Alprostadil for the treatment of impotence

The effect of topical and intraurethral alprostadil on erectile function: A systematic review and meta-analysis

BACKGROUND

Erectile dysfunction (ED) affects up to 50% of men over 40. While phosphodiesterase-5 inhibitors (PDE5i) are the first line of medical treatment, they are not always effective. Alprostadil, available in injectable, topical, and intraurethral forms, offers an alternative treatment modality.

OBJECTIVES

This systematic review and meta-analysis aim to evaluate the efficacy and safety of topical and intraurethral forms of alprostadil.

MATERIALS AND METHODS

The objectives and methods of this systematic review and meta-analysis were predefined in a protocol registered on PROSPERO (CRD42021260894). We systematically searched PubMed, EMBASE, and the Cochrane Library up to April 2024. Using a random-effects model, we compared the efficacy of topical and intraurethral forms of alprostadil against placebo. Additionally, we performed a qualitative assessment of the studies using RoB-2 and ROBINS-I tools.

RESULTS

The analysis included 11 randomized controlled trials and 4 non-randomized studies, encompassing 5869 patients with a mean age of 60 ± 9.4 years. The meta-analysis showed a statistically significant improvement in the IIEF score by 4.7 points (95% CI: 2.4-7.1, I2 = 97%) in patients using the topical form of alprostadil compared to placebo. There was also a statistically significant improvement of ED in patients using intraurethral alprostadil compared to placebo, with a pooled odds ratio of 0.08 (95% CI: 0.04-0.16, I2 = 54%). The most common adverse events reported were penile pain and erythema.

DISCUSSION

These results are limited by the variability in study designs and the relatively small number of included studies in the meta-analysis. Moreover, the low methodological quality of the included studies further limits the strength of the conclusions.

CONCLUSIONS

Topical and intraurethral alprostadil significantly improve ED symptoms compared to placebo and are generally safe, with no serious adverse events. Further trials are necessary to confirm and expand on these findings.

Investigation into the molecular mechanisms of biomarkers in psoriasis vulgaris with reduced high-density lipoprotein levels based on bulk transcriptome sequencing data

It has been found that severe lipid metabolism disorders are often present in patients with Psoriasis, including decreased levels of high-density lipoprotein (HDL). This study initially explored the impact of HDL level variations on psoriasis by collecting. This study collected 12 blood samples and 9 skin samples from psoriasis vulgaris and psoriasis vulgaris with reduced HDL levels and performed bulk RNA sequencing. The genes expressed explicitly in both tissue and blood samples from psoriasis vulgaris patients with low HDL levels were selected to explore their molecular regulation in psoriasis vulgaris further, to elucidate the pathogenesis of psoriasis. A total of 421 specific DEGs in blood and 143 specific DEGs in skin from PN groups were obtained, and these genes were enriched in the terms and pathways related to inflammation and immune system. Also, biomarkers were screened out with same expression pattern in both blood and skin samples. Five intersecting differential genes (METRNL, NDEL1, HLA-DRA, MZB1, MKRN3) were obtained. Their function was further predicted. In conclusion, our research identified five biomarkers in psoriasis that are associated with low HDL levels. Furthermore, our findings revealed that alterations in HDL levels in psoriasis may exacerbate the clinical manifestations of psoriasis through regulation of immune response and lipid metabolism.

Branched-chain amino acids levels associated with risk of erectile dysfunction: A Mendelian randomization analysis

BACKGROUND

Erectile dysfunction (ED) is a prevalent male sexual dysfunction that remarkably impacts patients' quality of life and is also recognized as a precursor to cardiovascular disease (CVD) events. Branched-chain amino acids (BCAAs) are derived from dietary intake and mainly involved in energy metabolism. Previous studies have underscored the association between BCAAs and CVD, but the causal link between BCAAs and ED remains uncertain.

METHODS

The bidirectional Mendelian randomization (MR) study used the genetic data from genome-wide association studies (GWAS) to identify single nucleotide polymorphisms (SNPs) associated with total BCAAs, leucine, isoleucine, and valine. The genetic data for ED were acquired from the FinnGen study (n = 95,178). The primary method used to assess causal associations was the inverse variance-weighted (IVW) method, supplemented by MR-Egger, weighted median, and simple median analyses. Cochrane's Q test was utilized to evaluate heterogeneity within the results, while the MR-Egger intercept test was utilized to evaluate the Level pleiotropy. A sensitivity analysis was performed employing leave-one-out analysis.

RESULTS

The MR analysis results indicate a positive correlation between levels of total BCAA (OR = 1.984, 95 % CI = 1.018-3.868, P = 0.044), leucine (OR = 2.277, 95 % CI = 1.121-4.626, P = 0.023), isoleucine (OR = 2.584, 95 % CI = 1.167-5.722, P = 0.019), valine (OR = 1.894, 95 % CI = 1.119-3.206, P = 0.017), and the risk of ED. Sensitivity tests confirmed the accuracy and robustness of the study findings. Moreover, the reverse MR analysis found no association between ED and the BCAAs.

CONCLUSION

The results of this analysis indicate a positive association between the circulating BCAA concentrations and the risk of ED, but their underlying mechanisms require further investigation.

Prostaglandins as a Topical Therapy for Erectile Dysfunction: A Comprehensive Review

INTRODUCTION

Erectile dysfunction (ED) is a substantial cause of dissatisfaction among many men. This discontentment has led to the emergence of various drug treatment options for this problem.

OBJECTIVES

Unfortunately, due to various interactions, contraindications, and side effects, systemic therapies such as phosphodiesterase-5 inhibitors (including sildenafil, tadalafil, vardenafil, avanafil, etc.) are not welcomed in many patients. These problems have led researchers to look for other ways to reduce these complications.

METHODS

This article holistically reviews the efficacy of topical prostaglandins and their role in treating ED. We sought to provide a comprehensive overview of recent findings on the current topic by using the extensive literature search to identify the latest scientific reports on the topic.

RESULTS

In this regard, topical and transdermal treatments can be suitable alternatives. In diverse studies, prostaglandins, remarkably PGE1 (also known as alprostadil), have been suggested to be an acceptable candidate for topical treatment.

CONCLUSION

Numerous formulations of PGE1 have been used to treat patients so far. Still, in general, with the evolution of classical formulation methods toward modern techniques (such as using nanocarriers and skin permeability enhancers), the probability of treatment success also increases.

Efficacy Evaluation of Plant Products in the Treatment of Erectile Dysfunction Related to Diabetes

Erectile dysfunction affects more than 50% of diabetic male patients, with a higher prevalence compared with the general population. Age, clinical factors, and lifestyle habits have been suggested to contribute to the pathophysiology and worsening of erectile dysfunction in diabetic patients. First- and second-line standard treatments are represented by phosphodiesterase type 5 (PDE5) inhibitors and alprostadil, respectively. However, natural compounds have been suggested to ameliorate this clinical condition. This study aims to preclinically characterize the potential synergism among plant-derived products for the improvement of erectile dysfunction in the diabetic condition. The effects of a nutritional supplement composed of Panax ginseng, Moringa oleifera and rutin, as single agents or as a mixture, were evaluated in a streptozotocin (STZ)-induced diabetic rat model with erectile dysfunction. The treatment efficacy was evaluated by measuring sexual-related parameters (i.e., mount and intromission latencies, the mount and intromission frequencies and the ejaculation latency). Results showed that only the mixture was able to significantly reduce the diabetes-related delay in mount latency (p < 0.01). Substantial similar effects were observed by measuring the intromission latency and the mean number of mounts was very similar between rats treated with the mixture and controls. Single agent treatments showed very low effects in terms of intromission frequency, whereas the mixture was able to increase this parameter. Additionally, a statistically significant reduced ejaculation latency was observed in rats treated with the mixture compared with the STZ control. These results are in agreement with the available literature and suggest that the study mixture may ameliorate sexual behavior compared with the administration of the study natural compounds as single agents in diabetic rats. Further preclinical and clinical studies are needed to perform a more comprehensive evaluation of the efficacy and safety of the study mixture.

Dose-Dependent Effects of a Novel Selective EP4 Prostaglandin Receptor Agonist on Treatment of Critical Size Femoral Bone Defects in a Rat Model

Difficulties in treating pseudarthrosis and critical bone defects are still evident in physicians’ clinical routines. Bone morphogenetic protein 2 (BMP-2) has shown promising osteoinductive results but also considerable side effects, not unexpected given that it is a morphogen. Thus, the bone regenerative potential of the novel selective, non-morphogenic EP₄ prostaglandin receptor agonist KMN-159 was investigated in this study. Therefore, mineralized collagen type-1 matrices were loaded with different amounts of BMP-2 or KMN-159 and implanted into a 5 mm critical-sized femoral defect in rats. After 12 weeks of observation, micro-computed tomography scans were performed to analyze the newly formed bone volume (BV) and bone mineral density (BMD). Histological analysis was performed to evaluate the degree of defect healing and the number of vessels, osteoclasts, and osteoblasts. Data were evaluated using Kruskal-Wallis followed by Dunn’s post hoc test. As expected, animals treated with BMP-2, the positive control for this model, showed a high amount of newly formed BV as well as bone healing. For KMN-159, a dose-dependent effect on bone regeneration could be observed up to a dose optimum, demonstrating that this non-morphogenic mechanism of action can stimulate bone formation in this model system.

Intravesical alprostadil as a promising agent in BK virus-associated hemorrhagic cystitis: A report of a refractory case

Allogeneic stem cell transplant recipients are at risk of BK virus-associated hemorrhagic cystitis. This condition causes a significant morbidity and worsens clinical outcomes. The standard cares for BK virus-associated hemorrhagic cystitis are saline irrigation and forced diuresis. Notably, several beneficial roles are proposed for antiviral and anti-inflammatory agents against BK virus-associated hemorrhagic cystitis. However, cases who are at risk of cystectomy remain refractory. Herein, we present a 13-year-old boy with severe hematuria by passing two months from his allogeneic stem cell transplantation. The laboratory work up showed high BK viremia >1.1 ×  10⁸ copies/ml in this case's urine sample. The patient was treated with antiviral agents in combination with supportive care. Moreover, intravesical alum was administered, but no clinical benefits were achieved. Finally, intravesical alprostadil was prepared under the supervision of a pediatric clinical pharmacist. In this regard, an alprostadil solution was prepared by constitution of 250 μg alprostadil in 50 mL saline. After administrating the first dose of intravesical alprostadil, an acceptable clinical response was observed, and hematuria stopped. Of note, alprostadil induces platelet aggregation and vasoconstriction. Thus, bleeding can be controlled after the administration of intravesical alprostadil. This strategy may be associated with several side effects including bladder spasm. This study is the first report describing the special role of intravesical alprostadil in refractory cases of BK virus-associated hemorrhagic cystitis. In such refractory cases, clinicians can use intravesical alprostadil rather than invasive therapies in the treatment of BK virus-hemorrhagic cystitis.

The wHole Story About Fenestrations in LSEC

The porosity of liver sinusoidal endothelial cells (LSEC) ensures bidirectional passive transport of lipoproteins, drugs and solutes between the liver capillaries and the liver parenchyma. This porosity is realized via fenestrations - transcellular pores with diameters in the range of 50-300 nm - typically grouped together in sieve plates. Aging and several liver disorders severely reduce LSEC porosity, decreasing their filtration properties. Over the years, a variety of drugs, stimulants, and toxins have been investigated in the context of altered diameter or frequency of fenestrations. In fact, any change in the porosity, connected with the change in number and/or size of fenestrations is reflected in the overall liver-vascular system crosstalk. Recently, several commonly used medicines have been proposed to have a beneficial effect on LSEC re-fenestration in aging. These findings may be important for the aging populations of the world. In this review we collate the literature on medicines, recreational drugs, hormones and laboratory tools (including toxins) where the effect LSEC morphology was quantitatively analyzed. Moreover, different experimental models of liver pathology are discussed in the context of fenestrations. The second part of this review covers the cellular mechanisms of action to enable physicians and researchers to predict the effect of newly developed drugs on LSEC porosity. To achieve this, we discuss four existing hypotheses of regulation of fenestrations. Finally, we provide a summary of the cellular mechanisms which are demonstrated to tune the porosity of LSEC.

Alternative Treatment for Erectile Dysfunction: a Growing Arsenal in Men's Health

PURPOSE OF REVIEW

To highlight and review encouraging preliminary studies behind several alternative products and interventions for erectile dysfunction (ED).

RECENT FINDINGS

Alternative treatments for ED are becoming more prevalent with increased consumer interest. "Natural" products are sold online, and numerous clinics offer various off-label and investigational interventions. These alternative treatments have demonstrated varying degrees of efficacy in randomized trials and meta-analyses, but none of these interventions has robust enough evidence to be considered first-line therapy. These treatments may find a role in combination with guideline treatments or may be used in novel penile rehabilitation research protocols. With growing interest in alternative treatment for men's health, an awareness of the literature is imperative for patient counsel. Alternative treatments, like L-arginine, have a growing body of evidence for efficacy in combination with PDE5i, and low-intensity shock wave therapy and stem cell therapy continue to demonstrate encouraging outcomes in ED trials.

International Union of Basic and Clinical Pharmacology. CIX. Differences and Similarities between Human and Rodent Prostaglandin E2 Receptors (EP1-4) and Prostacyclin Receptor (IP): Specific Roles in Pathophysiologic Conditions

Prostaglandins are derived from arachidonic acid metabolism through cyclooxygenase activities. Among prostaglandins (PGs), prostacyclin (PGI2) and PGE2 are strongly involved in the regulation of homeostasis and main physiologic functions. In addition, the synthesis of these two prostaglandins is significantly increased during inflammation. PGI2 and PGE2 exert their biologic actions by binding to their respective receptors, namely prostacyclin receptor (IP) and prostaglandin E2 receptor (EP) 1-4, which belong to the family of G-protein-coupled receptors. IP and EP1-4 receptors are widely distributed in the body and thus play various physiologic and pathophysiologic roles. In this review, we discuss the recent advances in studies using pharmacological approaches, genetically modified animals, and genome-wide association studies regarding the roles of IP and EP1-4 receptors in the immune, cardiovascular, nervous, gastrointestinal, respiratory, genitourinary, and musculoskeletal systems. In particular, we highlight similarities and differences between human and rodents in terms of the specific roles of IP and EP1-4 receptors and their downstream signaling pathways, functions, and activities for each biologic system. We also highlight the potential novel therapeutic benefit of targeting IP and EP1-4 receptors in several diseases based on the scientific advances, animal models, and human studies. SIGNIFICANCE STATEMENT: In this review, we present an update of the pathophysiologic role of the prostacyclin receptor, prostaglandin E2 receptor (EP) 1, EP2, EP3, and EP4 receptors when activated by the two main prostaglandins, namely prostacyclin and prostaglandin E2, produced during inflammatory conditions in human and rodents. In addition, this comparison of the published results in each tissue and/or pathology should facilitate the choice of the most appropriate model for the future studies.

Drug delivery options and therapeutic advances in the management of erectile dysfunction

INTRODUCTION

Erectile dysfunction (ED) is defined as the inability to achieve or maintain an erection sufficient for satisfactory sexual performance. It is estimated that 20-30% of adult men will have at least one episode of ED during their lifetime and the prevalence increases with age. ED is known to have significant negative psychological implications for men, resulting in impaired functional status and a greater prevalence of anxiety and depression.

AREAS COVERED

Medications for the treatment of erectile dysfunction largely revolve around oral, injection, and topical therapies. Though all three modalities are widely used, each delivery option has its own advantages and specific indications. Likewise, there are several new developing treatments for ED that may change the landscape of treatment. The goal of this review is to summarize contemporary drug delivery options used in the treatment of ED and highlight future promising pharmacological developments.

EXPERT OPINION

There are a myriad of new developments on the horizon including new PDE5Is and drug targets, nanotechnology enhancements, stem cell and gene therapy, shockwave therapy, and platelet-rich plasma injections. These are all promising new methods to not only treat ED but also to address the pathology and prevent or eliminate further damage.

Human health benefits of very-long-chain polyunsaturated fatty acids from microalgae

Microalgae are single-cell, photosynthetic organisms whose biodiversity places them at the forefront of biological producers of high-value molecules including lipids and pigments. Some of these organisms particular are capable of synthesizing n-3 very long chain polyunsaturated fatty acids (VLC-PUFAs), known to have beneficial effects on human health. Indeed, VLC-PUFAs are the precursors of many signaling molecules in humans involved in the complexities of inflammatory processes. This mini-review provides an inventory of knowledge on the synthesis of VLC-PUFAs in microalgae and on the diversity of signaling molecules (prostanoids, leukotrienes, SPMs, EFOX, isoprostanoids) that arise in humans from VLC-PUFAs.

Druggable Prostanoid Pathway

Prostanoids (prostaglandins, prostacyclin and thromboxane) belong to the oxylipin family of biologically active lipids generated from arachidonic acid (AA). Protanoids control numerous physiological and pathological processes. Cyclooxygenase (COX) is a rate-limiting enzyme involved in the conversion of AA into prostanoids. There are two COX isozymes: the constitutive COX-1 and the inducible COX-2. COX-1 and COX-2 have similar structures, catalytic activities, and subcellular localizations but differ in patterns of expression and biological functions. Non-selective COX-1/2 or traditional, non-steroidal anti-inflammatory drugs (tNSAIDs) target both COX isoforms and are widely used to relieve pain, fever and inflammation. However, the use of NSAIDs is associated with various side effects, particularly in the gastrointestinal tract. NSAIDs selective for COX-2 inhibition (coxibs) were purposefully designed to spare gastrointestinal toxicity, but predisposed patients to increased cardiovascular risks. These health complications from NSAIDs prompted interest in the downstream effectors of the COX enzymes as novel drug targets. This chapter describes various safety issues with tNSAIDs and coxibs, and discusses the current development of novel classes of drugs targeting the prostanoid pathway, including nitrogen oxide- and hydrogen sulfide-releasing NSAIDs, inhibitors of prostanoid synthases, dual inhibitors, and prostanoid receptor agonists and antagonists.

Sildenafil corrects the increased contractility of rat detrusor muscle induced by alprostadil in vitro

BACKGROUND

Sildenafil (PDE5-inhibitor) and alprostadil (PGE₁) are used in combination clinically for the management of some cases of erectile dysfunction. Despite the roles of prostaglandins (PG) and nitric oxide (NO) pathways in contractility of bladder smooth muscle are frequently studied, the effect of sildenafil/alprostadil combination and the crosstalk between NO/cGMP and PG pathways on bladder activity is not documented.

METHODS

Organ-bath experiments were performed using isolated rat detrusor muscle. Direct and neurogenic contractions were induced using ACh and electric stimulation (EFS, 4Hz, 80V, 1ms), respectively. The contractile responses in absence and presence of the tested drugs at different concentrations were compared. Results are expressed as mean ± SEM (n = 5-7).

RESULTS

Alprostadil (0.01-10 μM) concentration-dependently potentiated ACh (100μM)- and EFS (4 Hz)- induced contraction. Maximum potentiation of ACh-contraction in presence of alprostadil was 40 ± 5%. Sildenafil potentiated ACh-induced contraction at low concentrations (0.01-1 μM), but inhibited it at higher ones (10-100 μM). IBMX (non-selective PDE-inhibitor, 0.01-100μM) and SNP (NO-donor, 1nM-1 mM) produced the same biphasic pattern. The potentiatory phase of sildenafil was inhibited by atropine (0.1μM), L-NAME (non-selective NOS-inhibitor, 100μM), N-PLA (nNOS-inhibitor, 30μM) or MB (nonselective GC-inhibitor, 10μM). In presence of sildenafil (0.1μM), the concentration-response curve of alprostadil (0.01-10μM) on both ACh and EFS-induced contraction was clearly shifted downward.

CONCLUSIONS

A crosstalk between PGE₁ and NO/cGMP pathways may exist. At low concentrations only, the effect of sildenafil on bladder contractility is dependent on NO/cGMP. cGMP intracellularly-elevated by sildenafil, may inhibit the activity of PLC and hence the cascade of EP₁-receptors, thus masking the hyperactivity of bladder caused by alprostadil, which adds to the advantages of this combination.

The intra-meatal application of alprostadil cream (Vitaros®) improves drug efficacy and patient's satisfaction: results from a randomized, two-administration route, cross-over clinical trial

To investigate the efficacy, tolerability, and patient's preference of alprostadil cream for topical use administered within the urethral meatus versus the standard administration route, in erectile dysfunction (ED) treatment. Seventy-one patients (mean age 59.7 ± 9.0 years) affected by ED were analyzed in this multicenter, randomized, two-administration routes, cross-over trial. All patients received a single dose of alprostadil cream applying the dispenser to the tip of the penis (without contacting the urethral meatus) (Standard administration route or ST.AR) alternating with a single dose of alprostadil cream applying the dispenser within the urethral meatus (New administration route or NEW.AR) separated by a one-week washout period, according to randomization. The primary objective of the study was to evaluate the change in International Index of Erectile Function (IIEF-5) total score from baseline to the control visit by comparing the ST.AR and NEW.AR. Secondary objectives of the study were to compare the different methods of administration by evaluating the change in the Sexual Encounter Profile (SEP-2 and SEP-3) questionnaire score and the Patient Reported Outcomes (PROs) by scoring the Patient Self-Assessment of Erection (PSAE) questionnaire. The treatment safety profile was assessed by analysis of adverse events (AEs). Based on the study findings it is evident that the NEW.AR is more efficacious than the ST.AR in improving IIEF-5 and SEP scores from baseline to control visit (IIEF-5: +3.8 vs +6.3; p < 0.001; positive response to SEP-2: 10 vs 27; p = 0.002) and in terms of PSAE (a significant improvement from the baseline in 31% of patients; p < 0.001). As regards the safety profile, no difference in terms of local and systemic side effects was found.

A panoramic view of medicinal plants traditionally applied for impotence and erectile dysfunction in Persian medicine

Erectile dysfunction (ED) and impotence are common male sexual problems, and they are highly prevalent in male adults with a history of hypertension or diabetes mellitus. This review aims to bring together the standpoints of the early Persian physicians on these disorders and to identify the respective medication in comparison with conventional contemporary medicine. The main medical and pharmaceutical manuscripts of traditional Persian medicine (TPM) are from 9th-18th century AD. Besides the medieval findings, the current knowledge on ED and impotence, and the related effects of the cited medicinal herbs were studied. In the medieval and traditional literature, male potency is called bāh. According to the TPM approaches, the first step in the mitigation of impotence focuses on the treatment of the main body organs including the heart, brain, and liver. The TPM approaches for diagnosis and treatment include the evaluation of the quality of semen, sexual habit, and quality of urine. The treatment strategies in TPM involve lifestyle modification and prescription of natural medicaments. Many medicinal herbs have been traditionally used for the mitigation of impotency. There could be numerous possibilities for bringing out new natural medicaments with aphrodisiac effects supported by the early medical literature.

Non-invasive Management Options for Erectile Dysfunction When a Phosphodiesterase Type 5 Inhibitor Fails

Phosphodiesterase type 5 inhibitors (PDE5Is) are the drug of choice for medical management of erectile dysfunction (ED). On-demand PDE5Is have an overall efficacy of 60-70% for ED; 30-35% of patients fail to respond to a PDE5I, and 30-50% of non-responders can be salvaged with detailed counseling on proper use and physician follow-up to ensure that the patient has been prescribed an appropriate and full PDE5I clinical trial. True non-responders may be offered intracavernosal injections of erectogenic drugs, intraurethral alprostadil, or surgical insertion of a penile prosthesis. Such options are not discreet and are associated with more adverse effects than PDE5Is. Thus patients may request additional non-invasive medical management options. This review describes published literature on patients who failed to respond to an on-demand PDE5I regimen and were treated with a non-invasive PDEI-based regimen, including switching from one PDE5I to another; increasing the dose of PDE5I above the labeled dosage range; using two PDE5Is concurrently; using a daily PDE5I regimen; or combining a PDE5I with a testosterone supplement, α-adrenergic antagonist, intraurethral or intracavernosal alprostadil, vacuum erection device, or low-intensity shock wave therapy. The limitations of published clinical trials do not allow for sufficient evidence to recommend one option over another. Therefore, in PDE5I-refractory patients, the choice of a specific next step should be individualized based on the preference of the patient and his sexual partner, the advantages and disadvantages of the various options, the concurrent medical illnesses and medications of the patient, and the patient's response to treatment.

Combination therapy for erectile dysfunction involving a PDE5 inhibitor and alprostadil

The phosphodiesterase-5 inhibitors (PDE5Is) are the first-line treatment option for men with erectile dysfunction (ED), with alprostadil considered a second-line choice. Consideration has to be given to patients who fail these treatments and what their options are. This review evaluates the data on the combination of a PDE5I with alprostadil in patients who have previously failed therapy with either drug. A PubMed search was conducted and identified nine publications relating to combination treatment with alprostadil as intracavernosal, intraurethral or topical application. The results indicate that with all three formulations the combination therapy resulted in an improved outcome compared with either of the drugs as monotherapy. This was demonstrated by the increased total International Index of Erectile Function (IIEF) scores as well as IIEF erectile function domain scores. This finding was also valid for patients with post-prostatectomy ED. The associated side effects of the combined treatment did not result in treatment discontinuation. These findings suggest that combination therapy with a PDE5I and alprostadil might be considered a treatment option in patients who have previously had a poor response to either drug.

Erectile Dysfunction in Systemic Sclerosis

Erectile dysfunction (ED) is a major issue in systemic sclerosis (SSc) as it is observed in around 80 to 90 % of men with this connective tissue disease. ED greatly impacts the quality of life and should be actively addressed as a common complication. Whereas ED in the general population is usually associated with risk factors for atherosclerosis as well as cardiovascular disease, the main aetiology of ED in SSc is microangiopathic. In SSc, the blood flow is reduced in the small penile arteries due to corporal fibrosis and myointimal proliferation. There are no data on the prevention of ED in SSc. On-demand phosphodiesterase-5 inhibitors have little effect in improving erectile function, but daily or alternate day regimens of long-acting phosphodiesterase-5 inhibitors provide a measurable, although often limited, benefit. When intracavernous prostaglandin E1 injections are also ineffective, the implantation of a penile prosthesis should be considered as an option.

Prognostic factors for profound sudden idiopathic sensorineural hearing loss: a multicenter retrospective study

The aim of this study was to assess the outcomes of various treatment modalities for profound idiopathic sudden sensorineural hearing loss (ISSNHL) and confirm the prognostic factors. In total, 191 patients were enrolled after a thorough medical chart review of patients diagnosed with unilateral, profound ISSNHL (≥90 dB). Epidemiological profiles, therapeutic regimens, and the results of pure tone audiometry tests were recorded for all patients. Final recovery was assessed according to Siegel's criteria and by comparing the final hearing level of the affected ear with that of the unaffected ear. The mean follow-up duration and the final hearing level were 75 ± 54 days and 77 ± 24 dB, respectively. None of the evaluated prognostic factors were significantly associated with complete recovery (<25 dB). However, improved hearing in both ears, the absence of dizziness, the use of lipo-prostaglandin E1 (lipo-PGE1), and the use of plasma volume expanders were independently associated with a final hearing level of up to 45 dB (p < 0.05). Steroid dose reduction, worse initial hearing, and non-use of lipo-PGE1 increased the possibility of no recovery. Although the efficacy of oral steroid treatment for profound ISSNHL has been questioned, steroid dose reduction was significantly associated with no recovery. Therefore, adequate oral corticosteroid doses should be considered in the absence of contraindications. In addition, the use of lipo-PGE1 and/or a plasma volume expander seems preferable for better recovery, and their use for the management of profound ISSNHL should be considered.

Clinical use of alprostadil topical cream in patients with erectile dysfunction: a review

Erectile dysfunction (ED) is a common and debilitating disorder seen in over 50% of men older than 70 years. Oral phosphodiesterase type 5 (PDE5) inhibitors are the mainstay of treatment for ED, but cannot be used by a significant subset of patients due to systemic side effects and drug-drug interactions. Second-line therapy may include intracavernosal therapies, but are associated with poor compliance due to their invasive nature. Alprostadil has a mechanism of action different from that of PDE5 inhibitors. Clinical trials have shown topical alprostadil cream to be effective, increasing the erectile function (EF) score of the International Index of EF by up to 13 points from baseline. It has also proven to be safe and well tolerated, with mild-to-moderate and transient treatment-related adverse events that are generally localized to the application site. Topical alprostadil cream is a safe and effective second-line therapy for ED, indicated for those who cannot tolerate, or are not satisfied with, oral PDE5 inhibitor therapy.

Molecular Interactions and Implications of Aldose Reductase Inhibition by PGA1 and Clinically Used Prostaglandins

Aldose reductase (AKR1B1) is a critical drug target because of its involvement in diabetic complications, inflammation, and tumorigenesis. However, to date, development of clinically useful inhibitors has been largely unsuccessful. Cyclopentenone prostaglandins (cyPGs) are reactive lipid mediators that bind covalently to proteins and exert anti-inflammatory and antiproliferative effects in numerous settings. By pursuing targets for modification by cyPGs we have found that the cyPG PGA1 binds to and inactivates AKR1B1. A PGA1-AKR1B1 adduct was observed, both by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and by SDS-PAGE using biotinylated PGA1 (PGA1-B). Insight into the molecular interactions between AKR1B1 and PGA1 was advanced by molecular modeling. This anticipated the addition of PGA1 to active site Cys298 and the potential reversibility of the adduct, which was supported experimentally. Indeed, loss of biotin label from the AKR1B1-PGA1-B adduct was favored by glutathione, indicating a retro-Michael reaction, which unveils new implications of cyPG-protein interaction. PGA1 elicited only marginal inhibition of aldehyde reductase (AKR1A1), considered responsible for the severe adverse effects of many AKR1B1 inhibitors. Interestingly, other prostaglandins (PGs) inhibited the enzyme, including non-electrophilic PGE1 and PGE2, currently used in clinical practice. Moreover, both PGA1 and PGE1 reduced the formation of sorbitol in an ex-vivo model of diabetic cataract to an extent comparable to that attained by the known AKR inhibitor epalrestat. Taken together, these results highlight the role of PGs as AKR1B1 inhibitors and the interest in PG-related molecules as leads for the development of novel pharmacological tools.

Identification of Drugs that Regulate Dermal Stem Cells and Enhance Skin Repair

Here, we asked whether we could identify pharmacological agents that enhance endogenous stem cell function to promote skin repair, focusing on skin-derived precursors (SKPs), a dermal precursor cell population. Libraries of compounds already used in humans were screened for their ability to enhance the self-renewal of human and rodent SKPs. We identified and validated five such compounds, and showed that two of them, alprostadil and trimebutine maleate, enhanced the repair of full thickness skin wounds in middle-aged mice. Moreover, SKPs isolated from drug-treated skin displayed long-term increases in self-renewal when cultured in basal growth medium without drugs. Both alprostadil and trimebutine maleate likely mediated increases in SKP self-renewal by moderate hyperactivation of the MEK-ERK pathway. These findings identify candidates for potential clinical use in human skin repair, and provide support for the idea that pharmacological activation of endogenous tissue precursors represents a viable therapeutic strategy.

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Small-molecule screens identify compounds that enhance SKP self-renewal

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Alprostadil and trimebutine maleate both increase SKP self-renewal

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Both compounds likely act by promoting activation of the MEK-ERK pathway

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Both compounds activated dermal precursors in vivo to enhance wound healing

Erectile dysfunction and its management in patients with diabetes mellitus

Diabetes can be described as a syndrome of multiple closely related conditions induced by a chronic state of hyperglycaemia resulting from defective insulin secretion, insulin action or both. Chronic complications associated with diabetes (including neuropathy, vascular disease, nephropathy and retinopathy) are common, and of these, erectile dysfunction (ED) deserves special attention. ED and its correlation with cardiovascular disease require careful evaluation and appropriate treatment. PDE5 inhibitors (PDE5is) are an important tool for the treatment of ED, with new drugs coming onto the market since the late 90s. This review offers an overview of PDE5is and their use in treating ED in diabetes. We underline the differences between different types of PDE5i, focusing on available doses, duration of action, T ½, side effects and selectivity profiles in relation to patients with diabetes. We also discuss the link between diabetes and ED in presence of various associated cofactors (obesity, hypertension and its pharmacological treatments, atherosclerosis, hyperhomocysteinaemia, neuropathy, nephropathy, hypogonadism and depression). Finally a number of past and ongoing clinical trials on the use of PDE5is in patients with diabetes are presented to offer an overview of the appropriate treatment of ED in this condition.

The clinical relevance of sexual dysfunction in systemic sclerosis

Systemic sclerosis is a chronic multi-organ autoimmune disease, leading to important clinical and psychological implications. Among organ complications, sexual dysfunction is a major issue for both male and female gender, with high prevalence and great impact on quality of life, although frequently not addressed by both clinicians and patients. While erectile dysfunction is the most common cause of sexual problems in males, genital tract and general physical changes are major contributors to sexual impairment in females. This review presents current state of the art on this topic, discussing published data on presentation, evaluation and therapeutic options.

Emerging drugs for the treatment of erectile dysfunction

INTRODUCTION

Erectile dysfunction adversely affects the lives of millions of men, and is the most commonly treated sexual disorder today. The erectile process has been extensively investigated, with major advances made in elucidating many of the complex molecular pathways involved. These advances have allowed researchers to design and study drug formulations that target various aspects of this complex process. The initial culmination of this research was the introduction of phosphodiesterase 5-inhibitors. While effective in many patients, they are not satisfactory for all afflicted men. As a result, researchers are developing novel drugs that target different molecular pathways.

AREAS COVERED

The paper will review these pathways, and the potential agents that target them. More specifically, first dopaminergic and melanocortin receptor agonists that act centrally will be covered. Then, the paper will examine the "second-generation" phosphodiesterase 5-inhibitors, soluble guanylate cyclases, rho-kinase inhibitors, and maxi-k channel activators that act peripherally.

EXPERT OPINION

Most of these novel drugs have yet to reach Phase III studies. However, it is likely that in years to come, patients will be selectively treated with these novel agents as a monotherapy or in combination with others acting in a synergistic manner.

Clinical Efficacy and Safety of Vitaros©/Virirec© (Alprostadil Cream) for the Treatment of Erectile Dysfunction

Erectile dysfunction (ED) is a very common disorder with a deep impact on patients and their partners. Several options are now available for treating ED; oral pharmacotherapy with phosphodiesterase-5 (PDE5) inhibitors currently represents the first-line option for many ED patients. Vitaros©/Virirec© is new topical, non-invasive treatment for ED that offers the combination of an active drug (alprostadil, a synthetic PGE1) with a skin enhancer that improves its local absorption directly at the site of action. Vitaros©/Virirec© has a favorable pharmacodynamic profile and is poorly absorbed in systemic circulation. This makes it suitable in any circumstances and results in a reduced risk of adverse events (AEs), being systemic AEs reported in only 3% of the treated population. Its clinical efficacy has been demonstrated in both phase II and III trials, showing a global efficacy up to 83% with the 300 μg dose in patients with severe ED significantly better than placebo. Its fast onset of action together with its favorable toxicity profile and lack of interactions with other drugs makes Vitaros©/Virirec© a first-line therapeutic option for patients with ED, particularly for individuals who are reluctant to take systemic treatments or with AEs. It may also have an important role in patients not responding to PDE5 inhibitors, particularly those with ED after radical prostatectomy.

Treatment strategies for diabetic patients suffering from erectile dysfunction: an update

INTRODUCTION

Erectile dysfunction (ED) is one of the most common complications of diabetes. The complex pathophysiology of this disease makes it difficult to create clinical treatments tailored specifically for diabetic patients.

AREAS COVERED

This article will provide an update of both medical and surgical treatment approaches for diabetic ED, as well as discuss established treatments that are the cornerstone of this field.

EXPERT OPINION

Currently, PDE type 5 inhibitors represent the first-line treatment for all patients with ED. In the interim since this article's first publication several new PDE5 inhibitors have come to market. Several others that were previously on the market are now available for daily dosing. Analysis of both testosterone level and hemoglobin A1c is an essential part of treatment. Intracavernosal injections and vacuum constriction devices remain safe, and are highly effective treatment options. The implantable penile prosthesis remains a safe, and definitive treatment modality for those patients with refractory ED. Over the coming years as the understanding of the underlying causes of diabetic ED continues, the development of new, noninvasive, but effective medical treatments will lead to even more options for the treatment of this difficult disease.