Sildenafil Non-Responders: Haemodynamic and Morphometric Studies

Erectile dysfunction: role of computed tomography cavernosography in the diagnosis and treatment planning of venous leak

BACKGROUND

Venous leak appears to be the most common cause of vasculogenic erectile dysfunction (ED), which can be treated with venous embolization. Traditionally, conventional cavernosography was used for the diagnosis and treatment planning of venous leak. Recently, computed tomography (CT) cavernosography was introduced as a novel cross-sectional imaging method proposed to be advantageous over conventional cavernosography. We created a novel management algorithm for diagnosing venous leak including CT cavernosography as an imaging modality. In order to provide a broader basis for our management algorithm, a systematic literature review was conducted.

MAIN BODY

In this article we systematically review relevant literature on using CT cavernosography for the diagnosis and treatment planning in ED patients with venous leak following the PRISMA selection process. Nine full-text articles were included in the review and assigned a level of evidence grade (all grade II). Two studies (2/9) compared the results of conventional cavernosography with those of CT cavernosography which was superior for site-specific venous leak identification (19.4% vs. 100%, respectively). CT cavernosography is a more detailed imaging method that is faster to perform, exposes the patient to less radiation, and requires less contrast material. In one study (1/9), CT cavernosography was used for diagnostic purposes only. Eight studies (8/9) cover both, diagnostic imaging and treatment planning including embolization (1/9) and sclerotherapy (2/9) of venous leak in patients with venogenic ED. Three studies (3/9) describe anatomical venous leak classifications that were established based on CT cavernosography findings for accurate mapping of superficial and/or deep venous leak and identification of mixed or more complex forms of venous leak present in up to 84% of patients. In addition to treatment planning, one study (1/9) used CT cavernosography also for follow-up imaging post treatment.

CONCLUSION

CT cavernosography is superior to conventional cavernosography for diagnosis and treatment planning in patients with ED caused by venous leak (grade II levels of evidence). Consequently, CT cavernosography should be included in management algorithms for ED patients with suspected venous leak.

Long-Term Outcomes of Drug-Eluting Stent Implantation for Patients With Atherosclerotic Erectile Dysfunction not Responding to PDE-5-Inhibitors

PURPOSE

Endovascular therapy of erection-related arteries was shown to be a promising treatment option for patients with severe erectile dysfunction. Purpose of this study was to assess the longer-term safety and clinical success rate of endovascular revascularization of erection-related arteries with the Angiolite BTK stent in patients with arteriogenic erectile dysfunction.

MATERIALS AND METHODS

A total of 147 consecutive men (63.5±9.3 years) with erectile dysfunction due to 345 atherosclerotic lesions underwent endovascular revascularization. Patients received an International Index of Erectile Function (IIEF)-15 questionnaire at 30.3±7.2 months (follow-up [FU] period no less than 18 months) after stenting. An improvement by 4 points in the erectile function domain consisting of 6 questions (IIEF-6) was defined as minimal clinically important difference (MCID).

RESULTS

Technical success was achieved in 99% of lesions. One major adverse event occurred after endovascular revascularization. Sixty-eight (46%) patients completed their latest FU at least 18 months following the last intervention. Minimal clinically important difference was achieved in 54% (37/68) of patients.

CONCLUSIONS

In patients with arteriogenic erectile dysfunction not responding to phosphodiesterase-5-inhibitors (PDE-5-Is), endovascular therapy with a novel thin-strut sirolimus-eluting stent is a safe and effective treatment option during short- and longer-term FU.

CLINICAL IMPACT

Patients with severe erectile dysfunction profit greatly from endovascular therapy of erection-related arteries. Stable clinical outcomes are seen beyond a 1-year timeframe. It is proven that, the drug-eluting stent therapy for atherosclerotic ED in patients who have not responded to PDE-5-I therapy is safe and effective during longer-term follow-up.

Venous Leak Embolization in Patients with Venogenic Erectile Dysfunction via Deep Dorsal Penile Vein Access: Safety and Early Efficacy

PURPOSE

This all-comers registry aimed to assess safety and early efficacy of venous embolization in patients with venogenic erectile dysfunction due to venous leak in an unselected cohort.

METHODS

Between October 2019 and September 2022, patients with venogenic erectile dysfunction resistant to phosphodiesterase-5-inhibitors were treated with venous embolization using ultrasound-guided anterograde access via a deep dorsal penile vein in a single center. A mix of ethiodized oil and modified cyanoacrylate-based glue n-butyl 2 cyanoacrylate (NBCA) monomer plus methacryloxy-sulpholane monomer (Glubran-2, GEM, Italy) was used as liquid embolic agent. Prior to embolization, venous leak had been verified based on penile duplex sonography and computed tomography cavernosography. Procedural success was defined as technically successful and complete target vein embolization. The primary safety outcome measure was any major adverse event 6 weeks after the procedure. The primary feasibility outcome measure was IIEF-15 (International Index of Erectile Function-15) score improvement ≥ 4 points in ≥ 50% of subjects on 6 weeks follow-up post intervention.

RESULTS

Fifty consecutive patients (mean age 61.8 ± 10.0 years) with severe erectile dysfunction due to venous leak underwent venous embolization. Procedural success was achieved in 49/50 (98%) of patients with no major adverse events on follow-up. The primary feasibility outcome measure at 6 weeks was reached by 34/50 (68%) of patients.

CONCLUSION

Venous leak embolization via deep dorsal penile vein access using a liquid embolic agent was safe for all and efficacious in the majority of patients with severe venogenic erectile dysfunction on 6 weeks follow-up.

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.

Cavernous artery intima-media thickness predicts the response to sildenafil in erectile dysfunction patients as a morphological parameter

While the intima-media thickness (IMT) of the cavernous artery was used for diagnosis for vascular erectile dysfunction (ED) with more accuracy than the peak systolic velocity, the role of the IMT in predicting treatment responses remained unexamined. A total of 136 patients with ED were enrolled. The baseline clinical and laboratory characteristics were collected. Penile Doppler ultrasonography (PDU) was performed on all patients by a blinded sonographer. Sildenafil was administrated to all patients with an adjusted dose of 50 or 100 mg on demand over a period of 3 months. A follow-up was conducted on all patients using the Erectile Hardness Score (EHS) questionnaire along with the visual and tactile version of the standardised EHS tool. The peak systolic velocity (PSV) and IMT were compared between sildenafil responders and sildenafil nonresponders, while receiver operator characteristic (ROC) curves were used to calculate the cut-off values and compare the test power respectively. There was no statistical difference from the baseline characteristics. The IMT of cavernous artery was more accurate than PSV to predict the sildenafil response (AUC = 0.809, 0.626 respectively). IMT could predict sildenafil responders more accurately than PSV, and the cut-off value of the IMT of the cavernous artery was less than 0.22 mm.

Erectile Dysfunction Resistant to Medical Treatment Caused by Cavernovenous Leakage: An Innovative Surgical Approach Combining Pre-operative Work Up, Embolisation, and Open Surgery

OBJECTIVE

Thirty per cent of cases of erectile dysfunction (ED)/male impotence are resistant to oral treatment. Half of these cases are due to blood drainage from the corpora cavernosa occurring too soon, due to cavernovenous leakage (CVL). The aim of this study was to report on an innovative treatment scheme combining pre- and post-operative haemodynamic assessment, venous embolisation, and open surgery for drug resistant ED caused by CVL.

METHODS

An analysis of prospectively collected data, with clinical and haemodynamic pre- and post-operative assessment, was carried out. Forty-five consecutive patients operated on for drug resistant ED caused by CVL were evaluated pre-operatively and three months post-operatively by pharmacologically challenged penile duplex sonography (PC-PDS), pharmacologically challenged Erection Hardness Score (PC-EHS), and pharmacologically challenged computed caverno tomography (PC-CCT). Follow up consisted of patient interview, PC-PDS, PC-EHS and if needed PC-CCT.

RESULTS

Mean patient age was 43.9 ± 12.0 years (range 20-67). Forty-nine per cent of patients had primary ED. Patients with diabetes, a smoking habit, hypercholesterolaemia, and hypertension were 18%, 11%, 9%, and 4%, respectively. Three months post-operatively, PC-EHS increased from 2.0 ± 0.7 to 3.1 ± 0.74 (p < .001), with an EHS of 3 being the threshold allowing for penetration. Deep dorsal vein velocity, a haemodynamic marker of CVL, decreased from 14.2 ± 13.0 to 0.9 ± 3.5 cm/s (p < .001). After a 14.0 ± 10.7 month follow up, the primary success rate (clinical EHS ≥ 3, possible sexual intercourse with penetration, no vascular re-operation, no penile prosthesis implant) was 73.3%. Four patients (9%) underwent successful re-operation for persistent ED and CVL. Accordingly, compared with a possible penetration rate of 8.9% before surgery, 37 patients (secondary success rate: 82.2%) were able to achieve sexual intercourse with penetration. Type of ED (primary vs. secondary) and diabetes had no influence on the results. Thirty-two per cent of patients with secondary success achieved penetration with no medication.

CONCLUSIONS

After a 14 month follow up, pre-operative work up, embolisation, and open surgery during the same procedure allowed patients with ED resistant to oral medical to achieve intercourse with penetration.

Effect of Genetic Polymorphism on the Response to PDE5 Inhibitors in Patients With Erectile Dysfunction: A Systematic Review and a Critical Appraisal

INTRODUCTION

Several treatment strategies are nowadays available for erectile dysfunction (ED) patients. Currently, oral phosphodiesterase type 5 inhibitors (PDE5Is) are the first-line therapy for ED. However, they are effective in all treated cases with variable non-responsiveness. Many factors have been listed for this behavior, but the possibility of gene polymorphisms as an underlying cause has not been systematically investigated.

OBJECTIVES

This review aimed to assess the possible involvement of gene polymorphisms affecting the response to PDE5Is in men with ED.

METHODS

A systematic review was conducted based on a search of all relevant articles in various electronic sites such as PubMed, Medline Medical Subject Headings, Cochrane Library, Science Direct, Scopus, Embase, CINAHL, and Egyptian Knowledge Bank databases. Keywords used for relevant associations were sexual health, genes, variants, erectile dysfunction, polymorphisms, PDE5Is, and cavernous tissues.

RESULTS

Several studies have been carried out to determine the contribution of different encoded genes to ascertain the association between different genotypes and ED men who were non-responders for PDE5Is. 11 studies were selected for this review. In these studies, 6 investigated eNOS genetic polymorphism with variable outcomes. Only 1 study was carried out for each of the following genetic polymorphisms: phosphodiestrase 5A, G-protein β3 subunit, angiotensin converting enzyme, dimethylarginine dimethylaminohydrolase, arginase, and vascular endothelial growth factor with variable results.

CONCLUSION

Despite the relative shortage of available studies and the varied methodologies used, most of the research articles demonstrated a significant association between genetic polymorphism and the response to PDE5Is, especially for endothelial nitric oxide synthase polymorphism. The limited number of studies that investigated the possible effect of genetic polymorphism and the response to PDE5Is are challenged by many factors, particularly for the definition of responders and non-responders. This should be a motivating factor for researchers to perform further studies with a standardized methodology to address the influence of genetic variations on the response to PDE5Is. Mostafa T, Hassan A, Alghobary MF, et al. Effect of Genetic Polymorphism on the Response to PDE5 Inhibitors in Patients With Erectile Dysfunction: A Systematic Review and a Critical Appraisal. J Sex Med 2020;8:573-585.

Functional reconstruction of injured corpus cavernosa using 3D-printed hydrogel scaffolds seeded with HIF-1α-expressing stem cells

Injury of corpus cavernosa results in erectile dysfunction, but its treatment has been very difficult. Here we construct heparin-coated 3D-printed hydrogel scaffolds seeded with hypoxia inducible factor-1α (HIF-1α)-mutated muscle-derived stem cells (MDSCs) to develop bioengineered vascularized corpora. HIF-1α-mutated MDSCs significantly secrete various angiogenic factors in MDSCs regardless of hypoxia or normoxia. The biodegradable scaffolds, along with MDSCs, are implanted into corpus cavernosa defects in a rabbit model to show good histocompatibility with no immunological rejection, support vascularized tissue ingrowth, and promote neovascularisation to repair the defects. Evaluation of morphology, intracavernosal pressure, elasticity and shrinkage of repaired cavernous tissue prove that the bioengineered corpora scaffolds repair the defects and recover penile erectile and ejaculation function successfully. The function recovery restores the reproductive capability of the injured male rabbits. Our work demonstrates that the 3D-printed hydrogels with angiogenic cells hold great promise for penile reconstruction to restore reproductive capability of males.

Injury of corpus cavernosa results in erectile dysfunction, and repair leading to restoration of function is difficult. Here the authors construct 3D printed hydrogel constructs seeded with HIF-1α-expressing muscle derived stem cells to restore corpus function in a rabbit model.

Serum L-carnitine and vitamin D levels may be low among oral sildenafil citrate non-responders

This cross-sectional comparative study aimed to compare serum L-carnitine and 25(OH)D levels between men with ED non-responding for oral sildenafil citrate and healthy volunteers. Overall, 192 men, recruited from two University Hospitals, were allocated into two equal groups of matched age; healthy potent men and men with ED non-responders for oral sildenafil citrate. Oral sildenafil citrate non-responders self-reported inadequate erectile responses after four attempts using 100 mg with the manufacturer's guidelines relative to meals, associated medications, and sexual stimulation/arousal. Exclusion criteria were: diabetes, cardiovascular disorders, beta blockers treatment, morbid obesity, thyroid disorders, post-radical prostatectomy, and hepatic/renal failure. All participants were subjected to; history taking, clinical examination, validated IIEF-5 questionnaire, estimation of serum L-carnitine by calorimetric method and serum 25(OH)D by ELISA method. Compared with potent controls, ED men non-responders for oral sildenafil citrate showed significant decreases in the mean serum L-carnitine level (16.8 ± 3.6 uM/L versus 66.3 ± 11.9 uM/L, P = 0.001), the mean serum 25(OH)D level (21.2 ± 7.1 ng/ml versus 54.6 ± 7.9 ng/mL, P = 0.001) and IIEF-5 score (7.8 ± 2.6 versus 23.9 ± 1.3). Serum L-carnitine showed significant positive correlation with IIEF-5 scores (r = 0.873, P = 001), serum 25(OH)D (r = 0.796, P = 0.001) and significant negative correlation with the age (r = -0.515, P = 0.001). Serum 25(OH)D showed significant positive correlation with IIEF-5 scores (r = 0.855, P = 0.001) and significant negative correlation with the age (r = -0.223, P = 0.005). It is concluded that normal homeostasis of serum L-carnitine and 25(OH)D play a role in male sexual health being significantly decreased in ED non-responding for oral sildenafil citrate.

Multiple PDE5Is use as a marker of decreased overall men's health: A real-life study

Erectile dysfunction (ED) is considered a sentinel marker for poor general men’s health status. Severe ED has been associated with poor response to phosphodiesterase type 5 inhibitors (PDE5Is) therapy. We sought to assess the association of multiple PDE5Is prescription with the overall patients’ health status. Socio-demographic and clinical variables from 939 consecutive white–European, heterosexual, sexually-active men seeking medical help for ED at same tertiary-referral academic outpatient clinic were analyzed. Health-significant comorbidities were scored with the Charlson Comorbidity Index (CCI). Patients have been stratified into naïve and non-naïve according to their history of previous prescriptions of any PDE5I. Every patient completed the International Index of Erectile Function (IIEF) questionnaire. Logistic regression models tested the association between patients’ baseline characteristics (thus including previous PDE5Is prescriptions) and the overall health status. Overall, 328 (35%) patients were non-naïve for PDE5Is. Of them, 172 (52%), 99 (30%), and 57 (17%) had been prescribed with 1, 2 or 3 different PDE5Is, respectively. Naïve and non-naïve patients did not differ in terms of age, BMI, baseline ED severity; conversely, non-naïve patients had a higher CCI score. At logistic MVA, the number of PDE5Is prescriptions emerged as an independent predictor of a higher burden of comorbidities regardless of ED severity; the higher the number of PDE5Is prescriptions, the higher the CCI score (OR 1.69, 2.49, and 2.90 for 1, 2 or 3 previous PDE5Is, respectively), after accounting for age, BMI, baseline ED severity and cigarette smoking. More than a third of patients seeking medical help for ED at a single tertiary-referral center were non-naïve for PDE5Is. The increasing number of previous prescriptions of PDE5Is emerged as a worrisome marker of a poorer overall men’s health status regardless of ED severity.

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.

Intracavernous Injections of Bone Marrow Mononucleated Cells for Postradical Prostatectomy Erectile Dysfunction: Final Results of the INSTIN Clinical Trial

We recently reported stage I of a phase 1/2 clinical trial of cell therapy to treat postradical prostatectomy erectile dysfunction (INSTIN, INtra-cavernous STem-cell INjection clinical trial, NCT01089387). In this first stage, four doses of intracavernous autologous bone marrow mononuclear cells (BM-MNCs) were tested in 12 patients. Here, we report the results of stage II, in which six additional patients received the optimal dose identified in stage I (10⁹ BM-MNCs), and the long-term results in the 12 patients included in stage I. The objectives were to assess the safety and efficacy of this new treatment. In stage II, no patients had side effects, and the erectile function improvements were similar to those seen in stage I: after 6 months, significant improvements versus baseline were noted in International Index of Erectile Function-15 intercourse satisfaction (7.8±3.1 vs 2.2±3.4, p=0.033) and erectile function (18±8.3 vs 3.7±4.1, p=0.035) domains. In stage I patients, after a mean follow-up of 62.1±11.7 mo, there were no prostate cancer recurrences, and erectile function scores were somewhat lower compared with the 1-yr time point. These findings suggest that intracavernous BM-MNC injections are safe and improve erectile function. The decline in erectile function over time suggests a need for assessing repeated injections.

PATIENT SUMMARY

We report a phase 1/2 pilot clinical trial of cell therapy consisting in intracavernous injection of bone marrow mononuclear cells to treat postradical prostatectomy erectile dysfunction. Erectile function was improved after 6 mo in the patients given 1×10⁹ cells. No serious side effects (life threatening or requiring hospitalisation) occurred after a mean follow-up of 62.1 mo in the first 12 patients.

Safety of Intracavernous Bone Marrow-Mononuclear Cells for Postradical Prostatectomy Erectile Dysfunction: An Open Dose-Escalation Pilot Study

Evidence from animal models replicating postradical prostatectomy erectile dysfunction (pRP-ED) suggests intracavernous injection of bone marrow-mononuclear cells (BM-MNCs) as a promising treatment approach for pRP-ED. We conducted a phase 1/2 pilot clinical trial of intracavernous autologous BM-MNC injection to treat pRP-ED (NCT01089387). Twelve patients with localized prostate cancer and vasculogenic pRP-ED refractory to maximal medical treatment were divided into four equal groups treated with escalating BM-MNC doses (2×10(7), 2×10(8), 1×10(9), 2×10(9)). Tolerance was the primary endpoint. Secondary endpoints were the effects on erectile function and penile vascularization at 6 mo, as assessed using the International Index of Erectile Function-15 and Erection Hardness Scale questionnaires, and color duplex Doppler ultrasound. We measured the peak systolic velocity in cavernous arteries and assessed endothelial function using the penile nitric oxide release test. No serious side effects occurred. At 6 mo versus baseline, significant improvements of intercourse satisfaction (6.8±3.6, 3.9±2.5, p=0.044) and erectile function (17.4±8.9, 7.3±4.5, p=0.006) domains of the International Index of Erectile Function-15 and Erection Hardness Scale (2.6±1.1, 1.3±0.8, p=0.008) were observed in the total population. Spontaneous erections showed significantly greater improvement with the higher doses. Clinical benefits were associated with improvement of peak systolic velocity and of % penile nitric oxide release test and sustained after 1 yr. Our results need to be confirmed by phase 2 clinical trials.

PATIENT SUMMARY

We report a phase 1/2 pilot clinical trial investigating cell therapy with injection of bone marrow mononucleated cells to treat postradical prostatectomy erectile dysfunction. No serious side effects occurred. Improvements of erectile function and penile vascularization were noted. Further studies are required to confirm these preliminary results.

SOP conservative (medical and mechanical) treatment of erectile dysfunction

INTRODUCTION

Erectile dysfunction (ED) is the most frequently treated male sexual dysfunction worldwide. ED is a chronic condition that exerts a negative impact on male self-esteem and nearly all life domains including interpersonal, family, and business relationships.

AIM

The aim of this study is to provide an updated overview on currently used and available conservative treatment options for ED with a special focus on their efficacy, tolerability, safety, merits, and limitations including the role of combination therapies for monotherapy failures.

METHODS

The methods used were PubMed and MEDLINE searches using the following keywords: ED, phosphodiesterase type 5 (PDE5) inhibitors, oral drug therapy, intracavernosal injection therapy, transurethral therapy, topical therapy, and vacuum-erection therapy/constriction devices. Additionally, expert opinions by the authors of this article are included.

RESULTS

Level 1 evidence exists that changes in sedentary lifestyle with weight loss and optimal treatment of concomitant diseases/risk factors (e.g., diabetes, hypertension, and dyslipidemia) can either improve ED or add to the efficacy of ED-specific therapies, e.g., PDE5 inhibitors. Level 1 evidence also exists that treatment of hypogonadism with total testosterone < 300 ng/dL (10.4 nmol/L) can either improve ED or add to the efficacy of PDE5 inhibitors. There is level 1 evidence regarding the efficacy and safety of the following monotherapies in a spectrum-wide range of ED populations: PDE5 inhibitors, intracavernosal injection therapy with prostaglandin E1 (PGE1, synonymous alprostadil) or vasoactive intestinal peptide (VIP)/phentolamine, and transurethral PGE1 therapy. There is level 2 evidence regarding the efficacy and safety of the following ED treatments: vacuum-erection therapy in a wide range of ED populations, oral L-arginine (3-5 g), topical PGE1 in special ED populations, intracavernosal injection therapy with papaverine/phentolamine (bimix), or papaverine/phentolamine/PGE1 (trimix) combination mixtures. There is level 3 evidence regarding the efficacy and safety of oral yohimbine in nonorganic ED. There is level 3 evidence that combination therapies of PDE5 inhibitors + either transurethral or intracavernosal injection therapy generate better efficacy rates than either monotherapy alone. There is level 4 evidence showing enhanced efficacy with the combination of vacuum-erection therapy + either PDE5 inhibitor or transurethral PGE1 or intracavernosal injection therapy. There is level 5 evidence (expert opinion) that combination therapy of PDE5 inhibitors + L-arginine or daily dosing of tadalafil + short-acting PDE5 inhibitors pro re nata may rescue PDE5 inhibitor monotherapy failures. There is level 5 evidence (expert opinion) that adding either PDE5 inhibitors or transurethral PGE1 may improve outcome of penile prosthetic surgery regarding soft (cold) glans syndrome. There is level 5 evidence (expert opinion) that the combination of PDE5 inhibitors and dapoxetine is effective and safe in patients suffering from both ED and premature ejaculation.

Arterial erectile dysfunction: different severities of endothelial apoptosis between diabetic patients "responders" and "non responders" to sildenafil

BACKGROUND

The low pharmacological response to phosphodiesterase type 5 inhibitors represents an expression of higher endothelial damage in certain categories of patients with erectile dysfunction and high cardiovascular risk. The present study evaluated this objective in type 2 diabetic patients with erectile dysfunction, classified as "non responders" to Sildenafil.

METHODS

Eighteen "responder" and twelve "non responder" type 2 diabetic patients were evaluated, relatively to different levels of endothelial damage, through the diagnostic use of a new immunophenotype of circulating endothelial progenitor cells (CD45neg/CD34pos/CD144pos) and endothelial microparticles (CD45neg/CD144pos/Annexin Vpos), recently developed and published by our group.

RESULTS

"Non responder" patients showed a significant higher severity [8.0±3.0 (International Index of Erectile Function-abbreviated version with 5 questions) vs 14.0±3.0] and duration (10.0±2.0 vs 7.0±2.0 years) of erectile dysfunction, higher level of penile arterial insufficiency (peak systolic velocity=13.0±16.0 vs 28.0±26.0cm/s; acceleration time=153±148 vs 125±128 mm/s) and finally a significant higher level of endothelial apoptosis [0.15±0.13 vs 0.05±.0.03% (serum concentrations of endothelial microparticles)] associated with higher serum concentrations of circulating late immunophenotype of endothelial progenitor cells (0.40±0.35 vs 0.12±.0.10%).

CONCLUSIONS

The results of this study corroborate the clinical value of the low clinical response to phosphodiesterase type 5 inhibitors in the treatment of erectile dysfunction in the patients with high cardiovascular risk profile, such as diabetics. In addition, the markers used in this study confirm their potential application in clinical practice as useful indicators of endothelial alteration. However, in the future we will have to assess a larger number of patients and for a longer period of observation in order to better understand the causal and temporal relations.

The relaxation effect and mechanism of action of higenamine in the rat corpus cavernosum

Higenamine mediates cardiotonic, vascular relaxation and bronchodilator effects. The relaxation effects and the mechanism of action of higenamine on the rat corpus cavernosum (CC) were assessed to investigate the effect of higenamine on penile erection. Strips of CC and aorta were used in organ baths for isometric tension studies. Tension was measured with isometric force transducers, and muscle relaxation was expressed as the percent decrease in precontraction induced by phenylephrine (PE). The relaxation reactions were investigated in an endothelial-denuded group and groups pretreated with N(G)-nitro-L-arginine methyl ester (NO synthesis inhibitor), propranolol (β-receptor blocker), indomethacin (COX inhibitor), glibenclamide (K(+)(ATP) channel inhibitor), 4-aminopyridine (membrane potential-dependent potassium channel inhibitor) and methylene blue (guanylyl cyclase inhibitor) for 30 min. Intracavernous pressure (ICP) was assessed in rats after the intravenous administration of higenamine, and changes in guanosine 3',5'-cyclic monophosphate and adenosine 3',5'-cyclic monophosphate (cAMP) concentrations were measured on the basis of the higenamine concentration. Also, the combined reaction of higenamine and the phosphodiesterase type-5 (PDE-5) inhibitors was assessed. Higenamine induced relaxation of the CC and the aortic strips precontracted with PE in a dose-dependent manner. The CC was significantly more relaxed than the aortic rings in response to the same higenamine concentration (P<0.05). The CC relaxation reaction was suppressed by the β-receptor blocker propranolol. The cAMP concentration increased gradually with increased higenamine concentration (P<0.05). The ICP also increased with increased higenamine concentration in vivo (P<0.05). In the group pretreated with 10(-7) M higenamine, the relaxation reaction of CC induced by the PDE-5 inhibitor increased significantly, compared with CC exposed to the PDE-5 inhibitor but not pretreated with higenamine (P<0.05). In conclusion, higenamine induced relaxation of the rat CC in a dose-dependent manner. The effect may be mediated through β-adrenoceptors. The results suggest that higenamine may be valuable as a new lead compound for treating erectile dysfunction.

Effects of Ginkgo biloba extracts with mirodenafil on the relaxation of corpus cavernosal smooth muscle and the potassium channel activity of corporal smooth muscle cells

In this study, we investigated the effects of a combination of Ginkgo biloba extracts (GBE) and phosphodiesterase type 5 (PDE-5) inhibitors on the muscular tone of the corpus cavernosum and potassium channel activity of corporal smooth muscle cells. Strips of corpus cavernosum from male New Zealand white rabbits were mounted in organ baths for isometric tension studies. After contraction with 1×10⁻⁵ mol l⁻¹ norepinephrine, GBE (0.01-1 mg ml⁻¹) and mirodenafil (0.01-100 nmol l⁻¹) were added together into the organ bath. In electrophysiological studies, whole-cell currents were recorded by the conventional patch-clamp technique in cultured smooth muscle cells of the human corpus cavernosum. The corpus cavernosum was relaxed in response to GBE in a dose-dependent manner (from 0.64%±8.35% at 0.01 mg ml⁻¹ to 52.28% ± 11.42% at 1 mg ml⁻¹). After pre-treatment with 0.03 mg ml⁻¹ of GBE, the relaxant effects of mirodenafil were increased at all concentrations. After tetraethylammonium (TEA) (1 mmol l⁻¹) administration, the increased effects were inhibited (P<0.01). Extracellular administration of GBE increased the whole-cell K(+) outward currents in a dose-dependent fashion. The increase of the outward current was inhibited by 1 mmol l⁻¹ TEA. These results suggest that GBE could increase the relaxant potency of mirodenafil even at a minimally effective dose. The K(+) flow through potassium channels might be one of the mechanisms involved in this synergistic relaxation.

Analysis of testosterone effects on sonic hedgehog signaling in juvenile, adolescent and adult sprague dawley rat penis

INTRODUCTION

Smooth muscle apoptosis is a major contributing factor to erectile dysfunction (ED) development in prostatectomy and diabetic patients and animal models. A critical regulator of penile smooth muscle and apoptosis is Sonic hedgehog (SHH). The SHH protein is decreased in ED models and SHH treatment of cavernous nerve (CN) injured rats prevents smooth muscle apoptosis. A close association between androgen deficiency and ED has been suggested in the literature, but few studies have examined the molecular effects on penile smooth muscle and on known signaling mechanisms that regulate morphology. Aim. Examine testosterone and SHH interaction in eugonadal adult, adolescent and juvenile rats by performing castration studies and treatment with supraphysiological testosterone.

METHODS

The eugonadal adult Sprague Dawley rats were either treated with testosterone for 7 or 14 days (N = 14) or were castrated for 4 or 7 days (N = 12). The juvenile rats were treated with testosterone for 8 days (N = 7). The adolescent rats were castrated and sacrificed at P88 (N = 8). The control rats had empty vehicle (N = 22) or sham surgery (N = 20).

MAIN OUTCOME MEASURES

The active form of SHH protein and mRNA were quantified by semi-quantitative immunohistochemical analysis and real-time reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Testosterone treatment did not alter SHH signaling in juvenile rats. Shh mRNA increased 3.2-fold and SHH protein increased 1.2-fold in rats castrated during puberty. In adult rats, castration decreased Shh mRNA 3.2-fold but did not alter SHH protein. Testosterone supplement in adult rats increased Shh mRNA 2.3-fold and decreased SHH protein 1.3-fold.

CONCLUSIONS

SHH signaling is independent of testosterone in normal juvenile rats and is sensitive to testosterone during adolescence, while testosterone supplement in the adult adversely impacts SHH signaling in a very similar manner to that observed with CN injury.

The role of hedgehog-interacting protein in maintaining cavernous nerve integrity and adult penile morphology

INTRODUCTION

Sonic hedgehog (SHH) is an essential regulator of smooth muscle apoptosis in the penis that has significant clinical potential as a therapy to suppress post-prostatectomy apoptosis, an underlying cause of erectile dysfunction (ED). Thus an understanding of how SHH signaling is regulated in the adult penis is essential to move the field of ED research forward and to develop new treatment strategies. We propose that hedgehog-interacting protein (HIP), which has been shown to bind SHH protein and to play a role in SHH regulation during embryogenesis of other organs, is a critical regulator of SHH signaling, penile morphology, and apoptosis induction.

AIMS

We have examined HIP signaling in the penis and cavernous nerve (CN) during postnatal differentiation of the penis, in CN-injured, and a diabetic model of ED.

METHODS

HIP localization/abundance and RNA abundance were examined by immunohistochemical (IHC) analysis and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) in Sprague-Dawley rats between the ages of 7 and 92 days old, in CN-injured Sprague-Dawley rats and in BioBreeding/Worcester diabetic rats. HIP signaling was perturbed in the pelvic ganglia and in the penis and TUNEL assay was performed in the penis. CN tie, lidocaine, and anti-kinesin experiments were performed to examine HIP signaling in the CN and penis.

RESULTS

In this study we are the first to demonstrate that HIP undergoes anterograde transport to the penis via the CN, that HIP perturbation in the pelvic ganglia or the penis induces apoptosis, and that HIP plays a role in maintaining CN integrity, penile morphology, and SHH abundance.

CONCLUSIONS

These studies are significant because they show HIP involvement in cross-talk (signaling) between the pelvic ganglia and penis, which is integral for maintenance of penile morphology and they suggest a mechanism of how nerves may regulate target organ morphology and function.

Toward a new 'EPOCH': optimising treatment outcomes with phosphodiesterase type 5 inhibitors for erectile dysfunction

Despite the marked adverse impacts of erectile dysfunction (ED) on quality of life and well-being, many patients (and/or their partners) do not seek medical attention for this problem, do not receive treatment or discontinue such treatment even when it has effectively restored erectile responses to sexual stimulation. Phosphodiesterase type 5 (PDE5) inhibitors are considered first-line therapies for men with ED. To help physicians maximise the likelihood of treatment success with these agents, we conducted an English-language PubMed search of articles involving approved PDE5 inhibitors dating from 1 January 1998 (the year in which sildenafil citrate was introduced), through 31 August 2008. In addition to sildenafil, tadalafil and vardenafil, search terms included 'adhere*', 'couple*', 'effect*', 'effic*', 'partner*', 'satisf*', 'succe*' and 'treatment outcome.' Based on our analysis, physician activities to promote favourable treatment outcomes may be captured under the mnemonic 'EPOCH': (i) Evaluating and educating patients and partners to ensure realistic expectations of therapy; (ii) Prescribing a treatment individualised to the couple's lifestyle needs and other preferences; (iii) Optimising treatment outcomes by scheduling follow-up visits with the patient to 'fine-tune' dosages and revisit key educational messages; (iv) Controlling comorbidities via lifestyle counselling, medications and/or referrals and (v) Helping patients and their partners to meet their health and psychosocial needs, potentially referring them to a specialist for other forms of therapy if they are not satisfied with PDE5 inhibitors.

Sonic hedgehog, apoptosis, and the penis

INTRODUCTION

Smooth muscle apoptosis in the penis is common in prostatectomy patients and animal models of erectile dysfunction (ED). A critical regulator of smooth muscle apoptosis in the penis is the secreted protein Sonic hedgehog (SHH). Since SHH protein treatment of the penis prevents cavernous nerve (CN) injury-induced apoptosis, SHH has the potential to treat post-prostatectomy apoptosis. However, little is known about how SHH signaling is regulated in the adult penis.

AIM

The goal of this review is to examine what is known about SHH signaling in the penis, to offer insight as to how SHH inhibition induces apoptosis in penile smooth muscle, and to define the role of the SHH pathway in maintaining CN integrity.

METHODS

Information presented in this review was derived from a literature search using the National Library of Medicine PubMed Services. Search terms included SHH, apoptosis, smooth muscle, penis, ED, pelvic ganglia, corpora cavernosa, CN, regeneration, Schwann cell, neural activity, and transport.

RESULTS

In this review, we have discussed the role of the CN in regulation of SHH abundance and apoptosis induction in the penis, and have examined the function and localization of SHH signaling in the CN.

CONCLUSION

There is substantial potential to develop SHH for delivery to the penis of prostatectomy patients at the time of surgery in order to prevent apoptosis induction and long-term ED development. Studies are in progress that will identify if SHH may be used as a regenerative therapy to speed CN regeneration.

Antioxidant Treatment Associated with Sildenafil Reduces Monocyte Activation and Markers of Endothelial Damage in Patients with Diabetic Erectile Dysfunction: A Double-Blind, Placebo-Controlled Study

OBJECTIVE

To investigate the synergic effect of propionyl L-carnitine (PLC) plus sildenafil in reducing monocyte oxidative activity and endothelial dysfunction markers in diabetic patients with erectile dysfunction (ED).

METHODS

Thirty-two type 2 diabetic patients with ED (according to the International Index of Erectile Function-5 [IIEF-5]) were randomized to receive PLC (2 g/d) alone (n=8) or combined with sildenafil (50 mg/d twice weekly) (n=8), sildenafil alone (50 mg/d twice weekly) (n=8), or placebo (n=8) in a double-blind, fixed-dose study. Monocyte oxidative activity (stimulation index [SI]), intercellular adhesion molecule-1 [ICAM-1], P-selectin, advanced glycation end product (AGE) levels, Doppler sonography (recording peak systolic velocity [PSV]; end diastolic velocity [EDV]; systolic wave time [SWT]; resistive index [RI]), and IIEF score were evaluated before and after 12 wk of treatment; IIEF-5 was evaluated again 4 wk posttreatment.

RESULTS

SI was reduced by treatment with PLC alone or combined with sildenafil (p<0.05). In patients treated with PLC plus sildenafil, a decrease in ICAM-1, P-selectin, and EDV values was observed compared with patients treated with sildenafil alone (p<0.05, p<0.01, p<0.001, respectively). IIEF-5 improved in all patients treated with PLC plus sildenafil or sildenafil alone (p<0.03, p<0.05, respectively). Four weeks posttreatment, patients treated with PLC plus sildenafil maintained the improvement of the IIEF-5 compared with patients on sildenafil alone (p=0.05). In patients on PLC treatment (with or without sildenafil), SI was correlated with IIEF-5 (p<0.001), glycemia with STW (p<0.03), and AGEs with IIEF-5 (p<0.01).

CONCLUSION

PLC plus sildenafil was more effective in reducing SI and endothelial dysfunction markers in patients with type 2 diabetes and ED.

Different hemodynamic responses by color Doppler ultrasonography studies between sildenafil non-responders and responders

AIM

To determine if there are different penile hemodynamic patterns between sildenafil non-responders and responders by using color Doppler ultrasonography.

METHODS

A total of 69 erectile dysfunction (ED) patients aged 22-79 years were enrolled into the present study. Thirty-eight (55.1%) men with ED who did not respond to four attempts of treatment with 100 mg sildenafil after re-education were classified as sildenafil non-responders. A combination of three vasodilator drugs, 1.25 mg papaverine, 0.4 mg phentolamine and 5 mg prostaglandin E1, was given by intracavernous injection before penile Doppler ultrasonography was carried out. The erectile response to intracavernous injection and vascular parameters including peak systolic velocity (PSV), resistance index (RI), end diastolic velocity (EDV) and cavernosa artery diameter (CD) were measured and the results between sildenafil non-responders and responders were compared.

RESULTS

No statistical difference in vascular parameters measured by Doppler ultrasonography studies between non-responders and responders was noted. Sildenafil non-responders had a poorer penile rigidity response to intracavernous injection than responders (P < 0.05). Among patients with adequate PSV (>or=30 cm/s) and abnormal EDV (> 5 cm/s), individuals in the non-responder group had fewer positive responses to intracavernous vasodilator injection than in the responder group (35.3% vs. 72.2%, P < 0.05). Advanced age and comorbidity with diabetes mellitus were significantly associated with sildenafil non-response (P < 0.05).

CONCLUSION

Sildenafil non-responders were characterized by a poorer penile rigidity response to intracavernous injection and had an associated impaired veno-occlusive mechanism. Advanced age and comorbidity with diabetes mellitus were two common factors associated with non-response.

Relationship between vascular damage degrees and endothelial progenitor cells in patients with erectile dysfunction: effect of vardenafil administration and PDE5 expression in the bone marrow

OBJECTIVES

To evaluate the levels of circulating progenitor cells (PCs) and the effect of a single dose of vardenafil 20mg on the number of these cells in men with erectile dysfunction (ED) and various degree of vascular injury at the carotid artery level.

METHODS

Sixty-eight patients with ED and various degree of carotid damage, and 25 controls were enrolled. Patients were divided into three groups according to their intima media thickness (IMT) status (normal, mild increase, or plaque). All subjects received vardenafil 20mg, and evaluation of the number of circulating PCs was performed at baseline and 4h after vardenafil administration. An RNA expression analysis of phosphodiesterase type 5 (PDE5) on bone marrow was also performed.

RESULTS

We found a significant reduction of circulating PCs in ED patients with respect to controls and a reduction in PC counts in patients with mild IMT increase or plaque, but not in those with normal IMT. Four hours after vardenafil administration we observed an increase in the number of PCs in all patients and controls. Reverse transcriptase-polymerase chain reaction analysis showed that human bone marrow expresses PDE5 messenger RNA.

CONCLUSIONS

Patients with ED and a low number of circulating PCs may be considered at increased risk for an endothelial dysfunction. An impaired response to vardenafil stimulus may be proposed as a surrogate marker of a patient's endothelial regenerative ability.

Vardenafil rescue rates of sildenafil nonresponders: Objective assessment of 327 patients with erectile dysfunction

OBJECTIVES

To prospectively investigate whether vardenafil can effectively treat patients for whom sildenafil (100 mg) has failed. The introduction of two new oral phosphodiesterase type 5 inhibitors (tadalafil and vardenafil) raises the question of whether the new agents will permit us to treat sildenafil nonresponders with another oral agent.

METHODS

Patients were seen at one institution during a 5-year period. A total of 327 patients complaining of sildenafil-refractory erectile dysfunction underwent intracavernous pharmacologic injection and color duplex Doppler ultrasonography. Subsequently 59 of these men tried vardenafil home dosing.

RESULTS

Of the 327 men in whom sildenafil failed, 16% were younger than 50, 21% were 51 to 60, 34% were 61 to 70, and 28% were older than 70 years. The Doppler diagnoses were arterial insufficiency in 154 (47%), mixed vascular insufficiency in 73 (22%), and cavernous venous occlusive disease in 57 (17%). Forty-three men (13%) had normal erectile responses to prostaglandin E1 (10 to 20 microg). Of the 59 men who tried vardenafil, 19% were younger than 50, 17% were 51 to 60, 40% were 61 to 70, and 23% were older than 70 years. The Doppler diagnoses were arterial insufficiency in 28 (42%), mixed vascular insufficiency in 10 (19%), and cavernous venous occlusive disease in 15 (29%). Six men (8%) had normal erectile responses to prostaglandin E1. Only 7 (12%) of the 59 men reported that home vardenafil dosing resulted in successful intercourse.

CONCLUSIONS

An appropriate diagnostic evaluation and subsequent treatment algorithm have yet to be established for those for whom phosphodiesterase type 5 inhibitors fail. We found that most sildenafil nonresponders had severe arterial insufficiency and were older, with 62% older than 60 years. Our preliminary experience suggests that only a small percentage (12%) of sildenafil nonresponders can be salvaged with vardenafil.

Efficacy of Tadalafil in Men with Erectile Dysfunction Naïve to Phosphodiesterase 5 Inhibitor Therapy Compared with Prior Responders to Sildenafil Citrate

INTRODUCTION

Tadalafil, an inhibitor of phosphodiesterase 5 (PDE5), is indicated for treatment of erectile dysfunction. Most tadalafil clinical trials excluded patients with unsuccessful prior treatment with sildenafil citrate (sildenafil).

AIM

This retrospective analysis of pooled data from 14 tadalafil clinical trials examines the effect of this exclusion by comparing efficacy results in 1,349 patients without prior sildenafil use (naïve, presumably a mixture of potential responders and nonresponders) with efficacy results in 1,440 patients previously responsive to sildenafil (prior responders).

MAIN OUTCOME MEASURES

Efficacy measures included the International Index of Erectile Function (IIEF) erectile function (EF) domain, overall satisfaction (OS), and intercourse satisfaction (IS) domain scores; Sexual Encounter Profile (SEP) diary questions 2 through 5 (SEP2 [successful penetration], SEP3 [successful intercourse], SEP4 (satisfaction with hardness of erection), and SEP5 [overall satisfaction with the sexual experience]); and a Global Assessment Question (GAQ1) (13/14 trials) about erection improvement. Efficacy was compared using analysis of covariance (IIEF and SEP) and logistic regression (GAQ1) models.

METHODS

After a 4-week, treatment-free, run-in period, patients in 14 double-blind, placebo-controlled, parallel-group trials were treated with tadalafil 10 mg, tadalafil 20 mg, or placebo for 12 weeks (dosed as needed before sexual activity, no more than once daily).

RESULTS

Tadalafil improved erectile function compared with placebo (P < 0.001) in naïve patients and sildenafil prior responders for all efficacy measures. For most efficacy outcomes, responses in the naïve group (probable mix of responders and nonresponders) were not statistically different from responses in the prior-responder group (P >or= 0.10).

CONCLUSIONS

The similar responses of these two patient groups observed in this post hoc analysis suggest, but do not confirm, that exclusion of sildenafil nonresponders in previously reported tadalafil clinical trials may not have substantially affected efficacy outcomes. Tadalafil improved erectile function in patients naïve to PDE5 inhibitor therapy and in patients who previously responded to sildenafil therapy.

Positive Effect of Counseling and Dose Adjustment in Patients with Erectile Dysfunction who Failed Treatment with Sildenafil

OBJECTIVE

Many patients with erectile dysfunction (ED) stop using sildenafil due to subjective failure. This study examined whether counseling and maximal dosing (100 mg) could achieve better treatment compliance and could possibly improve treatment outcome.

MATERIAL AND METHODS

Patients were recruited by newspaper advertisements and referred to 5 ED centers throughout the country. Details about their previous experiences with sildenafil were recorded and following an explicit explanation about the nature and action of the drug, were offered to enter the study. Instructions on drug use were provided during each visit in which four 100 mg Sildenafil tablets were provided. Treatment outcomes were assessed by the international index of erectile function (IIEF) questionnaire after taking 4 and 8 tablets. In 2 ED centers a short video with sexual counseling content was added in between visits.

RESULTS

The study cohort was comprised of 220 patients aged 27-88 years. The majority reported having received limited or no instructions on drug use when sildenafil was first prescribed. A significant increase in IIEF erectile function domain scores (EFDS) between visits 1, 2 and 3 was observed (10.96+/-0.40, 16.73+/-0.51 and 17.82+/-0.55 mean+/-SE, respectively), with 23.6% of the study patients achieving normal erectile function at the end of the study. The parameters of age and initial severity of ED most influenced treatment success.

CONCLUSIONS

Counseling and dose adjustment were directly influential in achieving an excellent response to a second trial of sildenafil in patients with ED who had previously failed treatment with the drug, and obviated their needing to seek more invasive measures.

Results of double-blind placebo-controlled crossover study of sildenafil citrate (Viagra) in women suffering from obstructed voiding or retention associated with the primary disorder of sphincter relaxation (Fowler's Syndrome)

OBJECTIVES

Women with the primary disorder of sphincter relaxation find voiding difficult. Studies have identified neuronal nitric oxide synthase in the female urethral sphincter, and nitric oxide donors have been shown to decrease sphincter pressures. The aim of our study was to determine if sildenafil could improve sphincter relaxation and thereby increase flow rates and improve bladder emptying.

METHODS

Twenty women with complete (5), partial retention or obstructed voiding (15) with a maximum flow rate (Qmax) of less than 15 ml/min with an elevated maximal urethral closure pressure (92--age cm H(2)O) and sphincter volume (>1.6 cm(3)) were included in the study. The study was a double-blind, randomised, placebo-control, crossover design, with patients taking sildenafil or placebo, and with measurement of flow rate and residual volume at baseline and after each treatment phase. Voiding diary, quality of life, and International Prostate Symptom Score (IPSS) data were also collected.

RESULTS

No statistical significant difference was seen in any voiding parameters and diaries when sildenafil citrate was compared with placebo. There was a significant mean decrease in IPSS of 3.64 between baseline and the sildenafil phase (p=0.0083), but not when compared with placebo. In the subgroup of women with partial retention and obstructed voiding (15/20), there was a statistically significant increase in Qmax of 4.7 ml/sec (p=0.025) between sildenafil and baseline; however this difference was not seen when compared with placebo.

CONCLUSIONS

This is the first study looking at sildenafil in voiding dysfunction in women. Clinical improvements with sildenafil were not significant when compared with placebo. Sildenafil was not effective as a therapeutic pharmacologic agent in this group of patients.

Testosterone and erectile function in hypogonadal men unresponsive to tadalafil: results from an open-label uncontrolled study

The study was aimed at investigating the efficacy of tadalafil (Cialis) in combination with transdermal testosterone (Testogel) for the treatment of tadalafil-refractory erectile dysfunction in hypogonadal patients. In an open-label, retrospective trial, 69 hypogonadal nonresponders to tadalafil monotherapy (mean age: 59 years, total testosterone < or =3.4 ng ml(-1)) were randomly divided into two homogeneous groups. Group I (n = 35) received Testogel (5 g containing 50 mg testosterone, daily) for 4 weeks, followed by concurrent therapy with tadalafil (20 mg, twice a week). Group II (n = 34) was assigned to treatment with Testogel (5 g containing 50 mg testosterone, daily) for a duration of 10 weeks before adjunctive therapy with tadalafil was initiated. Total testosterone levels were measured at baseline, week 4 and week 10. Sexual function was assessed employing the International Index of Erectile Function (IIEF). As an additional measure of efficacy, a questionnaire completed by the patients' partner was used. Mean testosterone levels were observed to increase from baseline to study end. Following 4 weeks of therapy, an improvement in Erectile Function (EF) from baseline was observed, which was greater in group I than in group II. The assessment after week 10 showed that EF had further increased and was quite similar now in both groups. Partners found that erectile capacity had greatly improved from baseline to study end. No adverse effects have been observed. These data suggest that combination therapy with testosterone and tadalafil is an effective means in a subset of hypogonadal patients who did not respond to tadalafil alone. We assume that testosterone-induced remodelling of penile tissue structure is one underlying reason for the observed improvement of erectile function. The results imply that this process may require a longer period of testosterone administration than 4 weeks.