Treating Erectile Dysfunction and Central Neurological Diseases with Oral Phosphodiesterase Type 5 Inhibitors. Review of the Literature

Emerging phosphodiesterase inhibitors for treatment of neurodegenerative diseases

Neurodegenerative diseases (NDs) cause progressive loss of neuron structure and ultimately lead to neuronal cell death. Since the available drugs show only limited symptomatic relief, NDs are currently considered as incurable. This review will illustrate the principal roles of the signaling systems of cyclic adenosine and guanosine 3',5'-monophosphates (cAMP and cGMP) in the neuronal functions, and summarize expression/activity changes of the associated enzymes in the ND patients, including cyclases, protein kinases, and phosphodiesterases (PDEs). As the sole enzymes hydrolyzing cAMP and cGMP, PDEs are logical targets for modification of neurodegeneration. We will focus on PDE inhibitors and their potentials as disease-modifying therapeutics for the treatment of Alzheimer's disease, Parkinson's disease, and Huntington's disease. For the overlapped but distinct contributions of cAMP and cGMP to NDs, we hypothesize that dual PDE inhibitors, which simultaneously regulate both cAMP and cGMP signaling pathways, may have complementary and synergistic effects on modifying neurodegeneration and thus represent a new direction on the discovery of ND drugs.

Summary of the 2024 Update of the European Association of Urology Guidelines on Neurourology

BACKGROUND AND OBJECTIVE

Most patients with neurourological disorders require lifelong medical care. The European Association of Urology (EAU) regularly updates guidelines for diagnosis and treatment of these patients. The objective of this review is to provide a summary of the 2024 updated EAU guidelines on neurourology.

METHODS

A structured literature review covering the timeframe 2021-2023 was conducted for the guideline update. A level of evidence and a strength rating were assigned for each recommendation on the basis of the literature data.

KEY FINDINGS AND LIMITATIONS

Neurological conditions significantly affect urinary, sexual, and bowel function, and lifelong management is required for neurourological patients to maintain their quality of life and prevent urinary tract deterioration. Early diagnosis and effective treatment are key, and comprehensive clinical assessments, including urodynamics, are crucial. Management should be customised to individual needs and should involve a multidisciplinary approach and address sexuality and fertility. Lifelong monitoring and follow-up highlight the importance of continuous care for neurourological patients.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The 2024 EAU guidelines on neurourology provide an up-to-date overview of available evidence on diagnosis, treatment, and follow-up for neurourological patients.

PATIENT SUMMARY

Neurological disorders very frequently affect the lower urinary tract and sexual and bowel function and patients need lifelong management. We summarise the updated European Association of Urology guidelines on neurourology to provide patients and caregivers with the latest insights for optimal health care support.

Medical, surgical, and physical treatments for Parkinson's disease

Although dopamine replacement therapy remains a core component of Parkinson's disease treatment, the onset of motor fluctuations and dyskinetic movements might require a range of medical and surgical approaches from a multidisciplinary team, and important new approaches in the delivery of dopamine replacement are becoming available. The more challenging, wide range of non-motor symptoms can also have a major impact on the quality of life of a patient with Parkinson's disease, and requires careful multidisciplinary management using evidence-based knowledge, as well as appropriately tailored strategies according to the individual patient's needs. Disease-modifying therapies are urgently needed to prevent the development of the most disabling refractory symptoms, including gait and balance difficulties, cognitive impairment and dementia, and speech and swallowing impairments. In the third paper in this Series, we present the latest evidence supporting the optimal treatment of Parkinson's disease, and describe an expert approach to many aspects of treatment choice where an evidence base is insufficient.

Classification and management of sexual dysfunctions in multiple sclerosis patients: A review of current literature

Multiple sclerosis (MS) is the most frequent neurological disease in young adults, with the greatest incidence between age of 30 and 35 years. Sexual dysfunctions (SDs) are frequent, but are often underestimated in patients with MS, and can have a significantly high impact on patient's quality of life. Aim of this review is to summarize sexual dysfunctions in male and female MS patients and to illustrate current and emerging therapeutic options for treatment.

The Italian Society of Andrology and Sexual Medicine (SIAMS), along with ten other Italian Scientific Societies, guidelines on the diagnosis and management of erectile dysfunction

PURPOSE

Erectile dysfunction (ED) is one of the most prevalent male sexual dysfunctions. ED has been in the past mistakenly considered a purely psycho-sexological symptom by patients and doctors. However, an ever-growing body of evidence supporting the role of several organic factors in the pathophysiological mechanisms underlying ED has been recognized.

METHODS

The Italian Society of Andrology and Sexual Medicine (SIAMS) commissioned an expert task force involving several other National Societies to provide an updated guideline on the diagnosis and management of ED. Derived recommendations were based on the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system.

RESULTS

Several evidence-based statements were released providing the necessary up-to-date guidance in the context of ED with organic and psychosexual comorbidities. Many of them were related to incorrect lifestyle habits suggesting how to associate pharmacotherapies and counseling, in a couple-centered approach. Having the oral therapy with phosphodiesterase type 5 inhibitors as the gold standard along with several other medical and surgical therapies, new therapeutic or controversial options were also discussed.

CONCLUSIONS

These are the first guidelines based on a multidisciplinary approach that involves the most important Societies related to the field of sexual medicine. This fruitful discussion allowed for a general agreement on several recommendations and suggestions to be reached, which can support all stakeholders in improving couple sexual satisfaction and overall general health.

Nrf2 and NF-қB interplay in tamoxifen-induced hepatic toxicity: A promising therapeutic approach of sildenafil and low-dose γ radiation

Tamoxifen-induced hepatotoxicity is an inevitable side effect during breast cancer treatment. Low-dose gamma irradiation (IRR) shows many beneficial effects by stimulating various biological processes. This study evaluates the possible effect of sildenafil and low-dose gamma radiation on liver damages as new treatment strategies. Group I (control), group II: (tamoxifen), group III: (tamoxifen + Sildenafil), group IV: (tamoxifen+ irradiation) and group V: (tamoxifen +Sildenafil + irradiation). Rats were sacrificed after 5 h from tamoxifen injection. Results showed that tamoxifen caused elevation in serum AST, ALT and ALP as well hepatic ROS, iNOS, MDA, Keap-1 and NF-Kb, in addition to diminution in hepatic Nrf2 and HO-1. Exposure to low-dose gamma radiation and sildenafil amended the alterations in the measured parameters in serum and tissue. Moreover, all results were confirmed by histopathological examination. In conclusion, sildenafil and low-dose gamma radiation can mitigate the toxicity induced by tamoxifen in liver tissues. Hence, this treatment could be further evaluated as a new approach for alleviating various liver disorders.

Autonomic nervous system disorders in multiple sclerosis

Multiple sclerosis (MS) is a chronic progressive demyelinating disease of the central nervous system (CNS), which also affects the autonomic nervous system (ANS). Manifestations of MS in the ANS include urological, sexual, gastrointestinal, cardiovascular, and thermoregulatory disorders as well as increased fatigue. These problems are common yet are often underestimated due to the non-specificity of the symptoms and the limited evaluation of the ANS in the usual clinical practice. Most of these symptoms seem to be related to localized lesions in the CNS. However, the mechanisms by which these disorders are caused in MS have not been fully investigated, thus preventing any focused etiological treatment. The most common disorders of the ANS in MS represent a challenge for clinicians due to the variability of the clinical picture and our minimal data on their diagnosis and treatment. Early diagnosis and initiation of individualized treatment regimens, often in need of multiple approaches, seem to yield the best results in managing ANS dysfunction in MS patients.

Correlation between gut microbiota diversity and psychogenic erectile dysfunction

Background

To analyze the distribution of gut microbiota in erectile dysfunction (ED) patients and explore the relationship between the diversity of gut microbiota and psychogenic ED.

Methods

Stool specimen were collected from 30 patients with ED and 30 healthy persons (healthy donors, HDs) and analyzed Paired end (PE) 300 sequencing on V3-V4 region sequences of bacterial 16S rRNA gene by using Illumina's Miseq platform, whereby sequencing results were analyzed to assess differences in species composition and diversity. The analysis comprised five modules: sequencing data quality control, operational taxonomic units (OTU) species clustering and annotation, alpha diversity, beta diversity and the use of t-tests and analysis of linear discriminant analysis effect size (LEfSe) differences.

Results

The International Index of Erectile Function (IIEF-5) score ranged between 8 and 21. The scores of ED patients were ≥11 and ≤20, and the mean value was 15.67±2.94. The flora diversity in the group of ED patients was significantly different from that of HDs (P<0.01), with the ED group having low bacterial diversity. There were no significant differences in the genus level between the ED and HD group, and abundant bacteria (TOP10) and core flora (90%). Comparison of total flora (the abundance >1%) display, Alloprevotella genera showed differences, whereby Alloprevotella was only be identified in the HD group. Erectile dysfunction and HD showed good separation and clustering respectively in principal component analysis, showing significant differences in two kinds of microflora. T-tests showed that six species were significantly different, and that in the ED group, streptococci and Subdoligranulum were significantly increasing, and Prevotella sp.9, Blautia, Lachnospiraceae NK4A136 groups and Roseburia were significantly lower. Analysis using LEfSe analysis revealed 24 species were significantly different between ED and HD groups.

Conclusions

When gene sequencing was performed of ED and HD specimens, the microbial community structure and diversity showed significant differences, suggesting that ED specimen had lower gut microbiota diversity.

Molecular Action of Herbal Medicine in Physiology of Erection and its Dysfunction

Erection is a physiological process that involves vascular, hormonal, and nervous factors. Erectile dysfunction is one of the male sexual problems that occur globally and is reported to affect men's quality of life. Herbal plants have been widely used for disease treatment, including the problem of erectile dysfunction. This paper aims to review the molecular potential of various plants in the physiology of erection and to treat erectile dysfunction. The literature search was carried out through the Pubmed and Google Scholar databases regarding the molecular mechanisms of herbal plants and their potential involvement in the physiology of erection and overcoming erectile dysfunction. This paper focuses on six herbal plants: Panax ginseng, Ginkgo biloba, Epimedium, Black pepper, Tribulus terrestris, and Eurycoma longifolia. The six herbal plants have involvement in the erection process and have molecular potential in the treatment of erectile problems

Neurogenic Erectile Dysfunction. Where Do We Stand?

Erectile Dysfunction (ED) is the persistent inability to attain and maintain an erection sufficient to permit satisfactory sexual performance, causing tremendous effects on both patients and their partners. The pathophysiology of ED remains a labyrinth. The underlying mechanisms of ED may be vasculogenic, neurogenic, anatomical, hormonal, drug-induced and/or psychogenic. Neurogenic ED consists of a large cohort of ED, accounting for about 10% to 19% of all cases. Its diversity does not allow an in-depth clarification of all the underlying mechanisms nor a “one size fits all” therapeutical approach. In this review, we focus on neurogenic causes of ED, trying to elucidate the mechanisms that lie beneath it and how we manage these patients.

Managing Urological Disorders in Multiple Sclerosis Patients: A Review of Available and Emerging Therapies

Multiple sclerosis (MS) is a progressive neurological autoimmune disease with a diverse range of urological symptomatology, and most MS patients experience 1 or more moderate to severe urinary symptoms, as well as bladder and/or sexual disorders. Urologists play the director's role in evaluating and treating these patients. Therefore, identifying the proper evaluation tools and the most suitable therapeutic options for specific patients requires a thorough understanding of this disease process.

Endothelial progenitor cells promote viability and nerve regenerative ability of mesenchymal stem cells through PDGF-BB/PDGFR-β signaling

Denervation-induced erectile dysfunction (ED) is a prevailing health problem. Our previous study revealed that endothelial progenitor cells (EPCs) promoted the effect of mesenchymal stem cells (MSCs) on restoration of denervation-induced ED in rats. However, underling mechanisms are still largely elusive. In this study, EPCs and MSCs were co-cultured and resorted to co-EPCs and co-MSCs. EPCs-derived paracrine factors containing PDGF-BB (platelet-derived growth factor) were detected, and MSCs were pre-treated with PDGF-BB, while co-MSCs were pre-treated with PDGFR inhibitor AG1296. Either viability or nerve regenerative ability of MSCs was evaluated. In addition, inhibition of either PI3K/Akt or MEK/Erk pathway was performed to evaluate the role of PI3K/Akt and MEK/Erk pathway in PDGF-BB-induced viability of MSCs. The results revealed that PDGF-BB significantly increased the proportion of PDGFR-β⁺ MSCs, and promoted both in-vitro and in-vivo viability, as well as nerve regenerative capacity and erectile function restoration of MSCs in rats. Inhibition of PI3K/Akt, MEK/Erk pathway or mTOR led to decrease of PDGF-BB/PDGFR-β induced viability of MSCs. To our knowledge, our study first demonstrates that EPCs promote viability and potential nerve regenerative ability of MSCs through PDGF-BB/PDGFR-β signaling and its downstream PI3K/Akt and MEK/Erk pathways. mTOR acts as a co-mediator in PI3K/Akt and MEK/Erk pathways.

Phosphodiesterase inhibitors say NO to Alzheimer's disease

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

The effect of sildenafil on rats with adenine-Induced chronic kidney disease

The erectile dysfunction drug sildenafil has cardiopulmonary protective actions, and a nephroprotective action in cisplatin and ischemia-reperfusion-induced acute kidney injury. Here, we assessed its possible ameliorative action in a model of chronic kidney disease (CKD) using adenine feeding. Eight groups of rats were treated with saline (controls), adenine (0.25% w/w in feed daily for 5 weeks), and oral sildenafil (0.1, 0.5 or 2.5 mg/kg), either alone, or concomitantly with adenine. Urine was collected 24 h after the end of the treatments from all rats and blood pressure measured, followed by collection of blood and kidneys for the measurement of several functional, biochemical and histopathological parameters. Adenine treatment reduced body weight, creatinine renal clearance, and increased water intake and urine output, as well as the plasma concentrations of urea and creatinine, neutrophil gelatinase-associated lipocalin, and N-acetyl-β-D-glucosaminidase activity, and albumin in urine. Adenine also increased the concentrations of the uremic toxins indoxyl sulfate, uric acid and phosphate, and a number of proteins and inflammatory cytokines, and decreased that of several anti - oxidant indices. Renal histopathological markers of damage (inflammation and fibrosis) were significantly increased by adenine. Sildenafil, given simultaneously with adenine, induced a dose - dependent improvements in most of the above parameters, suggesting its possible use as adjunct treatment for CKD in humans.

Management of Erectile Dysfunction and Infertility in the Male Spinal Cord Injury Patient

PURPOSE OF REVIEW

Men with spinal cord injury (SCI) commonly suffer from erectile dysfunction and ejaculatory dysfunction. The literature regarding the causes and treatment of these two important problems was reviewed.

RECENT FINDINGS

Many of the erectile dysfunction treatments applied to able bodied individuals are also useful in the SCI population, although there are differences in the goals and results of treatment. Ejaculatory dysfunction can be treated with either penile vibratory stimulation or electroejaculation with high success rates. Pregnancies are possible, but poor quality sperm quality in male SCI patients leads to pregnancy rates lower than is observed in the able-bodied population. Although effective treatments are available for erectile and ejaculatory dysfunction in men with SCIs, many challenges remain in optimizing the treatment of these individuals.

Treating male sexual dysfunction after traumatic brain injury: Two case reports

BACKGROUND

Sexual dysfunction is common after traumatic brain injury (TBI) but evaluation of treatment interventions have been sparse.

OBJECTIVE

To report on the treatment of sexual dysfunction for two males with severe TBI.

METHODS AND RESULTS

Case one was treated for erectile dysfunction (ED). After a medical examination which found no underlying physiological problems, Sildenafil was prescribed. Scores on the Golombok Rust Inventory of Sexual Satisfaction Impotence subscale found that scores had improved from the dysfunction range at baseline to the functional range at 6 weeks follow-up. There was some reduction in this improvement at 3 months follow-up, maybe associated with a co-morbid deterioration of emotional state. Case two was treated for idiopathic delayed ejaculation (DE). A standard sex therapy intervention was employed that resulted in the resolution of the problem, documented on the Sex Behavior sub-scale of the Derogatis Inventory for Sexual Functioning-Self Report (comparing baseline to post intervention and follow-up scores).

CONCLUSIONS

The case reports show promise for the treatment of sexual dysfunction after severe TBI using standard medical and sex therapy treatments. In the future, controlled evaluations are required to demonstrate the efficacy of such interventions.

Reproductive Health of Men with Spinal Cord Injury

Most men with spinal cord injury (SCI) are infertile due to a combination of erectile dysfunction, ejaculatory dysfunction, and abnormal semen quality. This article addresses issues that should be considered when managing the reproductive health of men with SCI. The authors present recommendations based on their decades of experience in managing the reproductive health of more than 1,000 men with SCI. Men with SCI face obstacles when pursuing sexual activity and/or biologic fatherhood. Hypogonadism and premature symptoms of aging may interfere with sexual function. Erectile dysfunction is prevalent in the SCI population, and treatments for erectile dysfunction in the general population are also effective in the SCI population. Most men with SCI cannot ejaculate with sexual intercourse. The procedures of penile vibratory stimulation (PVS) and/or electroejaculation (EEJ) are effective in obtaining an ejaculate from 97% of men with SCI. The ejaculate often contains sufficient total motile sperm to consider the assisted conception procedures of intrauterine insemination or even intravaginal insemination at home. If PVS and/or EEJ fail, sperm may be retrieved surgically from the testis or epididymis. Surgical sperm retrieval typically yields enough motile sperm only for in vitro fertilization with intracytoplasmic sperm injection. The majority of new cases of SCI occur in young men at the peak of their reproductive health. With proper medical management, these men can expect to experience active sexual lives and biologic fatherhood, if these are their goals. Numerous tools are available to physicians for helping these patients reach their goals.

The Wonders of Phosphodiesterase-5 Inhibitors: A Majestic History

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

The treatment of erectile dysfunction in patients with neurogenic disease

Erectile dysfunction (ED) related to compromise of the nervous system is an increasingly common occurrence. This may be due to the multifactorial nature of ED, the myriad of disorders affecting the neurotransmission of erectogenic signals, and improved awareness and diagnosis of ED. Nevertheless, neurogenic ED remains poorly understood and characterized. Disease related factors such as depression, decreased physical and mental function, the burden of chronic illness, and loss of independence may preclude sexual intimacy and lead to ED as well. The amount of data regarding treatment options in subpopulations of differing neurologic disorders remains scarce except for men with spinal cord injury. The treatment options including phosphodiesterase inhibitors, intracavernosal or intraurethral vasoactive agents, vacuum erection devices (VED) and penile prosthetic implantation remain constant. This review discusses the options in specific neurologic conditions, and briefly provides insight into new and future developments that may reshape the management of neurogenic ED.

Efficacy and safety of phosphodieterase-5 inhibitors for treatment of erectile dysfunction secondary to spinal cord injury: a systemic review and meta-analysis

STUDY DESIGN

Systemic reviewObjective:We carried out a systematic review and meta-analysis to assess the efficacy and safety of phosphodieterase-5 (PDE5) inhibitors on erectile dysfunction (ED) secondary to spinal cord injury (SCI).

METHODS

A literature review was performed to identify all published randomized, double-blind, placebo-controlled trials of PDE5 inhibitors for treatment of ED secondary to SCI. The search included the following database: MEDLINE, EMBASE and the Cochrane Library. The outcomes and complications analyzed involved the Global Efficacy Question (GEQ), sexual encounter profile diary question 2 and 3 (SEP2 and SEP3) and adverse events. All statistical analysis was performed using Stata 12.0 software (Stata Corp., College Station, TX, USA).

RESULTS

Six publications were used in analysis, including six randomized controlled trials that compared PDE5 inhibitors with placebo. Compared with placebo, PDE5 inhibitors were associated with significant improvements in GEQ (OR 11.997, 95% CI 8.073-17.830, P<0.0001), SEP2 (RR 1.847, 95% CI 1.561-2.185, P<0.0001) and SEP3 (RR 2.738, 95% CI 2.084-3.598, P<0.0001). Despite significant greater incidences of some adverse events observed (headache: RR 3.717, 95% CI 2.309-5.982, P<0.0001; flushing: RR 9.281, 95% CI 2.858-30.147, P<0.0001; gastrointestinal discomfort: RR 9.064, 95% CI 2.116-38.827, P=0.003), most adverse events were mild to moderate and transient.

CONCLUSIONS

This systematic review and meta-analysis indicate that PDE5 inhibitors are effective and well tolerated to treat ED secondary to SCI compared with placebo, as measured by response to GEQ, SEP2, SEP3 and incidence of adverse events. PDE5 inhibitors could be considered as the first choice in the treatment of ED patients with SCI.

Summary of European Association of Urology (EAU) Guidelines on Neuro-Urology

CONTEXT

Most patients with neuro-urological disorders require life-long medical care. The European Association of Urology (EAU) regularly updates guidelines for the diagnosis and treatment of these patients.

OBJECTIVE

To provide a summary of the 2015 updated EAU Guidelines on Neuro-Urology.

EVIDENCE ACQUISITION

Structured literature searches in several databases were carried out to update the 2014 guidelines. Levels of evidence and grades of recommendation were assigned where possible.

EVIDENCE SYNTHESIS

Neurological disorders often cause urinary tract, sexual, and bowel dysfunction. Most neuro-urological patients need life-long care for optimal life expectancy and quality of life. Timely diagnosis and treatment are essential to prevent upper and lower urinary tract deterioration. Clinical assessment should be comprehensive and usually includes a urodynamic investigation. The neuro-urological management must be tailored to the needs of the individual patient and may require a multidisciplinary approach. Sexuality and fertility issues should not be ignored. Numerous conservative and noninvasive possibilities of management are available and should be considered before a surgical approach is chosen. Neuro-urological patients require life-long follow-up and particular attention has to be paid to this aspect of management.

CONCLUSIONS

The current EAU Guidelines on Neuro-Urology provide an up-to-date overview of the available evidence for adequate diagnosis, treatment, and follow-up of neuro-urological patients.

PATIENT SUMMARY

Patients with a neurological disorder often suffer from urinary tract, sexual, and bowel dysfunction and life-long care is usually necessary. The update of the EAU Guidelines on Neuro-Urology, summarized in this paper, enables caregivers to provide optimal support to neuro-urological patients. Conservative, noninvasive, or minimally invasive approaches are often possible.

Autonomic Dysregulation in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic, progressive central neurological disease characterized by inflammation and demyelination. In patients with MS, dysregulation of the autonomic nervous system may present with various clinical symptoms including sweating abnormalities, urinary dysfunction, orthostatic dysregulation, gastrointestinal symptoms, and sexual dysfunction. These autonomic disturbances reduce the quality of life of affected patients and constitute a clinical challenge to the physician due to variability of clinical presentation and inconsistent data on diagnosis and treatment. Early diagnosis and initiation of individualized interdisciplinary and multimodal strategies is beneficial in the management of autonomic dysfunction in MS. This review summarizes the current literature on the most prevalent aspects of autonomic dysfunction in MS and provides reference to underlying pathophysiological mechanisms as well as means of diagnosis and treatment.

Ciprofloxacin-Induced Antibacterial Activity Is Attenuated by Phosphodiesterase Inhibitors

Background

Ciprofloxacin is a commonly used antibiotic for urinary tract infection that interacts with bacterial topoisomerases leading to oxidative radicals generation and bacterial cell death. Phosphodiesterase inhibitors (PDEis), on the other hand, are commonly used drugs for the management of erectile dysfunction. The group includes agents such as sildenafil, vardenafil, and tadalafil.

Objectives

We investigated whether PDEi could interfere with the antibacterial activity of ciprofloxacin.

Methods

PDEis were tested in several reference bacteria, including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, Acinetobacter baumannii, Proteus mirabilis, and Klebsiella pneumoniae utilizing a standard disc diffusion method and measuring both zones of inhibition and MIC.

Results

Results from both assays indicated that ciprofloxacin demonstrates potent activity against the tested reference bacteria. Additionally, when bacteria were treated with a combination of ciprofloxacin and sildenafil, tadalafil, or vardenafil, the zones of the combination inhibition were significantly reduced, whereas the MIC values were significantly greater than those of ciprofloxacin alone for all tested bacterial strains. In an attempt to examine the mechanism by which PDEis interfere with the action of ciprofloxacin, we utilized the in vitro E coli DNA gyrase cleavage assay. The results showed that PDEi drugs had no effect on ciprofloxacin’s inhibition of E coli gyrase activity.

Conclusions

Pretreatment of various reference bacterial cells with PDEis largely inhibited the antibacterial activity of ciprofloxacin.

Evaluation of Sexual Function and Its Contributing Factors in Men With Spinal Cord Injury Using a Self-Administered Questionnaire

Sexual activity is an important aspect of life in patients with spinal cord injury (SCI), rated as one of the top priorities for recovery of function. This study was conducted to establish an understanding of the severity of erectile dysfunction (ED), a major component of male sexual activity, and its correlates in patients with SCI in our community. In a cross-sectional study, 37 male veterans with SCI admitted for regular follow-up at our center were recruited. Demographic and SCI-related descriptive information was gathered through a self-administered questionnaire. Sexual Health Inventory for Men was used to assess the presence and severity of ED. Euro Quality of Life questionnaire and General Health Questionnaire (GHQ-12) were also administered. The mean age of the participants was 45.7 ± 6.5 years with injury duration of 24.7 ± 6.2 years. Mean GHQ-12 score of 3.65 ± 3.38 and mean Sexual Health Inventory for Men score of 11.57 ± 5.28 were measured. All participants had ED, and 27% were suffering from severe ED. Sleep deprivation, worse GHQ-12 score, and hypertension were significantly associated with higher risk of much severe ED ( p < .05). In conclusion, ED is a common problem in veterans with SCI and is inversely associated with their general health status.

Icariin, a phosphodiesterase-5 inhibitor, improves learning and memory in APP/PS1 transgenic mice by stimulation of NO/cGMP signalling

Phosphodiesterase-5 (PDE5) inhibitors are predominantly used in the treatment of erectile dysfunction, and have been recently shown to have a potential therapeutic effect for the treatment of Alzheimer's disease (AD) through stimulation of nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signalling by elevating cGMP, which is a secondary messenger involved in processes of neuroplasticity. In the present study, the effects of a PDE5 inhibitor, icarrin (ICA), on learning and memory as well as the pathological features in APP/PS1 transgenic AD mice were investigated. Ten-month-old APP/PS1 transgenic mice overexpressing human amyloid precursor protein (APP695swe) and presenilin 1 (PS1-dE9) were given ICA (30 and 60 mg/kg) or sildenafil (SIL) (2 mg/kg), age-matched wild-type (WT) mice were given ICA (60 mg/kg), and APP/PS1 and WT control groups were given an isovolumic vehicle orally twice a day for four months. Results demonstrated that ICA treatments significantly improved learning and memory of APP/PS1 transgenic mice in Y-maze tasks. The amyloid precursor protein (APP), amyloid-beta (Aβ1-40/42) and PDE5 mRNA and/or protein levels were increased in the hippocampus and cortex of APP/PS1 mice, and ICA treatments decreased these physiopathological changes. Furthermore, ICA-treated mice showed an increased expression of three nitric oxide synthase (NOS) isoforms at both mRNA and protein levels, together with increased NO and cGMP levels in the hippocampus and cortex of mice. These findings demonstrate that ICA improves learning and memory functions in APP/PS1 transgenic mice possibly through the stimulation of NO/cGMP signalling and co-ordinated induction of NOS isoforms.

Mirodenafil for the treatment of erectile dysfunction: a systematic review of the literature

Phosphodiesterase type 5 (PDE5) inhibitors are the most commonly used treatment for erectile dysfunction (ED). Since the launch of sildenafil, several drugs-including mirodenafil, sildenafil citrate (sildenafil), tadalafil, vardenafil HCL (vardenafil), udenafil, and avanafil-have become available. Mirodenafil is a newly developed pyrrolopyrimidinone compound, which is a potent, reversible, and selective oral PDE5 inhibitor. Mirodenafil was launched in Korea in 2007, and an orally disintegrating film of mirodenafil was developed in 2011 for benefitting patients having difficulty in swallowing tablets. This study aimed to review the pharmacokinetic characteristic profile of mirodenafil and report evidence on its efficacy in the case of ED. In addition, we reviewed randomized controlled studies of mirodenafil's daily administration and efficacy for lower urinary tract symptoms.

Increasing cGMP-dependent protein kinase I activity attenuates cisplatin-induced kidney injury through protection of mitochondria function

Cisplatin is widely used to treat malignancies. However, its major limitation is the development of dose-dependent nephrotoxicity. The precise mechanisms of cisplatin-induced kidney damage remain unclear, and the renoprotective agents during cisplatin treatment are still lacking. Here, we demonstrated that the expression and activity of cGMP-dependent protein kinase-I (PKG-I) were reduced in cisplatin-treated renal tubular cells in vitro as well as in the kidney tissues from cisplatin-treated mice in vivo. Increasing PKG activity by both pharmacological and genetic approaches attenuated cisplatin-induced kidney cell apoptosis in vitro. This was accompanied by decreased Bax/Bcl2 ratio, caspase 3 activity, and cytochrome c release. Cisplatin-induced mitochondria membrane potential loss in the tubular cells was also prevented by increased PKG activity. All of these data suggest a protective effect of PKG on mitochondria function in renal tubular cells. Importantly, increasing PKG activity pharmacologically or genetically diminished cisplatin-induced tubular damage and preserved renal function during cisplatin treatment in vivo. Mitochondria structural and functional damage in the kidney from cisplatin-treated mice was inhibited by increased PKG activity. In addition, increasing PKG activity enhanced ciaplatin-induced cell death in several cancer cell lines. Taken together, these results suggest that increasing PKG activity may be a novel option for renoprotection during cisplatin-based chemotherapy.

Infertility in men with spinal cord injury: research and treatment

Spinal cord injury (SCI) occurs most often to young men. Following SCI, most men are infertile due to a combination of erectile dysfunction, ejaculatory dysfunction and semen abnormalities. Erectile dysfunction may be treated by the same therapies that are used in the general population. Similarly, the same treatments that are effective to assist conception in couples with non-SCI male factor patients are effective in assisting conception in SCI male-factor patients. The most apparent differences in male-factor symptoms between SCI and non-SCI patients are the high occurrences of anejaculation and atypical semen profiles in men with SCI. Methods available to assist ejaculation in men with SCI include penile vibratory stimulation and EEJ. Use of surgical sperm retrieval as the first line of treatment for anejaculation in men with SCI is controversial. Most men with SCI have a unique semen profile characterized by normal sperm concentration, but abnormally low sperm motility. Toxic substances in the semen contribute to this problem. Despite impaired sperm parameters, pregnancy outcomes using sperm from men with SCI are similar to pregnancy outcomes using sperm from non-SCI men. Future studies should focus on improving natural ejaculation and improving semen quality in these men.

Parkinson disease: an update

BACKGROUND

Over the past decade, the treatment of Parkinson disease (PD) has undergone tremendous changes. New drugs have been introduced to manage the cardinal motor symptoms of PD, and other agents have been borrowed to treat the nonmotor manifestations of the illness. For neurologists faced with the task of treating PD patients, the available array of medications may be confusing and intimidating.

REVIEW SUMMARY

In this review, I summarize the newest approved medications for the treatment of PD, including the new dopamine agonists and catechol-O-methyl-transferase inhibitors. I also describe agents that are used to treat common problems in PD patients, including hallucinations, orthostasis, nausea, erectile dysfunction, depression, and memory loss. Guidelines for handling common scenarios in PD patients will be illustrated by 10 case histories. Finally, the most promising PD drugs that are currently in development will be reviewed.

CONCLUSIONS

Neurologists have a vast armamentarium to treat both motor and nonmotor manifestations of PD. Understanding this array allows the astute clinician to improve the lives of their patients with PD.