Evaluation and Management of Erectile Dysfunction in the Hypertensive Patient

Efficacy and safety of PDE5 inhibitors in middle-aged and old patients with and without hypogonadism

PURPOSE

Although several reviews have evaluated the use of PDE5 inhibitors (PDE5i) for treating erectile dysfunction (ED), their specific use in middle-aged and old patients has not been fully evaluated. Given that elderly patients with ED often have a complex combination of systemic and sexual health risk factors, the safety and efficacy of PDE5i in such a context are hereby reviewed.

MATERIALS AND METHODS

A thorough examination of existing literature has been conducted on PubMed.

RESULTS

PDE5i has good safety and efficacy, but the situation is more complex for patients with hypogonadism than those with normal testosterone levels, with reduced responsiveness to PDE5i. In this case, combination therapy with testosterone is recommended, safe and effective.

CONCLUSIONS

Eliminating or reducing reversible risk factors and controlling or slowing the development of irreversible factors is an important foundation for using PDE5i to treat ED in all patients, especially middle-aged and elderly ones.

Genetically predicted hypertension, antihypertensive drugs, and risk of erectile dysfunction: a Mendelian randomization study

Background

The causal relationship between hypertension, antihypertensive drugs and the risk of erectile dysfunction is still uncertain. We performed a univariable and multivariable Mendelian randomization study to investigate whether they are causally related to erectile dysfunction.

Methods

Genetic variants associated with blood pressure were derived from the genome-wide association study meta-analysis of the UK Biobank and International Consortium of Blood Pressure (N = 757,601). Summary association data for hypertension were obtained from the UK Biobank (N = 463,010) and the FinnGen study (N = 356,077). The summary statistics of erectile dysfunction were obtained from the European ancestry with 223,805 subjects. The SNP instruments used to assess the effect of the protein targets of antihypertensive drugs on erectile dysfunction were obtained from previous studys. Causal effects were estimated using the univariate Mendelian randomization method (inverse variance weighted, MR-Egger, weighted median, MR-PRESSO and Wald ratios) and the multivariate Mendelian randomization method. Sensitivity analyses were implemented with the Cochran's Q-test, MR-Egger intercept test, MR-PRESSO, and leave-one-out analysis.

Results

Univariate MR found that elevated diastolic blood pressure may increase the occurrence of erectile dysfunction (odds ratio [OR] = 1.012; 95% confidence interval [CI]: 1.000-1.024; P = 0.047). Genetically predicted hypertension is also associated with ED (For the FinnGen, OR = 1.106; 95% CI: 1.027-1.191; P = 0.008. For the UK Biobank, OR = 3.832; 95% CI: 1.410-10.414; P = 0.008). However, after adjusting for systolic blood pressure, diastolic blood pressure and hypertension using multivariate Mendelian randomization, only hypertension was causally associated with ED occurrence (For the FinnGen, OR = 1.103; 95% CI: 1.018-1.195; P = 0.017. For the UK Biobank, OR = 5.037; 95% CI: 1.601-15.846; P = 0.006). We found no evidence that the use of angiotensin-converting enzyme inhibitors, beta-blockers, calcium channel blockers, and thiazide diuretic increased the risk of erectile dysfunction.

Conclusions

Genetically predicted hypertension increases the risk of erectile dysfunction, but we found no causal relationship between elevated systolic/diastolic blood pressure and erectile dysfunction. We speculate that the relationship between elevated blood pressure and erectile dysfunction risk may be nonlinear. We found little evidence that antihypertensive drugs increase the risk of erectile dysfunction.

Effectiveness of bisoprolol versus other β-blockers and other antihypertensive classes: a cohort study in the Clinical Practice Research Datalink

Aim: To compare blood pressure (BP) and safety outcomes in patients with hypertension initiating bisoprolol, versus other β-blockers, angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers, calcium channel blockers or diuretics. Materials & methods: New user cohort study. Patients initiating bisoprolol were matched with up to four patients, in each comparator cohort using propensity score. BP outcomes were compared using linear mixed models and safety outcomes using Cox proportional hazards. Results: Differences in average systolic and diastolic BP variation were ≤3 mmHg between bisoprolol versus the compared classes. No difference was observed in risk of diabetes, obesity or erectile dysfunction. An increased dyslipidemia risk was only observed versus diuretics (hazard ratio: 0.76; 98.75% CI: 0.58, 0.99). Conclusion: No differences in BP variation and safety outcomes.

Analysis of integrated clinical safety data of tadalafil in patients receiving concomitant antihypertensive medications

This pooled safety analysis assessed the incidence of hypotension‐related treatment‐emergent adverse events (TEAEs) and major adverse cardiovascular events (MACEs) in patients with concomitant use of tadalafil and antihypertensive medications. Data were pooled from seventy‐two Phase II–IV studies conducted on patients with a diagnosis of erectile dysfunction (ED) and/or benign prostate hyperplasia (BPH). Studies were categorized as either All placebo‐controlled studies or All studies. The incidences of hypotension‐related TEAEs and MACEs were analyzed by indication; by use of concomitant antihypertensive medications; and by the number of concomitant antihypertensive medications. A total of 15 030 and 22 825 patients were included in the analyses for All placebo‐controlled studies and All studies, respectively. In the All placebo‐controlled studies, the incidence of hypotension‐related TEAEs and MACEs was ranging between 0.6–1.5% and 0.0–1.0%, respectively, across all indications. Tadalafil was associated with an increase in hypotension‐related TEAEs only in the ED as‐needed group not receiving any concomitant antihypertensive medications (p‐value = .0070); no significant difference was reported between placebo and tadalafil in the groups of patients receiving ≥1 antihypertensive medication (p‐values ≥ .7386). Similarly, no significant differences (p‐values≥ .2238) were observed in the incidence of MACEs between tadalafil and placebo treatment groups, with or without concomitant use of antihypertensive medications, and across all indication categories. In the All studies group, results were similar. The pooled analysis showed no evidence that taking tadalafil alongside antihypertensive medications increases the risk of hypotension‐related TEAEs or MACEs compared with antihypertensive medications alone.

Frequency of Iatrogenic Sexual Dysfunction Associated with Antihypertensive Compounds

Iatrogenic sexual dysfunction (SD) caused by antihypertensive (AH) compounds, provoking sexual desire, orgasm or arousal dysfunction, is a common clinical adverse event. Unfortunately, it is often underestimated and underreported by clinicians and prescribers in clinical practice, deteriorating the adherence and patient quality of life. The objective of this study was to investigate the frequency of SD in patients treated with different antihypertensive compounds; a real-life naturalistic and cross-sectional study in patients receiving AH treatment was carried out. Method: A total of 256 patients were included in the study (188 males and 68 females who met the inclusion and exclusion criteria). The validated Psychotropic-Related Sexual Dysfunction Questionnaire (PRSexDQ-SALSEX) was transversally applied once at least every two months following the onset of the treatment in order to measure possible AH-related SD. Although the spontaneous reporting of SD was very low (6.81% females/24.8% males), 66.40% of the patients reported impaired sexual function through the SALSEX questionnaire after the treatment onset, as follows: decreased desire (55.8% females/54.2% males), delayed orgasm (42.6%/45.7%), anorgasmia (42.6%/43.6%) and arousal difficulties (53%/59.6%). The average frequency of moderate to severe iatrogenic SD was 66.4% with AH in monotherapy as follows: angiotensin II receptor antagonists (ARBs), 29.8%; calcium antagonists, 40%; diuretics, 42.9%; beta blockers, 43.8%; and angiotensin-converting enzyme (ACE) inhibitors, 77.8%. Combined treatments showed a higher percentage of main SD (70.3%): diuretic + ACE inhibitor, 42.3%; ARB + calcium antagonist, 55.6%; diuretic + calcium antagonist, 68.8%; and diuretic + ARB, 74.2%. The greatest risk factors associated with SD were poor general health, age over 60 with a comorbid coronary or musculoskeletal disease, mood disorder and diuretic +ARB combined therapy. Conclusion: SD is common in patients treated with antihypertensive drugs, and it is still underreported. The most harmful treatment deteriorating sexual function was the combination of diuretic +ARB, while the least harmful was monotherapy with ARBs. More research is needed on the clinical management of this problem to preserve the quality of life of patients and their partners.

Complete study for erectile dysfunction (CompED) improving diagnosis and treatment decision-making

Erectile dysfunction is a condition associated with increasing age. Patient evaluation and management should follow a comprehensive, stepwise approach. The aim of this article was to report our experience with the complete study for erectile dysfunction, including intracavernous injection rigidity test, biothesiometry and colour duplex Doppler ultrasound. Data were collected and analysed prospectively. The primary end point was to determine whether treatment decision-making was eased by the CompED test. Secondary end points were to establish which clinical variables prior to the study could impact the results of the CompED test, to finally improve patient selection for the study. 187 patients were recruited, 31.2% of the patients had an axial rigidity below 50%, 28.5% had a peak systolic velocity <25 cm/s, 13.2% had an end-diastolic velocity >5cm/s and 27.5% had an abnormal biothesiometry. The factors that best predicted an abnormal result in any of the tests were age >70 years, IIEF domain A < 14 points, and previous radical prostatectomy or radiotherapy. The CompED test stands as a new alternative for the evaluation of patients with erectile dysfunction, being less time consuming, aiding in a more accurate determination of the aetiology and guiding treatment decision-making.

The efficacy of bosentan combined with vardenafil in the treatment of postoperative pulmonary hypertension in children with congenital heart disease: A protocol of randomized controlled trial

Background:

Congenital heart disease in children with pulmonary hypertension is a common and serious complication, which has a direct impact on the surgical effect and prognosis of children. Bosentan and vardenafil are commonly used drugs for the treatment of postoperative pulmonary hypertension in children with congenital heart disease, and there are few clinical studies on their combined use. Therefore, the purpose of this randomized controlled trial is to evaluate the effectiveness and safety of the combined use of 2 drugs in the treatment of postoperative pulmonary hypertension in children with congenital heart disease.

Methods:

This is a prospective randomized controlled trial to study the effectiveness and safety of bosentan combined with vardenafil in the treatment of postoperative pulmonary hypertension in children with congenital heart disease. Approved by the clinical research ethics committee of our hospital. The patients were randomly divided into 1 of 2 treatment regimens:

Patients, doctors, nurses, and data collection assistants were blinded to group allocation. Observation indicators include: oxyhemoglobin saturation (SpO2), 6-min Walking Test Distance (6 MWTD), systolic pulmonary artery pressure, mean pulmonary artery pressure, Borg score, NYHAFC score, etc. Data were analyzed using the statistical software package SPSS version 25.0 (Chicago, IL).

Discussion:

This study will evaluate the effectiveness and safety of bosentan combined with vardenafil in the treatment of pulmonary hypertension after congenital heart disease in children. The results of this experiment will provide a clinical basis for the use of bosentan combined with vardenafil to treat pulmonary hypertension after congenital heart disease in children.

Ethics and dissemination:

Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval was not required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences.

OSF Registration number:

DOI 10.17605/OSF.IO/962BT.

Apomorphine for the Treatment of Erectile Dysfunction: Systematic Review and Meta-Analysis

Sublingual apomorphine could be an option in patients with erectile dysfunction who cannot take phosphodiesterase type 5 inhibitors (e.g., using nitrates). We have completed a systematic review to evaluate the effects of sublingual apomorphine comparing with placebo for treating erectile dysfunction. The evidence searching process finished on 9 January 2019. We included nine randomized controlled trials (RCTs). Treatment length varied from 4 to 8 weeks and doses ranged from 2 to 6 mg. The percent of successful sexual intercourse attempts per ingested dose of apomorphine was evaluated in eight studies. All the studies found that apomorphine was better than placebo (6-27% more successful intercourse attempts than with placebo), but differences were not statistically significant in one study done in patients previously treated with radical prostatectomy. Regarding erectile function scores, three studies reported higher improvement on the erectile function scores for apomorphine. Differences with placebo were not clinically relevant in another two studies, one in which only diabetic patients were included and one in which only patients with radical prostatectomy were involved. Discontinuation of treatment due to adverse events was higher for apomorphine, particularly for higher doses. Available evidence suggests that sublingual apomorphine is more effective than placebo, except for patients previously treated with radical prostatectomy, and is generally well tolerated at doses of 2 or 3 mg. Nowadays, sublingual apomorphine is the only licensed oral drug for erectile dysfunction not absolutely contraindicated with nitrates use, and more RCTs should be performed to evaluate its effects and safety for treating ED.

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

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

Association of erectile dysfunction and type II diabetes mellitus at a tertiary care centre of south India

BACKGROUND AND AIMS

Erectile Dysfunction (ED) is more common in diabetic men and, unfortunately, occurs at an earlier age in diabetic patients when compared with the general population. The study aims to evaluate the independent predictors of ED in adult men with type 2 diabetes mellitus (DM) at a tertiary care center of South India.

METHODS

A total of 720 men aged 30-70 years who had been diagnosed with type 2 DM were enrolled for the study from January 2017 to January 2020 from the outpatient diabetes clinic of the Hospital. All patients completed the abridged version of the International Index of Erectile Function (IIEF-5) questionnaire.

RESULTS

The mean age of the patients was (58.4 ± 7.8 years). 68.6% of subjects had varying degrees of erectile dysfunction, of which 54.6% had moderate to severe ED. 55.8% had poor glycemic control (HbA1c ≥ 7%). Subjects with ED had a longer duration of DM than those without ED (mean DM duration was 8.1 ± 4.9 years versus 4.4 ± 3.5 years; p < 0.001). Longer duration of DM, poor glycemic control, hypertension, peripheral arterial disease, testosterone deficiency were all independent predictors ED (p < 0.05).

CONCLUSIONS

A high incidence of erectile dysfunction was observed in type 2 DM patients attending the diabetic clinic, and over half of the people affected were of moderate-to-severe in intensity. Poor glycemic control, testosterone deficiency, peripheral arterial disease were the modifiable risk factors for ED in diabetic subjects. At the same time, a longer duration of type 2 DM was noticed as a glaring non-modifiable risk factor, according to our study.

Silencing Nogo-B receptor inhibits penile corpus cavernosum vascular smooth muscle cell apoptosis of rats with diabetic erectile dysfunction by down-regulating ICAM-1

Erectile dysfunction (ED) is a major sexual problem for men. Nogo-B receptor (NgBR) has been found to be involved in the regulation of vascular remodeling and angiogenesis. The present study explores the effects of NgBR in penile corpus cavernosum in rats with diabetic ED. Firstly, the ED model of Sprague Dawley rats was established. Hematoxylin-eosin staining and Masson staining were conducted to observe pathological morphology. Immunochemical assay was adopted to detect α-smooth muscle actin (α-SMA), NgBR and intercellular cell adhesion molecule-1 (ICAM-1) expression. Reverse transcription quantitative polymerase chain reaction assay and Western blot analysis were carried out for the assessment of NgBR, factors correlated to ICAM-1, including steroid receptor coactivator (SRC) and proline-rich tyrosine kinase2 (PYK2), and factors associated with apoptosis, including B-cell lymphoma-2 (Bcl-2), Bcl-2 associated protein X (Bax), caspase 3 and cleaved-caspase 3. The results found that capillaries and vascular smooth muscle cell content reduced, and NgBR and ICAM-1 were elevated in rats with diabetic ED. si-NgBR relieved ED by decreasing penile corpus cavernosum smooth muscle systolic percentage and increasing erectile time and rate, intracavernous pressure (ICP)/mean arterial pressure (MAP) and diastolic percentage, improving the pathological changes and inhibiting cavernosum cell apoptosis. si-NgBR also resulted in the down-regulation of ICAM-1 and downstream SRC and PYK2 and promoted α-SMA expression. In conclusion, si-NgBR can provide a potential therapy for diabetic ED in rats by down-regulating ICAM-1, SRC and PYK2, making it a potential therapeutic option for diabetic ED.

TRPM8 channel activation triggers relaxation of pudendal artery with increased sensitivity in the hypertensive rats

INTRODUCTION

Erectile dysfunction (ED) is frequently encountered in patients with arterial hypertension and there is a recent functional correlation between the expression of thermoreceptor channels TRPM8 (melastatin 8) and alterations in blood pressure in hypertension. The aim of this study was to investigate the function of cold-sensing TRPM8 channel in internal pudendal artery (IPA) in both normotensive and hypertensive rats.

METHODS

We performed experiments integrating physiological, pharmacological, biochemical and cellular techniques.

RESULTS

TRPM8 channels are expressed in the IPA and in vascular smooth muscle cells from IPA. In addition, TRPM8 activation, by both a cooling compound icilin (82.1 ± 3.0%, n = 6) and cold temperature [thermal stimulus, basal tone (25 °C, 41.2 ± 3.4%, n = 5) or pre-contracted tone induced by phenylephrine (25 °C, 87.0 ± 3.6%, n = 7)], induced relaxation in IPA. Furthermore, the results showed that the concentration-response curve to icilin was significantly shifted to the right in different conditions, such as: the absence of the vascular endothelium, in the presence of L-NAME (10^-4 M), or indomethacin (10^-5 M) or by a combination of charybdotoxin (10^-7 M) and apamin (5 × 10^-6 M), and Y27632 (10^-6 M). Interestingly, icilin-induced vasodilation was significantly higher in IPA from spontaneously hypertensive (SHR, E₁₀^-4_{M =} 75.3 ± 1.7%) compared to wistar rats (E₁₀^-4_{M =} 56.4 ± 2.6%), despite no changes in the TRPM8 expression in IPA between the strains, suggesting that the sensitivity of TRPM8 channels is higher in SHR.

CONCLUSIONS

These data demonstrate for the first time, the expression and function of TRPM8 channels in the IPA involving, at least in part, endothelium-derived relaxing factors and ROCK inhibition. Overall, this channel could potentially be a new target for the treatment of hypertension associated-ED.

Erectile dysfunction in patients with arterial hypertension. Cardiovascular risk and impact on their quality of life

OBJECTIVES

Estimate the frequency of erectile dysfunction in patients with essential hypertension and associated variables, degree of control, cardiovascular risk and the impact on quality of life.

MATERIAL AND METHODS

Type of study: Observational study of prevalence in men with essential hypertension.

MEASUREMENTS

Sociodemographic and comorbidity variables were collected from each patient (age, Charlson index, dyslipidaemia and prostatic hyperplasia), degree of control of essential hypertension and treatment, cardiovascular risk and metabolic syndrome. The erectile dysfunction was diagnosed by the International Index of Erectile Function (IIEF-15). Quality of life questionnaires were carried out in essential hypertension (MINICHAL), and the international scale of prostatic symptoms (IPSS).

RESULTS

The study included 262 hypertensive men with an average age of 65.84years. Erectile dysfunction was presented in 46.1%, being severe in 54.9%. The bivariate analysis shows an independent association between erectile dysfunction and the variables: age, Charlon index, dyslipidaemia, benign prostatic hypertrophy, diastolic blood pressure, years of diagnosis of hypertension, number of treatments, Regicor and Framingham-Wilson, glycaemia, creatinine and GPT, glomerular filtration through the MDRD formula, irritative symptomatology (IPSS) and somatic manifestations (MINICHAL). The final multivariate model found association with age, presentation of dyslipidaemia, prostatic hyperplasia and metabolic syndrome.

CONCLUSIONS

Erectile dysfunction is significantly associated with age, dyslipidaemia, benign prostatic hypertrophy and metabolic syndrome.

Misdiagnosis And Undertreatment Of Erectile Dysfunction In The Portuguese Primary Health Care

Introduction

The importance of erectile dysfunction (ED) diagnosis and treatment has been highlighted since the early 2000s. However, nearly 20 years after the first phosphodiesterase 5 inhibitor (PDE5i) was marketed, underdiagnosis and undertreatment of ED in the primary health care setting may still be present.

Aim

To assess the relative frequency of patients who are medically treated for ED before referral to specialized urology care. The secondary objectives were to evaluate possible reasons for non-treatment prior to referral and other signs of undertreatment, namely cardiovascular risk assessment and antihypertensive treatment.

Methods

200 male patients referred for ED to specialist urology care by general practitioners were screened after consent between January 2016–December 2018. A full standardized medical and sexual history were taken. Previous medical treatment of ED, namely pharmacologic name and dosages, and cardiovascular risk factors were noted.

Main Outcome Measures

Of the 115 included patients, only 33.9% of patients had already taken PDE5i before referral, and none had taken alprostadil by intracavernous route.

Results

The mean patient age was 58.68 ± 10.01 years old. Only 45.2% had been prescribed the highest dose of PD5i. From the remaining untreated patients, only 19.7% had ≥3 cardiovascular risk factors, including 5.6% of patients who also presented moderate-to-severe stable or unstable angina requiring a stress test or cardiology assessment before treatment. Regarding the 54 patients with medical history of arterial hypertension, 43.4% and 30.2% were treated for hypertension with a diuretic and a beta blocker, respectively.

Conclusion

More focus on the primary healthcare continuous medical education regarding sexual dysfunction, namely ED, is needed because major undertreatment of ED is still present because low prescription of PD5i before referral is noted.

Morgado A, Moura ML, Dinis P, et al. Misdiagnosis And Undertreatment Of Erectile Dysfunction In The Portuguese Primary Health Care. Sex Med 2019;7:177–183.

Impact of the baseline study with penile doppler ultrasound in patients with prostate cancer before radical prostatectomy

INTRODUCTION

Given the high prevalence of erectile dysfunction in male population between 40-70 years old and the effect of radical prostatectomy on this domain, it is important to perform a baseline study.

MATERIAL AND METHODS

Prior radical prostatectomy, erectile function has been assessed prospectively in 112 prostate cancer patients using the erectile function (EF) domain of the International Index of Erectile Function (EF-IIEF), Erectile Hardness Score (EHS) and a penile doppler ultrasound (PDUS). Comorbidities and Charlson index were collected. The EORTC QLQ C-30 and PR-25 tests were administered.

RESULTS

According to EF-IIEF questionnaire, 50.9% of patients showed normal EF and EHS grade 3-4 erection was achieved in the 75.9%. PDUS was normal only in 28.6% of patients and 51.8% showed arterial insufficiency. We found a significant association (P<.0001) between categorized EF-IIEF (normal, mild/moderate/severe) and the EHS value. Between PDUS (normal vs. pathologic) and EHS (3-4 vs. 1-2) statistically significant association (P=.005) was found. Just 35.3% of patients with EHS 3-4 showed normal PDUS. Correlation between the PDUS and the EF-IIEF (≥26 vs.<26) was statistically significant (P=.043). Moreover, only 38.6% of patients with EF-IIEF≥26 had a normal PDUS.

CONCLUSIONS

In order to predict EF recovery after surgery, global assessment is required. Solely self-administered tests are not enough. In this baseline study, PDUS can play an important role.

PnPP-19 Peptide Restores Erectile Function in Hypertensive and Diabetic Animals Through Intravenous and Topical Administration

INTRODUCTION

With the aim of overcoming the high toxicity of PnTx2-6 (or δ-CNTX-Pn2a), a toxin from the venom of the armed spider (Phoneutria nigriventer), the 19-aminoacid peptide, PnPP-19 (P nigriventer potentiator peptide), was synthesized based on molecular modeling studies of PnTx2-6. PnPP-19 improved the erectile function of normotensive rats and mice, without eliciting side effects, and no signs of toxicity were observed. In addition, PnPP-19 was able to potentiate the effect of sildenafil.

AIM

To evaluate the efficacy of PnPP-19 in hypertensive and diabetic mouse/rat models in restoring erectile function, after topical administration; verify the biodistribution of PnPP-19 administration (topical and intravenous), permeation, and cyclic guanosine monophosphate (cGMP)/nitric oxide via implication.

METHODS

Corpus cavernosum relaxation was evaluated using cavernous strips from male spontaneous hypertensive rats (SHR) and from streptozotocin (STZ)-diabetic mice contracted with phenylephrine and submitted to electrical field stimulation before and after incubation with PnPP-19 (10^-8 mol/L, 10 minutes) or vehicle. This procedure was also used to determine cGMP/nitric oxide levels, at 8 Hz and to check the effect of PnPP-19 with sildenafil citrate. Biodistribution assays were performed using iodine 123-radiolabeled PnPP-19. In vivo erectile function was evaluated using intracavernosal pressure/main arterial pressure ratio in STZ-diabetic rats after PnPP-19 topical administration.

MAIN OUTCOME MEASURES

PnPP-19 may become a new drug able to fill the gap in the pharmacologic treatment of erectile dysfunction, especially for hypertensive and diabetic individuals RESULTS: PnPP-19 potentiated corpus cavernosum relaxation, in both control and SHR rats. SHR-cavernosal tissue treated with PnPP-19 (1-32 Hz) reached the same relaxation levels as control Wistar rats (16 and 32 Hz). PnPP-19 treatment improved cavernosal tissue relaxation in STZ-diabetic mice and rats. PnPP-19 enhanced cGMP levels in STZ-diabetic mice corpus cavernosum strips. After topical or intravenous administration in rats, ¹²³I-PnPP-19 was mainly recruited to the penis. When topically administered (400 μg/rat), PnPP-19 restores erectile function in STZ-diabetic rats, also improving it in healthy rats by increasing the intracavernosal pressure/main arterial pressure ratio. PnPP-19 exhibited an additive effect when co-administered with sildenafil, showing a novel mode of action regardless of phosphodiesterase type 5 inhibition.

CLINICAL IMPLICATIONS

PnPP-19 seems to be an indicated drug to be tested to treat ED in diabetic and hypertensive patients.

STRENGTH & LIMITATIONS

PnPP-19, although active by topical application and showing safety to human beings (not shown), has low permeability, about 10% of the applied dose.

CONCLUSION

Our results showed that PnPP-19 may emerge as a potent new drug that can be topically administered, becoming a promising alternative for erectile dysfunction treatment. Nunes da Silva C, Pedrosa Nunes K, De Marco Almeida F, et al. PnPP-19 Peptide Restores Erectile Function In Hypertensive And Diabetic Animals Through Intravenous And Topical Administration. J Sex Med 2019;16:365-374.

Pharmacotherapy for erectile dysfunction in diabetic males

INTRODUCTION

Numerous studies have highlighted the intimate association between erectile dysfunction (ED) and diabetes mellitus (DM). However, the true pathogenesis of ED among diabetic men has not yet been fully discovered. The treatment of ED in diabetic patients remains an interesting area of research. The last two decades have witnessed phenomenal advances in the management of ED with the efficacy of pharmacotherapy for ED in diabetic patients encouraging, especially with introduction of innovative conservative tools for treatment.

AREAS COVERED

The aim of this review is to discuss the currently available information on ED pharmacotherapy in diabetic males and provide an expert perspective on the current treatment strategies.

EXPERT OPINION

Conservative treatment remains the initial step for the treatment of ED in diabetic patients. This kind of therapy consists of different modalities including: oral treatments, intracavernosal pharmacotherapy, and evolving modalities such as soluble guanylate cyclase activators, stem cells (SCs), and alternative treatments such as herbal treatment and transdermal/topical pharmacotherapy. However, it should be noted that the currently available pharmacotherapy is still far from ideal. One hopes to witness new drugs and technologies that may revolutionize ED treatment in the future, especially in such complex cases as DM.