Current status of local penile therapy

Prostaglandins as a Topical Therapy for Erectile Dysfunction: A Comprehensive Review

INTRODUCTION

Erectile dysfunction (ED) is a substantial cause of dissatisfaction among many men. This discontentment has led to the emergence of various drug treatment options for this problem.

OBJECTIVES

Unfortunately, due to various interactions, contraindications, and side effects, systemic therapies such as phosphodiesterase-5 inhibitors (including sildenafil, tadalafil, vardenafil, avanafil, etc.) are not welcomed in many patients. These problems have led researchers to look for other ways to reduce these complications.

METHODS

This article holistically reviews the efficacy of topical prostaglandins and their role in treating ED. We sought to provide a comprehensive overview of recent findings on the current topic by using the extensive literature search to identify the latest scientific reports on the topic.

RESULTS

In this regard, topical and transdermal treatments can be suitable alternatives. In diverse studies, prostaglandins, remarkably PGE1 (also known as alprostadil), have been suggested to be an acceptable candidate for topical treatment.

CONCLUSION

Numerous formulations of PGE1 have been used to treat patients so far. Still, in general, with the evolution of classical formulation methods toward modern techniques (such as using nanocarriers and skin permeability enhancers), the probability of treatment success also increases.

Current approaches to the diagnosis of vascular erectile dysfunction

Vascular erectile dysfunction (ED) is closely related to cardiovascular events, and early diagnosis of vascular ED may be helpful to predict the occurrence of cardiovascular events and improve prognosis. At present, there are many approaches to diagnose ED, but each method has its advantages and limitations. This study retrospectively reviewed all available literature focusing on the diagnosis of vascular ED through a systematic PubMed and EMBASE search. According to the different application scenarios, the main methods for the diagnosis of vascular ED are divided into four categories. Intra-cavernous injection of vasoactive drugs is the earliest method used in the diagnosis of vascular ED and is a basic test. For the diagnosis of arterial ED, color duplex Doppler ultrasound, selective penile angiography, magnetic resonance imaging, and computed tomography are more commonly used. While for the diagnosis of venous ED, shear wave elastography, dynamic infusion cavernosometry and cavernosography are more accurate. Endo-peripheral arterial tonometry (PAT) has also been used to detect vascular endothelial function. Although various existing examinations are widely used for the evaluation of vascular ED, they still have some shortcomings, such as invasiveness, contingency, high false positive (negative) rate. New methods of long-term dynamic detection are needed.

Preparation and clinical evaluation of nano-transferosomes for treatment of erectile dysfunction

Objective

The goal of the present study was to formulate topical nanocarriers of the low-cost vasodilator, papaverine hydrochloride (PH), as an alternative to the painful penile injections. The injections are used for both diagnosis and treatment of erectile dysfunction. Transdermal nano-transferosome (T), the ultraflexible nanoliposome, was used as a nanocarrier to enhance the penetration of the papaverine to the penis.

Methods

Different nano formulas were prepared and characterized for their encapsulation efficiency, particle size, zeta potential, and cumulative drug release. The formula acquired the best characteristics was incorporated into 2% (w/v) hydroxypropyl methylcellulose hydrogel base. The gel containing transferosomal papaverine hydrochloride (PH) and that containing free PH were clinically compared using color flow Doppler measurements.

Results

The results revealed that transferosome 3 (T3) had the highest entrapment efficiency approaching 72%, low particle size of 220 nm, and zeta potential of −33.4 mV. The formula released 73% of its initial drug content within 2 hours. The clinical evaluation showed the increase in the cavernous artery diameter from 0.53 mm to 0.78 mm and the increase in the peak systolic flow velocity from 5.95 cm/second to 12.2 cm/second, both of which were found to be significant at P<0.05.

Conclusion

It is evident from the study that the transferosomes can be used as a carrier of papaverine hydrochloride for both diagnosis and treatment of the erectile dysfunction. This new strategy could be used successfully in the treatment of erectile dysfunction and in male impotency.

Sildenafil can induce the onset of a cluster headache bout

About 25% of patients who are prescribed sildenafil, the phosphodiesterase type 5 (PDE-5) inhibitor, for erectile dysfunction (ED) experience headaches. These migraine effects are well-described, including cluster headaches. We report the case of a man who experienced a cluster headache attack following each of 2 sildenafil doses. His symptoms were resolved by adding naproxen to his treatment regimen and changing his ED treatment from 50 mg of sildenafil to 5 mg of vardenafil. To our knowledge, no study has reported cluster headaches triggered by the less commonly used PDE-5 inhibitors, namely vardenafil and tadalafil. Urologists should be cautious in prescribing sildenafil to patients with ED and with a history of cluster headaches. In these patients, they should consider prescribing low-dose vardenafil or tadalafil instead. Failure to recognize sildenafil risks could result in unnecessary headache bouts in patients with a history of cluster headaches.

A study of the possible effects of repeated intracorporeal self-injection of vasoactive drugs in patients with elevated end diastolic velocity during pharmacopenile duplex ultrasonography

Introduction

The aim of the work is to evaluate the effect of repeated intracavernosal self-injection of vasoactive drugs in patients with elevated End Diastolic Velocity (>5 cm/sec) during pharmacopenile duplex ultrasonography (PPDU).

Methods

Duplex evaluation was performed to the patients on self-injection therapy for comparison of end diastolic velocity and resistive index before and after completing the eight doses of IC self-injection.

Results

After the 8 trials of home therapy, 21 (52.5%) patients showed improvement in the duplex parameters regarding the end diastolic velocity, ten of them showed improvement in the EDV to the level of <5 cm/sec. The effect of different factors that may contribute to the improvement in EDV to <5 cm/sec are shown in the table 2. Age was the only predictive factor for successful response to home therapy intracavernous injection (ICI). Improvement in erectile response was assessed before and after the course of the therapy. Erection response to ICI during penile duplex improved in only six patients (E4 & E4-5)) to the point that it was sufficient for satisfactory sexual performance, 3 of them (7.5%) regained spontaneous erection and stopped using ICI (table 3). The IIEF score was 10.6 ±2.8 before the home therapy and it became 14 ±3.9 one month after completing the treatment course (P value <0.001).

Conclusions

Early rehabilitation of the patients with venous leakage ED using ICI may help to regain normal erection and avoid unnecessary penile prosthesis surgeries.

PDE5 inhibitors: considerations for preference and long-term adherence

INTRODUCTION

Erectile dysfunction (ED) is a highly prevalent condition affecting nearly one in five men worldwide. The advent of phosphodiesterase type 5 inhibitors (PDE5i) has revolutionised the ED treatment landscape and provided effective, minimally invasive therapies to restore male sexual function.

MATERIALS AND METHODS

A pubmed search was performed of all English language articles from 1996 to present reviewing PDE5i, including pharmacokinetics, efficacy profiles and comparisons, where available.

RESULTS

Currently available PDE5i in the United States include sildenafil, vardenafil, tadalafil and avanafil, each of which has unique side effect, pharmacokinetic and outcome profiles. Sildenafil is associated with increased rate of visual changes, vardenafil with QT prolongation and tadalafil with lower back pain. Avanafil and vardenafil orodispersible tablet rapidly achieve peak plasma concentration, which results in faster onset of action, whereas tadalafil exhibits the longest half-life. First time response to PDE5i is approximately 60-70%, with no significant differences in efficacy noted among therapies. The literature does not clearly demonstrate a preference for one drug. High-treatment success rates (89%) were reported when patients were prescribed all available PDE5i. Daily dosing with tadalafil is associated with improved erectile function (EF) over time. Finally, novel modes of patient-provider interaction, including internet-based education, communication and prescribing, may also improve long-term adherence.

CONCLUSIONS

PDE5i represent first line therapy for ED with excellent overall efficacy and satisfactory side effect profiles. Enhanced communciation, coupled with increased knowledge of drug characteristics, comparative treatment regimens and optimal prescribing patterns, offer compelling tools to improve long-term treatment success.

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.

Combined intracavernous vasoactive drugs and sildenafil citrate in treatment of severe erectile dysfunction not responding to on-demand monotherapy

Objective

To investigate the effect of chronic use of sildenafil and intracavernous injection (ICI) with trimix in men not responding to on-demand monotherapy with sildenafil or ICI with prostaglandin-E1 (PGE1).

Patients and methods

The study included 40 patients with erectile dysfunction (ED), with a mean (SD) age of 50.7 (11.3) years and unresponsive to on-demand sildenafil or ICI with PGE1 as monotherapy. They were assessed using the Sexual Health in Men (SHIM)-5 score for ED severity, penile colour Doppler ultrasonography (CDUS) for peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistance index (RI) with an ICI test using 0.25 mL of trimix of papaverine, PGE1 and phentolamine. Testosterone, prolactin and cholesterol levels were assessed. Patients received 25 mg sildenafil daily for 8 weeks, combined with twice weekly ICI with 0.25 mL of trimix. After treatment, the Erection Hardness Score (EHS), penile CDUS with ICI and ED Inventory of Treatment Satisfaction were assessed.

Results

The mean (SD) SHIM-5 score before treatment was 8.3 (0.5) in 15 of the 40 men and 6.3 (0.4) in 25. Penile haemodynamics were normal in five (13%), showed arterial insufficiency in five (13%), venous occlusive disease in 26 (65%) and mixed vascular in four (10%). There was an improved SHIM-5 score in 28 (70%) patients, as shown by their haemodynamic values, duration of erection and EHS with therapy, and 66% satisfaction with treatment. Adverse effects (penile pain, headache, facial flushing, dyspepsia, nasal congestion, dizziness) were reported in 17 patients (43%).

Conclusion

Chronic use of trimix plus daily low-dose sildenafil improved penile haemodynamics in these patients with ED not responding to on-demand phosphodiesterase-5 inhibitors or ICI with PGE1 monotherapy.

Nanoparticles as a novel delivery vehicle for therapeutics targeting erectile dysfunction

INTRODUCTION

Nanoparticles represent a potential novel mechanism for transdermal delivery of erectogenic agents directly to the penis.

AIM

To determine if nanoparticles encapsulating known erectogenic agents (tadalafil, sialorphin, and nitric oxide [NO]) can improve erectile function in a rat model of erectile dysfunction (ED) as a result of aging (the Sprague-Dawley retired breeder rat).

METHODS

Nanoparticles encapsulating the erectogenic agents were applied as a gel to the glans and penile shaft of anesthetized Sprague-Dawley rats and the intracorporal pressure/blood pressure (ICP/BP) monitored for up to 2 hours with or without stimulation of the cavernous nerve. Control nanoparticles were made without encapsulating erectogenic agents and applied in a similar manner in separate experiments.

RESULTS

Nanoparticles encapsulating NO caused spontaneous visible erections in the rat, with an average time of onset of 4.5 minutes, duration of 1.42 minutes, and ICP/BP of 0.67 +/- 0.14. The sialorphin nanoparticles also caused visible spontaneous erections after an average of 4.5 minutes, with a duration of 8 minutes and ICP/BP ratio of 0.72 +/- 0.13. The difference in the erectile response between groups of animals treated with NO or sialorphin nanoparticles was significantly different from the control group treated with empty nanoparticles (P < 0.05) Tadalafil nanoparticles showed a significant increase in the mean ICP/BP (0.737 +/- 0.029) following stimulation of the cavernous nerve (4 mA) 1 hour after application of the nanoparticles with a visibly improved erectile response.

CONCLUSIONS

Nanoparticles encapsulating three different erectogenic agents resulted in increased erectile function when applied to the penis of a rat model of ED. Nanoparticles represent a potential novel route for topical delivery of erectogenic agents which could improve the safety profile for existing orally administered drugs by avoiding effects of absorption and first-pass metabolism, and would be less hazardous than injection.

Repeated intracorporeal self-injection: effect on peak systolic velocity and cavernosal artery diameter

This work is aimed at evaluating the effect of repeated intracavernosal injection (ICI) self-injection on the peak systolic velocity (PSV) and the diameter of cavernosal arteries. Sixty erectile dysfunction (ED) patients who were positive responders for ICI therapy were studied. Pharmacopenile duplex ultrasonography (PPDU) was carried out before starting ICI and after 10 doses of home therapy in an open-label uncontrolled study. There was significant increase in the cavernosal artery diameter and their PSV before and after injection. Cavernosal arteries diameter before injection in both right and left sides was 0.64+/-0.13 and 0.63+/-0.12 mm at the start and became 0.81+/-0.22 and 0.79+/-0.22 mm respectively at the end with significant differences (P<0.001). Cavernosal arteries diameter after injection in both right and left sides was 1.10+/-0.18 and 1.09+/-0.19 mm at the start and became 1.34+/-0.39 and 1.27+/-0.33 mm respectively at the end with significant differences (P<0.001). PSV at the start was 33.77+/-13.26 and 32.33+/-8.09 cm/s on both right and left sides and became 44.4+/-1.19 and 46.1+/-5.86 cm/s respectively at the end with significant differences (P<0.001). It is concluded that repeated ICI improves arterial erectile response with associated increase in PSV and cavernosal artery diameters.

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.

In vitro viability of human cavernosal endothelial and fibroblastic cells after exposure to papaverine/phentolamine and prostaglandin E1

OBJECTIVE

To investigate the influence of commercially available vasoactive drugs on human cavernosal endothelial and fibroblastic cells in vitro, as although corporal fibrosis is a well known side-effect of intracavernosal injection therapy for erectile dysfunction, the possible detrimental effect of these agents on the endothelium lining the cavernosal vascular spaces is uncertain.

MATERIALS AND METHODS

Cultured primary endothelial (13) and fibroblastic cells (12), obtained from potent patients undergoing penile surgery, were exposed to different physiological dilutions of prostaglandin E1 (PGE1), papaverine/phentolamine or the respective triple-mix of these agents for 30 min. Viable cells were counted and cell metabolic activity measured in these cultures 48 h after drug exposure.

RESULTS

There was a significant dose-dependent decrease in the viable cell count after exposure to papaverine-containing formulations, probably because of the low pH of this substance. This cytotoxic effect was more pronounced in endothelial than in fibroblastic cells, and was not apparent in the PGE1 groups. The relative increase in cell metabolic activity in cultures affected by a moderate cytotoxic effect indicated a regenerative process.

CONCLUSION

These comparative results in endothelial and fibroblastic cell cultures suggest that the endothelium rather than the interstitium of the corpus cavernosum is more sensitive to side-effects produced by intracavernosal injection therapy with papaverine. Thus, unfavourable consequences on the function of the endothelial layer might be as important as the risk of interstitial fibrosis. As these effects were not detected for PGE1 this drug should be preferred to papaverine in clinical practice.

A prospective randomized study to optimize the dosage of trimix ingredients and compare its efficacy and safety with prostaglandin E1

Intracavernous injection of Trimix (Tx) is indicated for patients unsuitable for prostaglandin E1 (PgE1) injection due to lack of response, pain or cost. We believe that the ideal ratio of ingredient doses in Tx is yet to be found. We postulated that increasing the doses of individual drug components in an orderly manner would convey important data on penile hemodynamic response. Such information is needed to choose an effective and less costly alternative to PgE1 with least side effects. We set out to evaluate the impact of varying the ingredient dosage on response and short-term safety of Tx compared with PgE1. We prospectively randomized 180 consecutive patients with erectile dysfunction into nine equal groups and each group received a different dose of Tx, namely phentolamine (1 mg) plus one dose of PgE1 (2.5, 5 or 10 microg) and one dose of papaverine (5, 10 or 20 mg). Each patient was injected with 20 microg PgE1 and one dose of Tx in two clinic visits 1 week apart. Following injection, duplex ultrasound of cavernous arteries and axial rigidometry were carried out. Patients ranked the quality of erection, estimated overall satisfaction and reported time to detumescence and side effects. Patients' mean age was 50.5+/-11.7 y with underlying organic condition in 91.1%. There were no significant differences between PgE1 and Tx with regard to peak cavernous artery flow, time to erection, patients' satisfaction, average axial rigidity and pain. PgE1 produced higher end diastolic velocity, shorter duration of erection and less priapism. Patients did not show a preference for either drug or any particular dosage. We conclude that even at the smallest dose of ingredients of Tx, there are no significant differences in hemodynamic effects, rigidity, pain and self-satisfaction between the two drugs. However, Tx produces a longer duration of erection and more priapism than PgE1.

Intracavernous Sodium Nitroprusside (SNP) versus Papaverine/Phentolamine in Erectile Dysfunction: A Comparative Study of Short‐Term Efficacy and Side‐Effects

OBJECTIVE

The aim of our work is to evaluate the efficacy of intracavernous sodium nitroprusside (SNP) in management of erectile dysfunction (ED) in a clinical comparative study with papaverine/phentolamine in ED patients.

METHODS

The study included 40 patients with ED divided into two groups. Group I include 20 patients receiving intracavernous (30 mg papaverine + 1 mg phentolamine) followed 1 week later by intracavernous 300 microg SNP. Group II included 20 patients receiving the same regimen of group I but with intracavernous SNP first followed by papaverine/phentolamine 1 week later. All patients were assessed clinically for their response and any developing complications.

RESULTS

The numbers of good and poor responders were not statistically significant (P > 0.05) among the two groups. The mean erectile duration of SNP was similar to bimix (P > 0.05). No side-effects whether local or systemic occurred with SNP while priapism and local penile pain were recorded with bimix solution.

CONCLUSIONS

Intracavernous pharmacotherapy is still a reliable method both for diagnosis and for treatment of ED. While preliminary results of our study show a potential of SNP to be an effective and safe intracavernous agent, long-term self-injection clinical trials are needed before large-scale usage is recommended.

Current concepts in the management of erectile dysfunction in men with prostate cancer

Development in the management of prostate cancer has placed increased attention on patient quality of life after treatment, particularly sexual function. The incidence of erectile dysfunction (ED) in men following radical prostatectomy has been estimated to range from 16% to 82%. Several factors determine the postoperative incidence of erectile difficulties; these include patient age, degree of cavernosal nerve sparing during surgery, cancer stage, and associated comorbidities. Early initiation of available treatments after radical prostatectomy, such as phosphodiesterase-5 (PDE-5) inhibitors and intracavernosal alprostadil, may improve the speed and degree of recovery of erectile function. Oral PDE-5 inhibitors are recognized as the first line of therapy for men with ED after radical prostatectomy, with reasonable success rates reported for all commercially available PDE-5 inhibitors. In recognition of the neurogenic basis for erectile dysfunction after radical prostatectomy, new strategies have been devised, such as cavernous nerve graft interposition procedures, perioperative neuroprotection measures, and postoperative neurotrophic treatments. Hopefully, these efforts will improve quality of life for patients with prostate cancer. The aim of this article is to review the current modalities of ED management for men with prostate cancer.

Intracavernous Chlorpromazine Versus Phentolamine: A Double‐blind Clinical Comparative Study

INTRODUCTION

Intracavernous pharmacotherapy is one of the most common treatment modalities of erectile dysfunction (ED). There are different drugs that are used for intracavernous injection including papaverine, phentolamine, prostaglandins E1, phenoxybenzamine, and moxisylate.

AIM

The aim of this study is to evaluate the efficacy of chlorpromazine as an intracavernous vasoactive agent alone or with other drugs.

METHODS

This study was performed on 50 patients presenting to our department complaining of ED. Patients were divided into three groups according to the type of intracavernous drug injected. Group A included 20 patients who received an intracavernous injection of 1 mL bimix (30 mg papaverine + 1 mg phentolamine) followed a week later by intracavernous test dose using a 1 mL mixture of papaverine and chlorpromazine (30 mg papaverine + 2.5 mg chlorpromazine). Group B included 20 patients who received an intracavernous injection of 1 mL trimix (30 mg papaverine + 1 mg phentolamine + 10 microg PGE1). A week later they received another intracavernous test dose using a 1 mL mixture of papaverine, PGE1, and chlorpromazine (30 mg papaverine + 2.5 mg chlorpromazine + 10 microg PGE1). Group C included 10 patients who received various intracavernous injections of chlorpromazine in doses 1 mg, 2 mg, 5 mg, and 10 mg.

RESULTS

There was no significant difference in erection response and erection duration between phentolamine and chlorpromazine. Prolonged erection occurred in two patients of group B and postural hypotension occurred in three patients of group C.

CONCLUSION

Chlorpromazine can be used as an intracavernous vasoactive agent; it is similar to phentolamine in efficacy and short-term side effect profile.

Cytotoxicity of different intracavernous vasoactive drugs on cultured endothelial cells of human corpus cavernosum penis

OBJECTIVES

To investigate the cytotoxic effect of prostaglandin E(1) (PGE(1)), a standard combination of papaverine/phentolamine, and a triple mixture of these agents on human cavernosal endothelial cells using a cell culture model. The endothelial layer of the corpus cavernosum plays an important role in signal transduction of penile erection and is directly exposed to vasoactive agents after intracavernous injection for erectile dysfunction.

METHODS

Primary endothelial cells were obtained from the corpus cavernosum of 13 potent patients undergoing penile surgery. Cultured cells were exposed for 30 minutes to physiologic dilutions of 20 microg PGE(1), 30 mg papaverine/1 mg phentolamine, or the same dosages of the triple mixture of these agents, each dissolved in 5 to 50 mL sodium chloride. Lactate dehydrogenase release as a cytotoxicity marker was measured 6 hours after drug exposure, and the total cell metabolic activity was quantified after 48 hours with a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS)-based assay. Additionally, the amount of viable cells was identified with a dual fluorescent staining procedure.

RESULTS

The initial release of lactate dehydrogenase was elevated up to 3.2-fold in the concentrated papaverine/phentolamine and triple mixture group compared with PGE(1) and the control. After 48 hours, the papaverine-containing formulations led to a significant dose-dependent decrease in the viable cell count and metabolic activity of the cultures that was not noticed with PGE(1).

CONCLUSIONS

These in vitro data strongly suggest an unfavorable effect of vasoactive agents containing papaverine on cavernosal endothelial cells. Before fibrotic changes of the smooth muscle stroma, the functionally important endothelium of the corpus cavernosum might suffer significantly from intracavernous injection therapy. Therefore, papaverine should no longer be used for this indication.

Sexual dysfunction and diabetes

Erectile Dysfunction (ED) is common in men with diabetes. Diabetic men are three times as likely to develop ED as non-diabetic men. The cause is multifactorial, but most commonly reflects endothelial dysfunction and autonomic neuropathy. Diabetes and vascular disease often coexist and ED may be a marker for silent occlusive arterial disease, for which the patient should be screened. Many men still do not volunteer their problem, hence, routine questioning by health care professionals is an important part of the overall management because of the deleterious effect of ED on relationships, self-esteem and quality of life. Treatment is effective in the majority and all options should be considered, beginning with the much preferred oral phosphodiesterase type 5 inhibitors (sildenafil, tadalafil, vardenafil). Female Sexual Dysfunction or Disorder (FSD) is more difficult to define and specific studies in diabetics are limited. Problems with arousal, lubrication and orgasmic dysfunction occur, but the fatigue of diabetes may be influencing these complaints, and in general, psychological issues appear to predominate.

Clinical and sonographic assessment of the side effects of intracavernous injection of vasoactive substances

The objective of this study is to evaluate the side effects of intracavernous vasoactive agents on clinical and sonographic basis. Two groups of patients were included, group I included 168 ED patients trained on self-injection therapy using one of the three protocols. Protocol A: papaverine; protocol B: PGE1; and protocol C: trimix (papaverine, phentolamine and PGE1). Patients were followed up clinically, sonographically and by laboratory investigations for 6 months to evaluate the occurrence of side effects. Group II included 21 patients presenting to our department for the first time with a complication of intracavernous injection pharmacotherapy (ICI) initiated elsewhere. In all, 168 patients of group I completed the study. Patients on papaverine had the highest incidence of complications concerning prolonged erection, subcutaneous hematoma and penile fibrosis. Postinjection penile pain was observed more with groups B and C than group A. No systemic side effects were reported. Duplex ultrasound was beneficial in detecting mild clinically impalpable fibrosis. In total, 10 patients of group II presented with prolonged erection, seven with penile fibrosis, three with cavernositis and one with intracavernous needle breakage. We conclude that although ICI therapy is an effective second-line treatment option, patients on a self-injection program should be followed up both clinically and sonographically both at the initiation phase and on regular follow-up visits.

Viability and safety of combination drug therapies for erectile dysfunction

PURPOSE

In some patients with erectile dysfunction (ED) oral, topical or intracavernous drug therapy fails. However, several classes of drugs demonstrate efficacy for ED, creating the potential for pharmacological combinations preferable to implantation of a penile prosthesis.

MATERIALS AND METHODS

Preliminary reports suggest that combining oral, topical or intracavernous drugs may salvage patients in whom monotherapy fails.

RESULTS

Agents that lead to activation or increases in cyclic nucleotides (cyclic adenosine monophosphate and guanosine monophosphate) with or without nitric oxide donors or nitrates, or alpha-adrenergic antagonists have been used to treat ED. The phosphodiesterase-5 inhibitor sildenafil has been combined with alprostadil (prostaglandin E1) and administered by either the intraurethral or intracavernous route. Successful intercourse following this combination varies from 47% to 100% when monotherapy with each has failed. The introduction of apomorphine has led to its unapproved use in combination with sildenafil in Europe. Combination strategies may allow lower drug doses and reduced adverse effects.

CONCLUSIONS

The encouraging preliminary observations combined with the potential for adverse events provide a scientific rationale for prospective, randomized clinical trials with adequate numbers of subjects.

Pharmacological management of erectile dysfunction

Erectile dysfunction (ED) is a common medical condition that affects the sexual life of millions of men worldwide. Many drugs are now available for treating ED; oral pharmacotherapy represents the first-line option for most patients with ED. Sildenafil, an inhibitor of the enzyme phosphodiesterase type 5, is currently the most widely prescribed oral agent and has a very satisfactory efficacy-safety profile in all patient categories. Apomorphine SL is a dopamine D1- and D2-receptor agonist which has recently been approved for marketing in Europe. It is best selected for treating patients with mild to moderate ED. Vardenafil and tadalafil are new phosphodiesterase type 5 inhibitors which are expected to be approved this year. Both of them have significant positive efficacy-safety profiles. Patients who do not respond to oral pharmacotherapy or who cannot use it are good candidates for intracavernosal and intraurethral therapy. Alprostadil is the most widely used drug, both for injection therapy and for the intraurethral route. The efficacy of second-line treatment is high but the attrition rate remains significant.

Erectile function after radical prostatectomy: a review

OBJECTIVES

Although the high rate of erectile dysfunction (ED) following prostatectomy is well recognised, the aetiology and pathophysiology have not yet been fully elucidated. We examined the current literature as to aetiology, treatment and possible prevention of ED following prostatectomy.

METHOD

Review of the literature by a Medline search.

CONCLUSION

The most important predictors of erectile function are pre-operative erectile function and the nerve sparing nature of the procedure. The former is determined by age and vascular risk-factors whereas the latter is decided by the stage of the tumour and the skill of the surgeon. The value of intraoperative nerve mapping seems limited and the importance of nerve grafting is uncertain. Natural recovery of erection can take as long as 24 months. Patients complain about a lack of professional support. Symptomatic therapy may be applied according to the current general standards of treatment in men with ED.