult patients presenting with distal ureteric stones sized 5 to 10 mm were randomized equally to treatment with tamsulosin (group A) or tamsulosin with tadalafil (group B). Therapy was given for a maximum of 6 weeks. In addition, patients in groups A and B were given 5-mg prednisolone once daily (maximum 1 week). The stone expulsion rate, time to stone expulsion, analgesic use, number of hospital visits for pain, follow-up and endoscopic treatment, and adverse effects of the drugs were noted. Statistical analyses were done by using Student t-test and chi-square test.

RESULTS

There was a higher expulsion rate (83.9% in group B and 74.2% in group A) and a lower time to expulsion in both treatment groups than in historical controls used in earlier studies. However, these results were not statistically significant (p=0.349, p=0.074, respectively). Statistically significant differences were noted in hospitalization for colic and analgesic requirement, which were less in group B than in group A. There were no serious adverse events. Another important finding was improvement in erectile function in group B.

CONCLUSIONS

Medical expulsive therapy for distal ureteric stones using tamsulosin and tadalafil with prednisolone is safe and efficacious. Also, the prescription of tadalafil in cases of erectile dysfunction with the development of lower ureteric stones may provide additional advantages.

A comparative randomized prospective study to evaluate efficacy and safety of combination of tamsulosin and tadalafil vs. tamsulosin or tadalafil alone in patients with lower urinary tract symptoms due to benign prostatic hyperplasia

INTRODUCTION

Lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) and erectile dysfunction are common disorders of advancing age.

AIM

To evaluate the efficacy and safety of tamsulosin and tadalafil in patients with LUTS due to BPH.

METHODS

In this prospective randomized study, 133 men complaining of LUTS due to BPH were included. Forty-five patients received tamsulosin 0.4 mg/day alone (Group A), 44 patients received tadalafil 10 mg/day (Group B), and combination therapy (tamsulosin and tadalafil both) was instituted in 44 patients (Group C). After a 2-week medication free run-in period, they were evaluated for International Prostatic Symptom Score (IPSS), International Index of Erectile Function score (IIEF5), quality of life (IPSS QoL), maximum urinary flow rate (Qmax), post-void residual urine (PVR) volume, and safety parameters before and at 3 months of treatment.

MAIN OUTCOME MEASURES

There were primary (IPSS, IPSS QoL index, Qmax, and PVR) and secondary (erectile function [EF] domain scores from IIEF5) efficacy end points. Safety assessment included laboratory tests and patient's reporting of adverse event.

RESULTS

A significant improvement in IPSS score was observed in all the 3 groups A, B, and C (-50.90%, P < 0.05; -33.50%, P < 0.05; and -53.90%, P < 0.05, respectively). IIEF5 score increased significantly in these three groups (+39.28%, P < 0.05; +45.96%, P < 0.05; and +60.23%, P < 0.05, respectively). A significant increase in Qmax and decrease in PVR were also observed (33.99%, P < 0.05; 29.78%, P < 0.05; and 37.04%, P < 0.05) and (-60.90%, P < 0.05; -49.45%, P < 0.05; and -62.97%, P < 0.05, respectively). The QoL scores improved significantly (-73.35%, P < 0.05; -70.26%, P < 0.05; and -79.65%, P < 0.05, respectively). Side effects were dyspepsia, heartburn, headache, flushing, myalgia, and backache. Adverse effect dropout was 3.7%. No participant experienced any severe or serious adverse events.

CONCLUSIONS

In patients with LUTS due to BPH, tamsulosin and tadalafil alone or in combination cause a significant improvement in patients with LUTS. Their EF also improves with these medications. The improvement is better with combination therapy compared with single agent alone.

Effects of sildenafil on the gastrocnemius and cardiac muscles of rats in a model of prolonged moderate exercise training

Moderate exercise training improves energetic metabolism, tissue perfusion and induces cardiac and skeletal muscle remodeling. Sildenafil, a potent phosphodiesterase-5 inhibitor used to treat erectile dysfunction, reduces infarct size and increases tissue oxygenation in experimental models of cardiovascular disease. We have evaluated the effects of prolonged moderate exercise training and a repeat administration of sildenafil on the rat gastrocnemius and cardiac muscles. Animals were divided into two groups: sedentary and trained. Each group was subdivided into animals treated with vehicle or with two doses of sildenafil (10 or 15 mg/kg/day) during the last week of training. Physical exercise did not induce cardiac hypertrophy, whereas it increased mRNA levels of the PGC-1α, HIF-1α and VEGF genes, which are involved in mitochondrial biogenesis and angiogenesis, and reduced mRNA levels of FoxO3a, MuRF-1 and Atrogin-1. Sildenafil dose-dependently promoted both angiogenesis, as shown by increased capillary density, and muscle atrophy, as shown by muscle fibre size. These effects were more pronounced in trained animals. Our data confirm the beneficial effects of a moderate and prolonged training on cardiovascular and skeletal systems and document the positive and negative effects of sildenafil on these tissues at doses higher than those used in clinical practice. This report may impact on the use of sildenafil as a substance able to influence sports performance.

Role of phosphodiesterase-5 inhibitors in heart failure: emerging data and concepts

Novel treatment of congestive heart failure (HF) involves utilizing unique pathways to improve upon contemporary therapies. Increasing the availability of cyclic guanosine monophosphate (cGMP) by inhibition of phosphodiesterase-5 (PDE5) is a relatively new, but promising therapeutic strategy. Preclinical studies suggest a favorable myocardial effect of PDE5 inhibitors by blocking adrenergic, hypertrophic and pro-apoptotic signaling, thereby supporting their use in HF. The clinical benefits of acute and chronic PDE5 inhibition on lung diffusion capacity, exercise performance and ejection fraction in humans are emerging and appear promising. Larger, controlled trials are now on-going to assess the safety, efficacy and tolerability of PDE5 inhibitors on morbidity and mortality in patients with both systolic and diastolic heart failure. If the results of these trials are positive, a new avenue for the treatment of HF will open, which will help curtail the societal effects of this costly and morbid disease.

Sexual function in patients with chronic angina pectoris

Drugs for erectile dysfunction (ED) may be contraindicated with nitrates commonly used to treat patients with angina pectoris, and certain antianginal therapies may worsen ED. The American Heart Association and the Princeton Consensus Conference panel of experts recommend that patients with coronary artery disease and ED who experience angina pectoris undergo full medical evaluations to assess the cardiovascular risks associated with resuming sexual activity before being prescribed therapy for ED. Current antianginal therapies include β blockers, calcium channel blockers, short- and long-acting nitrates, and ranolazine, a late sodium current inhibitor. Short- and long-acting nitrates remain a contraindication with phosphodiesterase-5 inhibitors commonly used to treat patients with ED, and the benefits of the other antianginal therapies must be weighed against their effects on cardiovascular health and erectile function. In conclusion, patients with coronary artery disease and ED who wish to initiate phosphodiesterase-5 inhibitor therapy and need to discontinue nitrate therapy need treatment options that manage their angina pectoris effectively, maintain their cardiovascular health, and provide the freedom to maintain their sexual function.