Sildenafil taken at bedtime significantly increases nocturnal erections: results of a placebo-controlled study

The efficacy of combination therapy with Ningmitai capsule and sildenafil in men with chronic prostatitis/chronic pelvic pain syndrome and erectile dysfunction: a prospective, multicenter, randomized controlled trial

Background

A high proportion of men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) present with comorbid erectile dysfunction (ED), but evidence-based therapeutic interventions specifically targeting this patient population remain understudied in clinical trials.

Aim

To assess the efficacy of Ningmitai capsule (NMT), an oral traditional Chinese herbal formulation, combined with sildenafil versus monotherapy in alleviating symptoms among a cohort of participants with CP/CPPS and ED.

Methods

A multi-center, randomized clinical trial was conducted from March 2019 to December 2022 at six tertiary hospitals in China. A total of 214 participants diagnosed with CP/CPPS and ED were randomized 1:2:2 to receive orally sildenafil (25 mg, q.n.), NMT (0.38 g × 4 capsules, t.i.d.), or a combination of both for 4 weeks. Validated Chinese version of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI), the International Index of Erectile Function-5 (IIEF-5) and the Erection Hardness Score (EHS) questionnaires were administered at baseline, week 2, and week 4.

Outcomes

The primary endpoint was the reduction in NIH-CPSI pain domain scores from baseline to week 4.

Results

All treatment groups exhibited statistically significant decreases in NIH-CPSI total, pain, urinary and quality of life (QoL) domain scores within 2 weeks, with improvements sustained until the end of the treatment. The combination group demonstrated superior pain score reductions versus sildenafil monotherapy at both timepoints (week 2: mean difference [MD] -2.82 ± 3.27 vs. -1.26 ± 3.45, P = 0.043; week 4, MD -3.57 ± 3.50 vs. -1.07 ± 2.94, P = 0.009). Notably, combination therapy achieved greater IIEF-5 score enhancements compared to NMT alone (P < 0.05) and higher responder rates than either sildenafil or NMT monotherapy (P < 0.05). No significant differences were found among the three arms concerning EHS. No adverse events were reported.

Clinical Implications

NMT-sildenafil combination therapy may serve as a viable alternative to α-blocker-based regimens for CP/CPPS-ED patients, potentially circumventing the orthostatic hypotension risk associated with the concurrent use of phosphodiesterase 5 inhibitors (PDE5i) and α-blockers.

Strengths and Limitations

Strengths include a prospective randomized design, which is well controlled. Limitations encompass the absence of placebo control and long-term follow-up.

Conclusion

NMT-sildenafil combination therapy demonstrates significantly greater benefits of ameliorating pain symptoms and improving erectile function in men with CP/CPPS and ED compared to either monotherapy, with favorable tolerability profiles.

Registration

The study protocol was reviewed and approved by the institutional ethics committee and was registered at ClinicalTrials.gov (NCT06064448).

Novel predictive risk factor for erectile dysfunction: Serum high-sensitivity C-reactive protein

BACKGROUND

C-reactive protein (CRP), as a marker of inflammation, may be closely related to erectile dysfunction (ED), however, there is no meta-analysis exists for it.

OBJECTIVES

We aimed to verify the relationship between CRP and erectile dysfunction and to explore the changes of CRP levels in ED patients after first-line treatment.

MATERIALS AND METHODS

We searched databases including the Cochrane Library, PubMed, and MEDLINE to identify studies up to January 1, 2022. We performed a comprehensive analysis of the included studies by STATA software and calculated standardized mean differences (SMDs) and their corresponding 95% confidence intervals.

RESULTS

A total of 12 studies were included and the analysis showed that CRP levels were higher significantly in patients with erectile dysfunction than the healthy controls (P < 0.001) and decreased by a mean of 0.38 mg/L after first-line PDE5i drug treatment (P = 0.001).

DISCUSSION AND CONCLUSION

This novel meta-analysis suggests that CRP is statistically significantly associated with erectile dysfunction and may be a predictor or risk factor for the assessment of ED. However, further original studies with large sample sizes are needed to validate this. This article is protected by copyright. All rights reserved.

Selecting an Individualized Treatment Approach: The Predictive Value of Erotic Stimulation and Nocturnal Erections for Efficacy of Tadalafil and Cure in Patients With Erectile Dysfunction

PURPOSE

This study aimed to evaluate two modes of Rigiscan for predicting tadalafil response, and to identify which Rigiscan variables are the most efficient at making these predictions.

METHODS

All patients received at least two rounds of nocturnal penile tumescence and rigidity (NPTR) testing and/or audiovisual sexual stimulation (AVSS), then completed the International Index of Erectile Function-5 (IIEF-5) questionnaire, followed by oral 5 mg tadalafil daily for 4 weeks. After a 4-week washout period, all respondents underwent an the IIEF-5 questionnaire again. ED patients were then categorized into tadalafil responders and tadalafil non-responders, who were then further divided into cured patients and uncured patients.

RESULTS

When predicting tadalafil responders, the area under the curve (AUC) of NPTR was superior to that of AVSS (0.68~0.84 VS 0.69~0.73), and the predicted optimal cut-off values were DOEE60≥17.75 min in NPTR, compared to other parameters regardless of AVSS or NPTR (P<0.05). When predicting which patients would be cured, the AUC of AVSS was superior to NPTR parameters (0.77~0.81 vs 0.61~0.76), and the determined best diagnostic cut-off values were DOEE≥4.125min in AVSS, compared to other parameters regardless of AVSS or NPTR (P < 0.05).

CONCLUSION

Rigiscan was able to predict the efficacy of daily tadalafil accurately and efficiently. Its diagnostic value was at maximum when DOEE60 ≥17.75 min of NPTR in tadalafil responders and DOEE ≥ 4.125 min of AVSS in cured patients.

Erectile Dysfunction in Type-2 Diabetes Mellitus Patients: Predictors of Early Detection and Treatment

PURPOSE

To identify risk factors and potential predictors of erectile dysfunction (ED) in type-2 diabetes mellitus (T2DM) patients for early detection and treatment.

METHODS

A retrospective cohort was used to assess the clinical data of 105 diabetic patients with ED from May 2019 to April 2020 age-matched to 105 diabetic patients without ED. Potential risk factors that could contribute to ED were compared between the groups. Erectile function was evaluated using the International Index of Erectile Function-5 questionnaire.

RESULTS

There were higher rates of diabetic peripheral neuropathy (p = 0.036) and retinopathy (p < 0.001), longer duration of diabetes (p < 0.001), lower estimated glomerular filtration rate (p = 0.010) values, and higher uric acid (p < 0.001) and C-reactive protein (p = 0.001) levels in the ED group compared to the non-ED group. Multivariate logistic analysis identified uric acid, diabetic retinopathy, and T2DM course as independent predictors of diabetic ED. Diabetics with retinopathy and T2DM for ≥49 months were 3.028 and 3.860 times more likely to have ED, respectively. Uric acid values ≥392.5 μmol/L were associated with 18.638 times greater risk of having ED, though the values were within normal range.

CONCLUSION

In T2DM patients, higher uric acid (≥392.5 μmol/L), longer diabetes duration (≥49 months), and the presence of diabetic retinopathy were important and reliable predictors for diabetic ED. For patients who have high risk factors for developing ED, diligent screening and early treatment are necessary.

Nocturnal penile erections: A retrospective study of the role of RigiScan in predicting the response to sildenafil in erectile dysfunction patients

Sildenafil enhances the nitric oxide–cGMP pathway of erection, which is claimed to have a role in nocturnal penile tumescence and rigidity (NPTR). This study aimed to find whether RigiScan can predict the response to sildenafil among erectile dysfunction (ED) patients and to find which RigiScan parameter produces the best prediction. Medical records of 172 ED patients were revised regarding their full sexual history, standard andrology examination, NPTR monitoring by the RigiScan device, and the degree of response to sildenafil. Of 172 ED patients, 94 patients (54.7%) were sildenafil responders. All RigiScan parameters were higher in the sildenafil responder group. The RigiScan parameters with the most differentiating power between both sildenafil responders and non-responders were base rigidity (AUC 0.860) and then tip rigidity (AUC 0.831). The cut-off value of base and tip rigidity with the highest diagnostic accuracy was 42.5%. This finding was found to be more specific than the sensitivity in predicting a positive response to sildenafil (85.9% vs. 70.2% and 92.3% vs. 59.6%, for base and tip rigidity, respectively). Sildenafil response in ED cases can be predicted through NPTR monitoring using the RigiScan device and ED patients with RigiScan base or tip rigidity less than 42% are not expected to respond well to sildenafil.

The "Kiel Concept" of Long-Term Administration of Daily Low-Dose Sildenafil Initiated in the Immediate Post-Prostatectomy Period: Evaluation and Comparison With the International Literature on Penile Rehabilitation

INTRODUCTION

Radical prostatectomy (RP) is the most common definitive invasive treatment option for localized prostate cancer. Although the different surgical procedures-open RP, laparoscopic RP, and robot-assisted laparoscopic RP-do not differ significantly for the results of postoperative erectile dysfunction (ED) and continence, the fear of losing erectile function (EF) is often an important factor for preoperatively sexually active men when deciding for or against a procedure.

AIM

To review the available literature on rehabilitation of EF after RP and to evaluate the value of the "Kiel concept" against different strategies of phosphodiesterase type 5 inhibitor (PDE5i) low-dose treatments.

METHODS

A review of the available literature up to January 2017 was undertaken using the key terms postsurgical ED, penile rehabilitation," PDE5i rehabilitation, and PDE5i daily dose treatment.

MAIN OUTCOME MEASURES

As a main outcome measure we chose reviewed different concepts on the rehabilitation of EF after RP, taking into account the clinical background of the Kiel concept.

RESULTS

The different therapeutic concepts for rehabilitation of EF after nerve-sparing RP are surprising. The most frequently applied method is application of different PDE5is. Despite different studies on efficacy, the issue of an optimal concept remains unresolved. The reason for this, among others, can be found in the difficulty of comparing different studies, which can vary with respect to the degree of nerve sparing, postoperative preservation of nocturnal erections, concomitant morbidity, and the number and experience of surgeons.

CONCLUSION

In 86% of patients, the Kiel concept has been shown to support rehabilitation of EF after nerve-sparing RP with some form of therapeutic method. The Kiel concept is one therapeutic option among other comparable therapeutic options. Osmonov DK, Jünemann KP, Bannowsky A. The "Kiel Concept" of Long-Term Administration of Daily Low-Dose Sildenafil Initiated in the Immediate Post-Prostatectomy Period: Evaluation and Comparison With the International Literature on Penile Rehabilitation. Sex Med Rev 2017;5:387-392.

Effect of daily sildenafil on patients with absent nocturnal erections due to pelvic fracture urethral disruption: a single-centre experience

Erectile dysfunction (ED) is a common sequel of pelvic fracture urethral disruption. Those patients with nocturnal erections may respond favourably to sildenafil; however, little is known about the response to sildenafil in patients with absent nocturnal erections. The aim was to evaluate the response to the treatment of sildenafil 50 mg taken once daily in the patients with absent nocturnal erections. From January 2008 to December 2011, a total of 28 patients with absent nocturnal erections were evaluated. We recorded nocturnal penile tumescence and rigidity with an erectometer. If nocturnal erections were absent for three nights, patients were administrated sildenafil 100 mg at bedtime and tested again at the fourth night. Penile duplex ultrasound with intracavernous injection was performed to define the cause of ED. All patients received a daily dose of sildenafil 50 mg for 12 weeks. Response to sildenafil treatment was defined as sustained erections allowing vaginal penetration and intercourse. Twenty-three (78%) patients completed the daily sildenafil treatment, and follow-up was available. The nocturnal erections at the fourth night in 13 patients (46.4%) were improved. About 61.5% (8/13) reported effective response to daily sildenafil. The improvement of nocturnal erections induced by sildenafil taken at bedtime might predict the response to sildenafil taken daily.

Development of UK recommendations on treatment for post-surgical erectile dysfunction

AIM

To develop a management strategy (rehabilitation programme) for postsurgical erectile dysfunction (ED) among men experiencing ED associated with treatment of prostate, bladder or rectal cancer that is suitable for use in a UK NHS healthcare context.

METHODS

PubMed literature searches of ED management together with a survey of 13 experts in the management of ED from across the UK were conducted.

RESULTS

Data from 37 articles and completed questionnaires were collated. The results discussed in this study demonstrate improved objective and subjective clinical outcomes for physical parameters, sexual satisfaction, and rates of both spontaneous erections and those associated with ED treatment strategies.

CONCLUSION

Based on the literature and survey analysis, recommendations are proposed for the standardisation of management strategies employed for postsurgical ED.

A phase II, single-blind, randomized, crossover evaluation of the safety and efficacy of avanafil using visual sexual stimulation in patients with mild to moderate erectile dysfunction

OBJECTIVE

To evaluate the safety, efficacy and time course of three doses of avanafil (50 mg, 100 mg and 200 mg) compared with sildenafil 50 mg or placebo, given in conjunction with visual sexual stimulation (VSS) videos in men with mild to moderate erectile dysfunction (ED).

PATIENTS AND METHODS

Male patients, 35-70 years of age, with mild to moderate ED of ≥6 months duration, were included in the study. During the course of the study, each patient received placebo, active control (sildenafil 50 mg), and one dose of avanafil (50 mg, 100 mg or 200 mg), all administered in random order at least 72 h apart. RigiScan® (Dacomed Corp., Minneapolis, MN, USA) monitoring was used in conjunction with 20-min VSS videos (20, 60, and 100 min after dosing) to determine the duration of and time to ≥60% penile rigidity, maximum rigidity, tumescent activity units (TAUs), rigidity activity units (RAUs), and responses to the five-point Erection Assessment Scale. Safety assessments included adverse events (AEs), vital sign changes in response to dosing, laboratory results (complete blood counts, chemistry panel, prostate-specific antigen, serum testosterone, prothrombin time and urine analysis) and physical examination findings.

RESULTS

Eighty-three patients were randomized and received at least one dose of study medication; 82 patients completed the study. Peak response to avanafil occurred in the early interval (20-40 min after dosing), while peak response to sildenafil occurred either in the middle (60-80 min) or late (100-120 min) intervals after dosing. Results were qualitatively similar for all other efficacy endpoints. During the 20-40-min interval, the majority of values for TAUs and RAUs with the avanafil 50-mg, 100-mg and 200-mg treatments were significantly superior to placebo (P < 0.05). Avanafil treatment was generally well tolerated; facial flushing (7-15%) was the most commonly observed AE, and no visual disturbances were reported.

CONCLUSION

A favourable safety profile and improvement in sexual function, coupled with rapid onset of action and durability of effect, make avanafil an attractive option for males with ED, especially in the setting of on-demand treatment.

Increasing the dose of vardenafil on a daily basis does not improve erectile function after unilateral nerve-sparing radical prostatectomy

INTRODUCTION

Several treatment regimens for rehabilitation of erectile function (EF) after nerve-sparing radical prostatectomy (nsRP) are currently discussed. The optimal and most cost-effective therapy is still not found yet.

AIM

To evaluate the effect of vardenafil, a PDE5 inhibitor, dose escalation on recovery of EF after unilateral nsRP.

METHODS

Thirty-six sexually active patients received a unilateral nsRP. All patients completed an International Index of Erectile Function-5 items (IIEF-5) questionnaire concerning EF preoperatively. Group 1 (N = 12 patients) received vardenafil 5 mg/day vs. group 2 (N = 12) who received vardenafil 10 mg/day at night beginning the day of catheter removal. A control of 12 patients underwent follow-up without PDE5 inhibitors.

MAIN OUTCOME MEASURE

The IIEF-5 was the primary end point. IIEF-5 questionnaires were completed at baseline, 3, 6, and 12 months after nsRP.

RESULTS

In group 1 (5 mg/day vardenafil) the IIEF-5 score decreased from a preoperative 22.4 mean score to 4.2 at 3 months, 8.9 at 6 months, and 13.4 mean score at 12 months after nsRP vs. preoperative 22.8, 4.1 at 3 months, 7.9 at 6 months, and 12.8 mean score at 12 months in group 2 (10 mg/day vardenafil). In the control group the preoperative IIEF-5 mean score of 21.9 decreased to 3.8 at 3 months, 6.1 at 6 months, and 8.9 at 12 months. Statistical evaluation showed significant difference in IIEF-5 score and time to recovery of EF between groups 1 and 3 and between groups 2 and 3 (P < 0.01). No statistical differences were found between groups 1 and 2.

CONCLUSIONS

Daily low-dose vardenafil lead to significant improvement of recovery of EF. In this study doubling the dosage did not improve the recovery of EF further.

[Counselling for erectile dysfunction during inpatient rehabilitation after radical prostatectomy]

For men erectile function is essential for quality of life. Besides urine incontinence postsurgical erectile dysfunction (ED) following radical prostatectomy (RPE) represents a significant and prevalent problem. One of the first approaches to this condition should be a consultation performed by professionals in a rehabilitation clinic.A total of 149 patients post RPE participated in this prospective study. All patients were questioned about their understanding of postoperative surgical ED after RPE and if affected they were asked about their own psychological burden as well as their knowledge of possible therapy options. The qualities of presurgical patient information as well as the modules of information pertaining to ED during the rehabilitation were evaluated. Of the patients, 53% expressed that they experienced a considerable burden due to postsurgical ED during their follow-up rehabilitation (AR group) and 70% of the patients during oncological rehabilitation treatment (rehab group). Men who were sexually more active prior to surgery suffered more from postsurgical ED than their less active counterparts. A negative correlation between psychological burden and age was found in the AR group, which however was levelled in the rehab group. Particularly in older patients the burden of ED increases with more time elapsing after the operation. The medical information on ED therapy options provided during the inpatient rehabilitation was considered to be essential by 60% of the men in the AR group and 48% of the patients in the rehab group.Therapeutic possibilities for postsurgical ED following RPE cannot always be given to patients in the preoperative phase or during their stay in the hospital. Since however a large majority of men suffer from postoperative ED following RPE a specialized inpatient urological rehabilitation is suited for a comprehensive consultation.

The effects of phosphodiesterase type 5 inhibitors on penile rigidity variables during a period with no sexual stimulation: a laboratory setting double-blind study

OBJECTIVE

To investigate the effects of phosphodiesterase type 5 (PDE5) inhibitors on erectile variables during a period with no sexual stimulation in a laboratory setting double-blind study.

PATIENTS AND METHODS

In all, 80 men without erectile dysfunction (ED) but with lifelong premature ejaculation (PE) were included in the study. The men were divided equally in to four groups and received either placebo, vardenafil (10 mg), sildenafil (50 mg) or tadalafil (20 mg) in a double-blind study design. The men attended the laboratory following 3 days of sexual abstinence and placebo or one of the PDE5 inhibitors was ingested after ≥ 2 h of fasting and non-smoking. The men were then immediately placed in a silent room and real-time penile rigidity and tumescence monitoring with Rigiscan Plus (Rigiscan Plus® System, Osbon Medical Systems, Augusta, GA, USA) began. The men read some magazines or newspapers that contained no sexually stimulating material for 1.5 h. There was no interaction between the men and observer during the test period. Times to first measured and total durations of base and tip rigidities, and also total and per minute rigidity were evaluated.

RESULTS

The recorded base and/or tip rigidity ratios were 40% (eight of 20), 71% (12/17), 47% (nine of 19) and 70% (14/20) in men who took placebo, sildenafil, tadalafil and vardenafil, respectively (P = 0.126). The ratio of men who could obtain ≥ 60% base and/or tip rigidities were 10% (two of 20), 41% (seven of 17), 26% (five of 19) and 55% (11/20) in placebo, sildenafil, tadalafil and vardenafil groups, respectively (P < 0.05). The median time to first measured base rigidity was 58.0, 21.5, 54.5 and 57 min with placebo, sildenafil, tadalafil and vardenafil, respectively (P = 0032). The median total duration of recorded base rigidity was 4.0, 27.5, 10.0 and 11.5 min in men who took placebo, sildenafil, tadalafil and vardenafil, respectively (P = 0.013). The median total base rigidity (area under the curve) was 72.8, 699.0, 360.5 and 553.0 with placebo, sildenafil, tadalafil and vardenafil, respectively (P = 0.016).

CONCLUSIONS

Significant penile rigidities were obtained with PDE5 inhibitors during the short test period, with no sexual stimulation, in laboratory conditions. This finding might support the use of PDE5 inhibitors in men who need penile rehabilitation.

Randomized, double-blind, placebo-controlled study of postoperative nightly sildenafil citrate for the prevention of erectile dysfunction after bilateral nerve-sparing radical prostatectomy

Four weeks after bilateral nerve-sparing radical retropubic prostatectomy, men with normal erectile function before surgery were randomized to double-blind sildenafil (50 or 100 mg) or placebo nightly for 36 weeks, followed by an 8-week drug-free period before assessment of erectile function. Enrollment was prematurely ceased and only 76 men completed because, assuming a placebo response rate similar to the published literature (for example, 34% in meta-analysis), the 25% response at blinded interim review suggested a lack of treatment effect. On the contrary, spontaneous erectile function (a combined score of >or=8 for questions 3 and 4 of the International Index of Erectile Function and a positive response to 'Were erections good enough for satisfactory sexual activity?') occurred in only 4% of the placebo group (n=1 of 25) versus 27% (n=14 of 51, P=0.0156, Fisher's exact test) of the sildenafil group. Nightly sildenafil administration for 36 weeks after surgery markedly increased the return of normal spontaneous erections.

Rehabilitation of erectile function following radical prostatectomy

The concept of muscle rehabilitation after nerve injury is not a novel idea and is practiced in many branches of medicine, including urology. Bladder rehabilitation after spinal cord injury is universally practiced. The erectile dysfunction (ED) experienced after radical prostatectomy (RP) is increasingly recognized as being primarily neurogenic followed by secondary penile smooth muscle (SM) changes. There is unfortunately no standard approach to penile rehabilitation after RP because controlled prospective human studies are not available. This article reviews the epidemiology, experimental pathophysiological models, rationale for penile rehabilitation, and currently published rehabilitation strategies.

[Is rehabilitation of erectile function following pelvic surgery reasonable? Review of the literature: from sports to PDE5 inhibitors]

Increasingly, urologists are seeing patients with erectile dysfunction after pelvic operations. In most cases, radical prostatectomy is the cause. Even when a nerve-sparing procedure is performed, approximately 50% of the patients suffer from erectile dysfunction. This report discusses the causes and theoretical therapies, including lifestyle changes, strategies for neuroregeneration and the associated prevention of apoptosis of the smooth muscle of the corpus cavernosum and improvement of the corpora cavernosa by increased oxygenation. According to the international literature, many of these agents and lifestyle modifications display promise for treating impotence. Early treatment for patients recovering from pelvic operations seems to be reasonable. It is assumed that the natural recovery of erections may take as long as 18 to 24 months postsurgery or even longer; however, treatment modalities may reduce the time to erectile recovery.

Recovery of erectile function after nerve-sparing radical prostatectomy: improvement with nightly low-dose sildenafil

OBJECTIVE

To evaluate the effect of low-dose sildenafil for rehabilitating erectile function after nerve-sparing radical prostatectomy (NSRP), as the delay to recovery of erectile function after NSRP remains under debate.

PATIENTS AND METHODS

Forty-three sexually active patients had a NSRP; at 7-14 days after surgery they had a Rigiscan (Dacomed Corporation, Minneapolis, MN, USA) measurement of nocturnal penile tumescence and rigidity (NPTR). To support the recovery of spontaneous erectile function, 23 patients with preserved nocturnal erections received sildenafil 25 mg/day at night. A control group of 18 patients were then followed but had no phosphodiesterase-5 inhibitors. The International Index of Erectile Function (IIEF)-5 questionnaire was completed 6, 12, 24, 36 and 52 weeks after NSRP.

RESULTS

Of the 43 patients, 41 (95%) had one to five erections during the first night after catheter removal. In the group using daily sildenafil the mean IIEF-5 score decreased from 20.8 before NSRP to 3.6, 3.8, 5.9, 9.6 and 14.1 at 6, 12, 24, 36 and 52 weeks after NSRP, respectively. In the control group the respective scores were 21.2, decreasing to 2.4, 3.8, 5.3, 6.4 and 9.3. There was a significant difference in IIEF-5 score and time to recovery of erectile function between the groups (P < 0.001), with potency rates of 86% vs 66%.

CONCLUSION

The measurement of NPTR after NSRP showed erectile function even the 'first' night after catheter removal. In cases of early penile erection, daily low-dose sildenafil leads to a significant improvement in the recovery of erectile function.

Long-term treatment of erectile dysfunction with a phosphodiesterase-5 inhibitor and dose optimization based on nocturnal penile tumescence

OBJECTIVE

To test the hypothesis that a variable dosage of the oral phosphodiesterase type 5 (PDE5) inhibitor sildenafil (25, 50, 100 mg) or vardenafil (5, 10, 25 mg) determined according to results obtained from nocturnal penile tumescence and rigidity (NPTR, RigiScan), given nightly for 1 year, can improve spontaneous erectile function (EF) in men with mild-to-moderate arteriogenic erectile dysfunction (ED); this regimen was compared with a fixed daily dosage of sildenafil 25 mg or vardenafil 5 mg.

PATIENTS AND METHODS

In a prospective open-label, parallel-group trial 154 men with ED were randomized either to fixed low-dose sildenafil 25 mg or vardenafil 5 mg (group 1) or to the lowest erectile dosage of sildenafil (25, 50 or 100 mg) or vardenafil (5, 10 or 20 mg) (group 2) provoking an erectile event as measured by NPTR nightly for 1 year. The EF domain of the International Index of Erectile Function (IIEF) was assessed before and 1 year after the beginning of treatment, and at 4 weeks after ending treatment.

RESULTS

After 1 year, 27 of 63 (64%) evaluable men in group 1 had an EF domain score in the normal range, vs 46 of 61 (75%) men in group 2. After the subsequent 4-week wash-out phase, both groups continued to have improved EF domain scores; 22 of 63 (35%) men in group 1 still had a score in the normal range, whereas 38 of 61 (62%) in group 2 had a normal score. The EF domain score in group 1 and 2 improved significantly after 1 year of treatment, from 13.6 to 18.9, and 15.1 to 23.9, respectively (P < 0.01). After the subsequent 4-week wash-out phase, men from both groups maintained this significant level of EF, at 17.1 and 22.4, respectively (P < 0.05).

CONCLUSION

Nightly PDE5-inhibitor treatment 1 year in a dosage determined by NPTR measurements results in better EF than giving a fixed dosage of sildenafil (25 mg) or vardenafil (5 mg). This improvement persisted for >4 weeks beyond the end of treatment. The results from this open-label, randomized trial warrant verification under double-blind, placebo-controlled conditions.

Chronic sildenafil in men with diabetes and erectile dysfunction

Erectile dysfunction frequently represents a neurovascular complication of diabetes mellitus, and it has been calculated that almost 50% of diabetic men will have erectile dysfunction within 6 years after diagnosis. Penile endothelial and smooth muscle cell dysfunction are due to molecular pathway abnormalities (i.e., activation of PKC, increased oxidative stress and overproduction of advanced-glycosylation end products). The response rate to oral drug therapies, such as sildenafil, is lower than in most other groups. Because therapeutic alternatives (i.e., intracavernous injections with vasoactive agents) are not curative, clinical trials aimed to demonstrate rehabilitative effects with daily phosphodiesterase type-5 inhibitors are ongoing. If this approach proves successful, it will determine many advantages over the intracavernosal treatment and potentially induce sexual rehabilitation.

Penile rehabilitation after radical prostatectomy: where do we stand and where are we going?

INTRODUCTION

Postprostatectomy erectile dysfunction (ED) remains a serious quality-of-life issue. Recent advances in the understanding of the mechanism of postprostatectomy ED have stimulated great attention toward penile rehabilitation.

AIM

This review presents and analyzes a contemporary series of the recent medical literature pertaining to penile rehabilitation therapy after radical prostatectomy (RP).

MAIN OUTCOME MEASURES

The laboratory and clinical studies related to penile rehabilitation are analyzed. The validity of the methodology and the conclusion of the findings from each study are determined.

METHODS

The published and presented reports dealing with penile rehabilitation following RP in human and cavernous nerve injury in animal models are reviewed.

RESULTS

Exciting scientific discoveries have improved our understanding of postprostatectomy ED at the molecular level. The rationale for postprostatectomy penile rehabilitation appears to be logical according to animal studies. However, clinical studies have not consistently replicated the beneficial effects found in the laboratory studies. Currently available clinical studies are flawed due to short-term follow-up, small number of patients in the studies, studies with retrospective nature, or prospective studies without control. Rehabilitation programs are also facing a challenge with the compliance, which is critical for success for any rehabilitation program. At the present time, we do not have concrete evidence to recommend what, when, how long, and how often a particular penile rehabilitative therapy can be used effectively.

CONCLUSIONS

Large prospective, multicentered, placebo-controlled trials with adequate follow-up are necessary to determine the cost-effective and therapeutic benefits of particular penile rehabilitative therapy or therapies in patients following the treatment of clinically localized prostate cancer. Until such evidence is available, it is difficult to recommend any particular penile rehabilitation program as a standard of practice.

Management of erectile dysfunction after radical prostatectomy in 2007

As radical prostatectomy (RP) remains a commonly used procedure in the treatment of clinically localized prostate cancer, we critically analyzed the evidence suggesting the role of pharmacological prophylaxis and treatment of erectile dysfunction (ED) after surgery. Systematic literature review using Medline and Cancerlit from January 1997 to December 2006. Abstracts published in the journals European Urology, The Journal of Urology, The International Journal of Impotence Research and The Journal of Sexual Medicine as official proceedings of internationally known scientific Societies held in the same time period were also assessed. Patient selection and surgical technique (i.e., preservation of neurovascular bundles) are the major determinants of post-operative erectile function. Pharmacological treatment of post-operative ED, using either oral or local approaches, is effective and safe. Moreover, recent studies have shown that pharmacological prophylaxis early after RP can significantly improve the rate of erectile function recovery after surgery. Use of on-demand treatments for treatment of ED in patients subjected to RP has been shown to be highly effective, especially in case of properly selected young patients treated with a bilateral nerve-sparing approach by experienced surgeons. In this context, pharmacological prophylaxis may potentially have a significant expanding role in future strategies aimed at preserving post-operative erectile function.

Improved spontaneous erectile function in men with mild-to-moderate arteriogenic erectile dysfunction treated with a nightly dose of sildenafil for one year: a randomized trial

AIM

To test the hypothesis that sildenafil (50 mg nightly for one year) can improve spontaneous erectile function (EF) in men with mild-to-moderate arteriogenic erectile dysfunction (ED) responsive to erectogenic treatment.

METHODS

In a prospective open-label trial, 112 men with ED were randomized to sildenafil 50 mg nightly or sildenafil 50 or 100 mg as needed for 12 months, followed by one-month and 6-month non-medicated periods. Non-randomized, non-medicated men with ED were also assessed. The EF domain of the International Index of Erectile Function (IIEF EF) and the peak systolic velocity (PSV) of penile cavernous arteries were used to measure the efficacy.

RESULTS

After sildenafil treatment and a subsequent non-medicated month, IIEF EF was normal in 29 of 48 (60.4%, 95% confidence interval [CI]: 45.3-74.2%) of the nightly group vs. 4 of 49 (8.2%, 95% CI: 2.3-19.6%) of the as-needed group. PSV improved by 11.2 cm/s (95% CI: 4.7-21.4; P=0.012) in the nightly group but only by 3.4 cm/s (-5.1-14.7; P=0.435) in the as-needed group. IIEF EF normalized in 1 of 18 (5.6%, 95% CI: 0.1-27.3%) non-medicated men and the PSV declined slightly. Six months after treatment, the IIEF EF remained normal and PSV was stabilized in most (28/29, 97%) nightly group men who had initially normalized.

CONCLUSION

Sildenafil nightly for one year resulted in ED regression that persisted well beyond the end of treatment, so that spontaneous EF was characterized as normal on the IIEF in most men. The results from this open-label, randomized trial warrant verification under double-blind, placebo-controlled conditions.

Relationship between chronic tadalafil administration and improvement of endothelial function in men with erectile dysfunction: a pilot study

Men with erectile dysfunction (ED) frequently have a disproportionate burden of comorbid vascular disorders including atherosclerotic disease. We investigated whether scheduled tadalafil is better than on-demand (OD) in improving endothelium-dependent vasodilatation of cavernous arteries in men with ED and whether this effect is also exerted on markers of endothelial function. We did an open-label, randomized, crossover study including 20 male outclinic patients aged 18 years or older (mean age 54 years) who had at least a 3-month history of ED of any severity or etiology. Tadalafil (20 mg) on alternate days (ADs) or OD was administered for 4 weeks. Primary end points were variations of basal inflow (peak systolic velocity (PSV)) and flow-mediated dilatation (FMD) of cavernous arteries compared with baseline at penile Duplex ultrasound. Secondary end points were variations of Q13-SIEDY scores regarding morning erections and of markers of endothelial function, that is, vascular cell adhesion molecule (VCAM), intercellular cell adhesion molecule, endothelin-1 (ET-1), insulin and C-reactive protein (CRP). PSVs and FMD were higher after AD treatment when compared with OD and baseline, respectively (P=0.0001), and improvements were maintained from 2 weeks after discontinuation (P<0.005). Patients receiving tadalafil AD experienced a significant improvement of morning erections as compared to AD treatment (P<0.0001); ET1, VCAM and CRP showed a robust decrease after chronic vs OD regimes (P<0.05), with concomitant increase in insulin levels (P<0.05), without any variation in blood pressure and other laboratory parameters. Chronic but not OD tadalafil improves endothelial function with sustained effects from its discontinuation. Chronic treatment also produces a dramatic increase in morning erections, which determines better oxygenation to the penis, thus providing a rationale for vascular rehabilitation.

Are consecutive nightly recordings required for valid evaluation of sleep-associated erections?

We questioned the need for more than one RigiScan recording for accurate assessment of sleep-associated penile erections and determine the necessity of consecutive nightly recordings for valid evaluation of sleep-associated erections. Men complaining of erectile dysfunction (ED) and referred to RigiScan evaluation for the first time participated. Recordings were performed at the patient's home during two consecutive nights, and data on test time, number of erections, erection duration, minimal and maximal base and tip tumescence and rigidity were retrieved for both nights. Normal erectile function was defined with the recording of at least one erection (70 out of 100% tip rigidity lasting for at least 10 min during either night). The main outcome measures were RigiScan recordings. Group 1 consisted of 29 men (mean age 42.4+/-13.8 years, range 22-71) who had normal erections, all during the first night. Group 2 consisted of 26 men (mean age 48.6+/-13.5 years, range 25-70) who failed to fulfill both criteria for normal erection. In Group 2, only the values for penile base rigidity and erection duration were normal during the first night: the parameters of maximal base tumescence, tip rigidity, number of effective erections and duration of effective erections that were impaired during the first night were significantly worse (P<0.01) during the second night. The required information for the diagnosis of psychogenic ED was obtained during the first night in >50% of the participants. Men with normal erections during the first night can be spared the inconvenience and cost of re-testing. Consecutive night recording should be reserved for patients whose recorded data during the first night did not fulfill the criteria for normal erection.

Can Phosphodiesterase Type 5 Inhibitors Cure Erectile Dysfunction?

INTRODUCTION AND OBJECTIVES

To systematically analyze and review the available evidence about the potential role of chronic administration of phosphodiesterase type 5 (PDE-5) inhibitors for the cure of erectile dysfunction (ED) based on clinical and basic science data.

METHODS

Analysis of published full-length papers that were identified with Medline and Cancerlit from January 1993 to September 2005. Abstracts published in the journals European Urology, the Journal of Urology, the International Journal of Impotence Research, and the Journal of Sexual Medicine as official proceedings of internationally known scientific societies held in the same time period were also assessed.

RESULTS

Chronic administration of PDE-5 inhibitors have reportedly been associated with increased persistent vascular and endothelial function--which represents a key factor in maintaining vascular tone and inducing vasodilation--by increasing the level of endothelial cGMP generated by activation of endothelial nitric oxide. Clinical studies have revealed a potential protective role of these compounds on endothelial function in short- and long-term assessments. Several studies based on animal models have provided direct experimental support for the role of PDE-5 inhibitors in improving the structure and function of the cavernosal tissue and have suggested potential molecular mechanisms involved.

CONCLUSIONS

Although evidence increasingly supports the potential role of chronic administration of PDE-5 inhibitors for improving erectile function in patients affected by ED, long-term data are lacking. However, data available from animal models support the evidence of potential benefits induced on endothelial function by chronic exposure to PDE-5 inhibitors.

Nocturnal Tumescence: A Parameter for Postoperative Erectile Integrity After Nerve Sparing Radical Prostatectomy

PURPOSE

The exact process and time required for rehabilitation of erectile function after nerve sparing prostatectomy remain unclear to date. Different theories of the pathophysiology of postoperative erectile dysfunction are currently being discussed. In a prospective study we performed recordings of nocturnal penile tumescence and rigidity during the acute phase after nerve sparing radical prostatectomy, ie in the first night after removal of the catheter, to assess the organic penile integrity.

MATERIALS AND METHODS

In 27 patients with local prostate carcinoma who had been sexually active before the intervention, we performed unilateral or bilateral nerve sparing radical prostatectomy. Preoperative sexual function of all patients was evaluated by the International Index of Erectile Function-5 questionnaire. On the day of catheter removal (postoperative day 7 to 14) an NPTR recording was performed on the following night with an erectometer (RigiScan).

RESULTS

All patients had a preoperative IIEF score greater than 18. After removal of the catheter 25 of 27 patients (93%) showed 1 to 5 nocturnal rigidity increases by greater than 70% for at least 10 minutes. In a control group of 4 patients who underwent radical prostatectomy without nerve sparing, no nocturnal erections were recorded.

CONCLUSIONS

NPTR recording during the acute phase after nerve sparing radical prostatectomy showed residual erectile function as early as the first night after catheter removal. These results are significant for selecting adequate pharmacological treatment for optimal therapy and rehabilitation of satisfactory erections and sexual function. In cases of early nocturnal tumescence, application of a PDE5 inhibitor can support successive organ rehabilitation. However, if tumescence does not occur, penile injection therapy is recommended.

Nitric oxide/redox-based signalling as a therapeutic target for penile disorders

Oxidative and/or nitrosative stress is implicated in the pathogeneses of assorted penile disorders of clinical significance, notably erectile dysfunction, priapism and penile fibrosis. It is becoming increasingly recognised that the generation and activity of reactive oxygen and nitrogen species in the penis influence vascular homeostasis of this organ, with adverse effects exerted at cellular and molecular levels. Furthermore, these elements may interact with molecular signalling pathways operating in the penis, modulating their functional roles. This interaction in particular suggests that by accessing molecular targets associated with oxidative/nitrosative stress in the penis, new pharmacotherapeutic approaches may be developed to promote normal erectile ability and preserve erectile tissue health. This notion pertains to, but also extends beyond, interventions which predictably target components of the nitric oxide-based signal transduction pathway for the on-demand treatment of erectile dysfunction. The next line of pharmaceuticals for disorders of the penis, in general, may well spawn from an integrative understanding of the complex regulatory interactions influenced by, as well as influencing nitric oxide signalling in this organ.

Update on erectile dysfunction in prostate cancer patients

PURPOSE OF REVIEW

Evolution in the management of prostate cancer includes increased attention being paid to patient quality of life after treatment, specifically with issues related to sexual function. Erectile dysfunction is one of the major concerns of patients undergoing treatment for prostate cancer. There are several recognized factors that determine the postoperative incidence of erectile difficulties, including patient age, degree of cavernosal nerve sparing during surgery, cancer stage, and associated vascular comorbidities. Early initiation of rehabilitation protocols after radical prostatectomy has been advocated to promote the speed and degree of recovery of erectile function. The aim of this communication is to review recent initiatives in erectile dysfunction restoration after prostate cancer therapy.

RECENT FINDINGS

In recognition of the neurogenic basis of erectile dysfunction after radical prostatectomy, new strategies have been devised to initiate the rehabilitation process. Type 5 phosphodiesterase inhibitors, vacuum erection devices, and intracavernosal and intraurethral application of vasoactive agents have all been reported in a positive light in recent studies. Developments in cavernous nerve graft interposition procedures, perioperative neuroprotection measures, and postoperative neurotrophic treatments aim to preserve prostate cancer patients' qualities of life.

SUMMARY

Data generated from a number of clinical investigations document that pharmacologic rehabilitation programs provide a higher rate of recovery of erectile function following radical prostatectomy. Both intracavernosal and intraurethral applications of vasoactive agents and vacuum devices can speed the recovery period for return of erectile function. Various neuroprotective and neurotrophic approaches are thought to provide integral roles for the maintenance of sexual function in men undergoing prostate cancer therapy.

Does sildenafil enhance quality of nocturnal erections in healthy young men? A NPT-RigiScan study

OBJECTIVE

To assess the effect of sildenafil on nocturnal erectile function (EF) in young healthy volunteers with normal sexual function (SF) according to the International Index of Erectile Function (IIEF) questionnaire.

METHODS

Thirty-three young (mean age 21 +/- 0.3 years; range 18-25) healthy volunteers not taking any medications who had normal SF and an EF domain >26 on the IIEF questionnaire were evaluated. Erectile function was assessed using the RigiScan (Dacomed Corp., MN, USA) during three nights: night 1 = adaptation to the NPT-Rigiscan apparatus, night 2 = baseline recording of eight parameters, and night 3 = recordings after ingestion of sildenafil 100 mg. Data on the number of erections, erection duration, minimal and maximal base tumescence, minimal and maximal tip tumescence, and base and tip rigidity were analysed using anova with repeated measures.

RESULTS

A statistically significant improvement in all eight parameters was observed as a result of sildenafil administration: number of erections from 3.1 +/- 0.7 to 4.0 +/- 0.7 (P < 0.05), erection time 22 +/- 3.5 to 34.2 +/- 5.9, minimal base tumescence 8.2 +/- 0.8 to 8.7 +/- 0.8, maximal base tumescence 12.1 +/- 0.7 to 14.2 +/- 0.7, base rigidity 75.6 +/- 3.1 to 81.6 +/- 3.6, tip rigidity 70.6 +/- 1.5 to 75.9 +/- 3.1, minimal tip tumescence 5.9 +/- 0.5 to 6.5 +/- 0.6, and maximal tip tumescence 8.6 +/- 0.6 to 11.7 +/- 0.7 (P < 0.0001 for each of the last seven parameters). The mean sleep duration, 7.3 hours (range 6.30-9.20 hours), was similar for both nights of recording.

CONCLUSIONS

Sildenafil increases the quality and number of nocturnal erections as tested by the NPT-RigiScan in young healthy volunteers with normal EF.

Characteristics of sildenafil erections in healthy young men

AIM

To determine the effect of sildenafil citrate on the nocturnal penile erections (i.e. time to onset, the duration of erection, and the interval between first and second erections) of healthy young men.

METHODS

Twenty-two potent men, 23-29 years old, were recruited for the study. All subjects completed three sessions over consecutive nights using the RigiScan monitoring device (Dacomed, Minneapolis, USA). After a first night of adaptation, night 2 records were their baseline values, and on night 3 they received 100 mg of sildenafil citrate. Statistical comparisons were done between the second and third night data.

RESULTS

The mean time to onset of the first erection with sildenafil citrate was (34+/-18) min, whereas it was (74+/-24) min (P 0.0001) without sildenafil citrate. The number of erections observed during the first 5 h after sildenafil citrate medication was 3.6+/-0.5 in contrast to 2.4+/-0.5 with no medication (P=0.001). The interval between first and second erections was shorter with sildenafil citrate: (52+/-26) min vs. (85+/-34) min (P = 0.01). The duration of the last erection was statistically significantly longer with the sildenafil citrate: (64 +/-33) min vs. (42 +/-28) min (P 0.001).

CONCLUSION

Healthy young men achieved erection within 34 min after sildenafil citrate administration, which is shorter than the 1 h interval proposed by the manufacturer. The interval between the first and second erections was shorter and the duration of the last nocturnal erection was longer.

Erectile dysfunction and treatment of carcinoma of the prostate

Prostate cancer is the leading malignancy in men in the United States and causes more than 60,000 deaths annually. Treatment of prostate cancer, whether it be with surgery, radiation therapy, cryotherapy, or medical treatment, is associated with significant life-altering morbidity. Incontinence and erectile dysfunction (ED) too often are sequelae of these treatment alternatives. ED can be a significant complication and can alter the life of the patient with prostate cancer and his partner. Newer modifications of the radical prostatectomy with nerve-sparing techniques are the cornerstone of erection preservation. Time following radical prostatectomy has been shown to increase erectile function such that more patients have functional erections at 3 years than 1 year after surgery. With the advent of phosphodiesterase-5 (PDE-5) inhibitors, many men can have improved functional erections and return to active coitus. Prevention of ED also is an important management technique. Evidence is gathering that prophylaxis with regular vasoactive injection or daily PDE-5 agents may be an integral part of preservation of corpus cavernosum smooth muscle function. Combination medical therapy and surgical penile prosthesis implantation also are options for patients who do not respond to oral PDE-5 inhibitors.

Treating erectile dysfunction by endothelial rehabilitation with phosphodiesterase 5 inhibitors

A large body of evidence has accumulated demonstrating that a common pathway in conditions such as hypertension, atherosclerosis, hypercholesterolemia, diabetes mellitus, and erectile dysfunction (ED) is endothelial dysfunction. Although a complete pharmacological cure for ED is currently unavailable, the phosphodiesterase 5 (PDE5) inhibitors sildenafil, vardenafil, and tadalafil are efficacious oral therapy for ED. Results from recent studies suggest that regular treatment with a PDE5 inhibitor may lead to enhanced erectile function (EF) beyond that observed with on-demand usage, possibly through improvement of endothelial function. Such an effect may be viewed as rehabilitation of damaged erectile tissue. The present review focuses on several recent studies which provide evidence for the beneficial effect of regular PDE5 inhibitor administration on the improvement of EF by rehabilitation of vascular endothelium.

Testosterone and Sleep‐Related Erections: An Overview*

Sleep-related erections have been reported to occur from the intrauterine life to senescence. It has been speculated that the main function of nocturnal erections is to provide adequate engorgement of the corpora cavernosa, which then leads to increased tissue oxygenation. This is in turn to prevent cavernous fibrosis, the histopathological basis for corporeal venoocclusive dysfunction, which probably is the most common cause of organic erectile dysfunction. It has been suggested that sleep-related erections are triggered by the release of nitric oxide by the nitrergic nerve fibers within the cavernous nerves. Androgens regulate this mechanism as well as some other non-nitrergic processes within the corpora cavernosa and within the central nervous system. By contrast, the erectile response to tactile or visual erotic stimuli in wakefulness predominantly involves an androgen-independent system, although it may, at least to a certain degree, also be influenced by androgen-sensitive mechanisms. No doubt, androgens are key players in the physiology of nocturnal erections, and the availability of new, user-friendly testosterone preparations such as transdermal gel and intramuscularly administered testosterone undecanoate stimulates further investigations on this field. The prospect that the quality of sleep may also be improved by an androgen therapy administered to improve sleep-related erections in hypogonadal men needs further basic research and appropriate clinical studies.