Adherence to phosphodiesterase type 5 inhibitors in the treatment of erectile dysfunction in long-term users: how do men use the inhibitors?

Effects of shRNA-mediated silencing of PDE5A3 on intracellular cGMP and free Ca2+ levels and human prostate smooth muscle cell proliferation from benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) with lower urinary tract symptoms (LUTS) is a common disease among elderly men, for which safe and effective treatment strategies remain limited. The aim of the present study was to explore the potential effects of phosphodiesterase 5A3 (PDE5A3) silencing on human prostate smooth muscle cells (HPSMCs). HPSMCs were initially obtained from patients with BPH/LUTS. Short hairpin RNA (shRNA) targeting the PDE5A3 gene was subsequently transfected into cultured HPSMCs. The expression of PDE5A3 was measured using reverse transcription-quantitative PCR and western blotting. cGMP levels were then measured using western blotting and immunocytochemical staining and intracellular Ca²⁺ concentration was measured using rhod2-AM in HPSMCs after transfection. HPSMC proliferation was also observed within 4 days. Cells transfected with PDE5A3-shRNA2 exhibited the most notable decline in PDE5A3 expression compared with that in the Control or NC groups. cGMP levels in HPSMCs transfected with PDE5A3-shRNA2 was significantly increased compared with those in the Control or NC groups, whereas intracellular Ca²⁺ concentrations in cells in the PDE5A3-shRNA2 group were decreased compared with that in the Control or NC groups. The proliferation of HPSMCs in the PDE5A3-shRNA2 group was also inhibited compared with that in the Control or NC groups after 72 h of culture. In conclusion, shRNA-mediated silencing of PDE5A3 was able to increase the levels of cGMP whilst reducing the concentration of Ca²⁺ in HPSMCs, in turn suppressing their proliferation. These findings may potentially provide a novel therapeutic target for treating BPH/LUTS.

Thinking About Pathomechanisms and Current Treatment of Erectile Dysfunction-"The Stanley Beamish Problem." Review, Recommendations, and Proposals

INTRODUCTION

Up to 50% of all men over 50 years of age suffer from erectile dysfunction. Since the late 1990s erectile dysfunction has been treated mostly with phosphodiesterase 5 inhibitors (PDE5I). Over the past 20 years, numerous scientific findings on the development of erectile dysfunction have been collected, which have so far received little attention in the treatment of erectile dysfunction.

OBJECTIVES

The objectives of this study were to review the existing medical literature on erectile dysfunction regarding physiology, pathophysiology, and especially therapeutic options beyond treatment with PDE5I and to enable a more effective and especially sustainable treatment for erectile dysfunction.

METHODS

A literature review was performed by using PubMed from 1985 to 2020 regarding the physiology, pathophysiology, and treatment of erectile dysfunction.

RESULTS

Since the end of the 1990s an enormous amount of knowledge has been gained about the physiology/pathophysiology of erection/erectile dysfunction. Based on these findings, numerous physical, drug, and holistic therapeutic options (beyond the application of PDE5I) have been developed for the treatment of erectile dysfunction. However, these are still relatively rarely used in the therapeutic concept of erectile dysfunction today.

CONCLUSION

Based on scientific findings of the last 20 years, there are numerous therapeutic approaches, including lifestyle modification, specific pelvic floor exercises, shock wave treatment, and the application of different supplements. The long-term treatment of erectile dysfunction should now go beyond the purely symptomatic use of PDE5I. W-D Beecken, M Kersting, W Kunert, et al. Thinking About Pathomechanisms and Current Treatment of Erectile Dysfunction-"The Stanley Beamish Problem." Review, Recommendations, and Proposals. Sex Med Rev 2021;9:445-463.

Men's beliefs about treatment for erectile dysfunction-what influences treatment use? A systematic review

Successful treatment of erectile dysfunction (ED) is associated with improvements in quality of life; however, treatment utilisation is sub-optimal. The aim of this systematic review was to identify the rates of ED treatment utilisation and the barriers and enablers men experience when using treatment. We searched: MEDLINE^®, Embase, the Cochrane library; AMED; HMIC; HTA; CINAHL; PsychARTICLES; PsychINFO up to August 2018. Data on rates of treatment utilisation and barriers and enablers of utilisation were extracted and summarised. Fifty studies were included. Discontinuation rates ranged from 4.4 to 76% for phosphodiesterase type 5 inhibitors, 18.6 to 79.9% for intracavernosal injections, and 32 to 69.2% for urethral suppositories. In relation to those with a penile prosthesis, 30% discontinued having sex due to, e.g. device complications, lack of partner or a loss of sexual interest. Most research included in the current review examined barriers to treatment utilisation and therefore focussed on reasons for discontinuing treatment. However, a small number explored factors that men found helpful with regards to treatment utilisation. The most prevalent barriers to utilisation were treatment ineffectiveness, side effects, the quality of men's intimate relationships and treatment costs. With regards to treatment enablers, the most salient finding was that men who reported side effects to a healthcare professionals (HCPs) were significantly less likely to discontinue treatment. There were limitations in methodology in that the studies did not use validated measures of treatment utilisation or barriers and enablers and no study used psychological theory to inform the examination of factors that influenced treatment utilisation. This review identifies a number of influential factors relating to ED treatment utilisation and highlights the importance of men's beliefs with regards to ED and its treatment. Beliefs are potentially modifiable and therefore the findings of this review highlight important considerations for HCPs with regards to supporting men to make better use of treatment.

Development of a novel topical formulation of glyceryl trinitrate for the treatment of erectile dysfunction

Erectile dysfunction (ED), defined as the inability to initiate or maintain an erection sufficient for satisfactory sexual intercourse, is common, particularly in men aged ≥50 years. Existing treatments have significant limitations, and there remains a need for a fast-acting (to facilitate spontaneity during intercourse) and well tolerated local therapy. Topical glyceryl trinitrate (GTN) may meet this need because GTN undergoes rapid metabolism in penile smooth muscle and endothelial cells to produce nitric oxide, which plays a key role in the development of erection. This paper describes the rationale for the development of MED2005, a topical GTN formulation using DermaSys® technology, which is undergoing clinical trials for the treatment of ED. Pharmacokinetic studies have shown that MED2005 provides rapid delivery of GTN following application to the glans penis, and a Phase 2(a) trial in men with ED showed that MED2005 produced significant improvements in erectile function, compared with placebo. MED2005 was well tolerated in this trial, with only 21 cases of headache in 1003 intercourse attempts. It is anticipated that MED2005 will provide an effective therapy for ED, with a fast onset of action, good local tolerability, and fewer contraindications than phosphodiesterase 5 inhibitors, the current cornerstone of ED therapy.

Risk of sudden sensorineural hearing loss in adults using phosphodiesterase type 5 inhibitors: Population-based cohort study

PURPOSE

The objective of the study was to determine the risk of sudden sensorineural hearing loss (SNHL) associated with use of phosphodiesterase type 5 (PDE5) inhibitors.

METHODS

We conducted a retrospective cohort study in the MarketScan Commercial Claims and Encounters Database including adult men who initiated a PDE5 inhibitor (n = 377,722) and 1,957,233 nonusers between 1998 and 2007. Periods of drug exposure were assessed on a weekly basis based on pharmacy billing records, assuming use of 1 dose per week (current use). Incident sudden SNHL was defined based on inpatient or outpatient visits with International Classification of Diseases, Ninth Revision, Clinical Modification codes 389.1x, 389.2x, or 388.2 plus ≥2 procedure codes for audiometric hearing testing within ±30 days of sudden SNHL diagnosis. We used age- and propensity score-adjusted Cox proportional hazards model to evaluate the risk of sudden SNHL during periods of current or recent use compared with that of nonuse. We conducted sensitivity analyses by varying the assumed drug utilization frequency and sudden SNHL case definition.

RESULTS

We evaluated 1233 sudden SNHL cases, resulting in an incidence of 4.35, 5.58, and 2.38 per 10,000 person-years for current, recent, and nonuse of PDE5 inhibitors, respectively. Compared with nonuse, the adjusted hazard ratio was 1.25 (1.01-1.55) for current use with a risk difference of 1.97 (1.12-2.82) per 10,000 person-years. For recent use, the adjusted hazard ratio was 1.60 (1.33-1.94) and risk difference was 3.19 (2.24-4.14). Estimates were consistent across the sensitivity analyses.

CONCLUSIONS

Use of PDE5 inhibitors is associated with a small but significantly increased risk of sudden SNHL.

Satisfaction and treatment adherence in erectile dysfunction in the medium and long term

INTRODUCTION

The aim of this study was to show the satisfaction and treatment adherence in erectile dysfunction (ED) in the medium and long term.

MATERIAL AND METHODS

A descriptive, comparative study was conducted in 2 centres through telephone interviews with patients who came for an initial visit between 2012 and 2014 for ED. A complete case history review was conducted on the use of and withdrawal from treatment. For current use, the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) and the Global Assessment Questionnaire (GAQ) were filled out; for past use, only the GAQ was filled out. For the statistical analysis, we employed Fisher's exact test for comparisons of percentages and the Kruskal-Wallis test to compare means.

RESULTS

The study included 250 patients; 20.8% were prescribed intraurethral alprostadil (ALP-IU), 17.2% were prescribed intracavernous alprostadil (ALP-IC), 92.8% were prescribed a first IPD5, and 24.8% were prescribed at least a second IPD5. The treatment withdrawal rate was 62.07% for the first IPD5, 41.94% for the last IPD5, 69.23% for the ALP-IU and 65.11% for the ALP-IC (P=.007). The main reason for withdrawal for the IPD5 was a lack of response (32.76% of those who took IPD5). In addition to withdrawal, there were adverse reactions for ALP-IU and ALP-IC (28.85% and 11.63%, respectively). The mean duration of use until withdrawal was 4.3 months for IPD5, 2.2 months for ALP-IU and 5.5 months for ALP-IC (P=.064). The most favourable GAQ and EDITS scores were observed for IPD5 (EDITS score of 74). Sildenafil and tadalafil had the longest usage times (mean >5 months).

CONCLUSIONS

The withdrawal rate for treating ED is high, with short usage times of a few months. A lack of response and adverse reactions were the main causes for withdrawal. The drugs that provide greater satisfaction are the IPD5, although there are no significant differences in the mean usage time between the different types and in aspects such as the mean usage time to withdrawal or the withdrawal rates.

Erectile Dysfunction Medication Use in Veterans Eligible for Medicare Part D

BACKGROUND

Erectile dysfunction (ED) medications are therapeutically effective and associated with satisfaction. Medicare Part D included ED medications on the formulary during 2006 and inadvertently in 2007-2008.

OBJECTIVE

To characterize phosphodiesterase-5 inhibitor (PDE-5) medication use among veterans who were dually eligible for Veterans Affairs (VA) and Medicare Part D benefits.

METHODS

Veterans aged > 66 years who received PDE-5 inhibitors between 2005 and 2009 were included. Veterans were categorized by PDE-5 inhibitor claims: VA-only, Part D-only, or dual users of VA and Part D-reimbursed pharmacies. T-tests and chi-square tests were applied as appropriate.

RESULTS

From 2005 to 2009, the majority (85.2%) of veterans used VA benefits exclusively for their PDE-5 inhibitors; 11.4% used Medicare Part D exclusively; and 3.4% were dual users. The Part D-only group was older, more frequently not black, had a VA copay, and had a higher income (P < 0.03). The VA group was more likely to have comorbidities, smoke, and have a history of substance abuse (P < 0.001). With the inception of Medicare Part D in 2006, the number of patients filling prescriptions for PDE-5 inhibitors (-68%) and total number of PDE-5 inhibitor 30-day equivalents dispensed (-86.7%) from the VA decreased. Part D prescriptions increased through 2006 (full coverage period) and 2007 (accidental partial coverage) and decreased in 2008. While Part D accounted for only 10% of PDE-5 inhibitor 30-day equivalents, it equaled 29.2% of dispensed tablets. In October 2007, VA PDE-5 inhibitor use returned to 2005 levels.

CONCLUSIONS

Implementation of Medicare Part D reduced VA PDE-5 inhibitor acquisition. However, after removal of PDE-5 inhibitors from the Part D formulary, use of VA pharmacies for PDE-5 inhibitors resumed. Medication policies outside the VA can affect medication use. Veterans with access to non-VA health care may obtain medications from the private sector because of VA restrictions. This may be especially true for nonformulary and lifestyle medications.

DISCLOSURES

The authors received funding support for this research project from the Department of Veterans Affairs, Veterans Health Administration, Health Services Research and Development Service as grant IIR 07-165-2. The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs or Health Services Research and Development Service. Study concept and design were contributed by Smith and Stroupe, assisted by the other authors. Huo, Bailey, and Stroupe took the lead in data collection, assisted by the other authors. Data interpretation was performed by Spencer and Suda, along with Smith and Stroupe and assisted by Huo and Bailey. The manuscript was primarily written by Spencer and Suda, with assistance from the other authors, and revised by Spencer, along with the other authors.

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.

Role of C-type natriuretic peptide in the function of normal human sperm

C-type natriuretic peptide (CNP) is a newly discovered type of local regulatory factor that mediates its biological effects through the specific, membrane-bound natriuretic peptide receptor-B (NPR-B). Recent studies have established that CNP is closely related to male reproductive function. The aims of this study were to determine the distribution of CNP/NPR-B in human ejaculated spermatozoa through different methods (such as immunolocalization, real time polymerase chain reaction and Western Blot), and then to evaluate the influence of CNP on sperm function i n vitro, such as motility and acrosome reaction. Human semen samples were collected from consenting donors who met the criteria of the World Health Organization for normozoospermia. Our results show that the specific receptor NPR-B of CNP is localized in the acrosomal region of the head and the membrane of the front-end tail of the sperm, and there is no signal of CNP in human sperm. Compared with the control, CNP can induce a significant dose-dependent increase in spermatozoa motility and acrosome reaction. In summary, CNP/NPR-B can affect sperm motility and acrosome reaction, thus regulating the reproductive function of males. CNP may be a new key factor in regulating sperm function.

Association of erectile dysfunction with depression in patients with chronic viral hepatitis

AIM: To investigate the prevalence of erectile dysfunction (ED) and its association with depression in patients with chronic viral hepatitis.

METHODS: This single center cross-sectional study was conducted from August 2013 through January 2014. All outpatients with chronic viral hepatitis in our liver clinic between 18 and 80 years of age were considered eligible for this study. The exclusion criteria included well-established causes of ED, such as diabetes, hypertension, hyperlipidemia, alcohol abuse, liver cirrhosis, ischemic heart disease, renal disease, neurologic disease, and malignancy. We also excluded the patients who had incompletely answered the questionnaires. ED was assessed using the validated Korean version of the International Index of Erectile Function (IIEF-5) scale. The Korean version of the self-administered Beck Depression Inventory (BDI) scale was used to assess depression in the patients. Demographic and medical data were obtained from the patients’ medical records. Current or past history of psychiatric diagnosis and drug history including the use of an antiviral agent and an antidepressant were also recorded.

RESULTS: A total of 727 patients met the initial eligibility criteria. Six hundred seventeen patients were excluded because their medical records contained one or more of the previously determined exclusion criteria. The remaining 110 patients were assessed based on the BDI and IIEF-5 questionnaires. Based on the IIEF-5 scale, the prevalence of ED among patients with chronic viral hepatitis was 40%. Compared with the non-ED group, patients in the ED group were older. The proportion of patients in the ED group who had a job or who were naïve peg-interferon users was lower than that in patients in the non-ED group. Patients with ED had significantly lower scores on the IIEF-5 scale than patients without ED (11.75 ± 4.88 vs 21.33 ± 1.86, P = 0.000). Patients with ED rated significantly higher scores on the BDI scale compared with patients without ED (12.59 ± 7.08 vs 5.30 ± 4.00, P = 0.000). Also, the IIEF-5 scores were negatively correlated with age, employment, and BDI scores. In the multiple logistic regression analysis, age and depression were independently associated with erectile dysfunction (P = 0.019 and 0.000, respectively).

CONCLUSION: Patients with chronic viral hepatitis have a high prevalence of ED. Age and depression are independent factors for ED in male patients with chronic viral hepatitis.