Erectile dysfunction and treatment of carcinoma of the prostate

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

Sildenafil: A 4-year update in the treatment of 20 million erectile dysfunction patients

Sildenafil citrate, the first internationally approved and widely used oral agent for the treatment of erectile dysfunction (ED), has revolutionized the treatment of ED throughout the past 5 years. This phosphodiesterase type-5 (PDE-5) inhibitor is selective for corpus cavernosum smooth muscle tissue and produces excellent erectile function. Its efficacy and safety over a wide variety of etiologies of ED and severities of ED demonstrates its usefulness in the clinical treatment of these patients. More than 20 million men have been treated worldwide with sildenafil with excellent results. ED caused by difficult-to-treat etiologies such as radical prostatectomy, severe diabetes, and spinal cord injury have demonstrated efficacy. Although sildenafil citrate, like all PDE-5 inhibitors, is contraindicated in patients taking nitrate medications for cardiac disease, it is effective and safe for those cardiovascular patients who are not taking nitrate medications. The incidence of adverse cardiovascular events in patients taking sildenafil does not differ from those of the general population. Investigations into the pharmacologic effect of sildenafil on coronary myocardial tissue further supports the safety of this medication. Sildenafil has been safe and effective in patients taking various medications including multiple antihypertensive drugs, selective serotonin reuptake inhibitors, cardiac, and diabetic medications.     

Long-term efficacy and compliance of MUSE for erectile dysfunction following radical prostatectomy: SHIM (IIEF-5) analysis

Baseline and follow-up data of 54 patients from a single surgical series (1998-2001), who used medicated urethral system for erection (MUSE) for the erectile dysfunction (ED) associated with radical prostatectomy (RP), were obtained. Patients were surveyed using the abridged five-item version of the International Index of Erectile Function (IIEF) questionnaire, commonly referred to as the Sexual Health Inventory of Men (SHIM), to determine presence and severity of ED and efficacy of ED treatment modalities. The mean patient age was 63.7+/-5.6 y and the mean follow-up period was 2.3+/-1.2 y. All patients experienced ED for at least 6 months after their surgery before starting MUSE therapy. Overall, 55% of the patients achieved and maintained erections sufficient for sexual intercourse while on MUSE and 48% continued long-term therapy with a mean use of 2.32+/-1.2 y. The mean presurgery SHIM score in these patients was 19.2+/-1.3, which decreased to 5.2+/-0.5 after surgery and increased to 16.3+/-1.3 after MUSE treatment. A total of 28 patients (52%) discontinued treatment after a mean use of 8+/-1.4 months. The reasons for discontinuation were insufficient erections (n = 16, mean SHIM score of 10.5+/-4.4), switch to other ED therapies (n = 4), natural return of erections (n = 4) and urethral pain and burning (n = 4). Excluding the patients (n = 8) who preferred other therapies and return of natural erections, the compliance to MUSE was 63%. There were no significant differences in the IIEF-5 responses between the patients who had a nerve-sparing technique (n=34) and those who did not (n = 20) or among patients who used different doses (250, 500 or 1000 microg) of MUSE. The results of the current trial indicate that MUSE is a successful treatment option in RP patients with established ED. It appears that a post-treatment SHIM score of > or = 16 defines a successful outcome with MUSE therapy.     

Testosterone and erectile dysfunction

Aging is associated with a decline in several important health factors in men, including libido. Serum testosterone concentrations also decrease with age, and many age-related clinical features are closely associated with androgen deficiency, including erectile function (ED). Approximately 70% of ED is of organic origin, with the major risk factors being diabetes mellitus, hypercholesterolemia, smoking and chronic medical illnesses. These are also established risk factors for atherosclerosis, which is the predominant predisposing factor of vasculogenic ED. The introduction of phosphodiasterase-5 (PDE-5) inhibitors for the treatment of ED made a significant impact both in terms of clinical efficacy, and increasing the awareness of the condition. In spite of this, some patients fail to respond to PDE-5 inhibitors alone. Both animal and clinical studies indicate that testosterone therapy improves both erectile function and the response to PDE-5 inhibitors in patients with ED and hypogonadism. Indeed, interventional studies demonstrate that testosterone replacement therapy improves erectile function in hypogonadal men who have previously failed to respond to PDE-5 inhibitors alone. Furthermore, it has been demonstrated that the full therapeutic potential of PDE5 inhibitors will only become manifest in a eugonadal state. Recent studies have demonstrated a close relationship between testosterone and ED and suggest that testosterone therapy may be a valuable option for an increasing number of affected men. European guidelines recommend that all men presenting with ED should have their testosterone concentrations measured.     

Sexual functions of men with obstructive sleep apnoea syndrome and hypogonadism may improve upon testosterone administration: a pilot study

This study examined 72 patients with obstructive sleep apnoea syndrome (OSAS), confirmed by polysomnography. Thirty-two patients were suffering from erectile dysfunction (ED) assessed by IIEF-5 questionnaires and confirmed by nocturnal penile tumescence examination. Their testosterone levels were measured. Eight patients had normal testosterone levels and were treated with a PDE-5 inhibitor (vardenafil) only; after 6 months of treatment, 6 of these patients (75%) showed significant improvement in erectile function. The remaining 24 patients with OSAS, ED and hypogonadism (total testosterone <12 nmol l⁻¹), were divided into two groups based on the indication for continuous positive airway pressure (CPAP) therapy: five patients received CPAP therapy (group 1) and 19 patients did not (group 2). The patients of group 2 received only a PDE-5 inhibitor (vardenafil 20 mg) for ED; and eight patients (42%) showed an improvement after 3 months of treatment. The five patients receiving CPAP therapy were treated with a combination of parenteral testosterone undecanoate and a PDE-5 inhibitor (vardenafil) and all had normal erectile function after 3 months of therapy. The results suggest positive effects of addition of testosterone to treatment with PDE-5 inhibitors in hypogonadal men with OSAS, which should be confirmed in larger controlled studies.     

The costs of caring for erectile dysfunction in a managed care setting: evidence from a large national claims database

PURPOSE: We examined the direct costs of erectile dysfunction (ED) empirically. MATERIALS AND METHODS: A naturalistic cohort study was done in 285,436 patients with ED and 51 health plans that covered 28 million lives nationwide from 1999 through 2001. Based on claims that had an ED related diagnosis code, procedure code or medication code we categorized the cost structure of ED care and calculated the annual costs of ED care per patient with ED, per user and per member monthly for individual and for all categories of ED care. RESULTS: A patient with ED in a health plan spent about an average of 83.91 dollars in 1999, 95.41 dollars in 2000 and 119.26 dollars in 2001 for ED care. In 2001, 37.08% of ED care costs per patient with ED were spent on phosphodiesterase type 5 (PDE-5) inhibitor therapy, 14.36% were spent on physician office visits, 10.19% were spent on diagnosis procedures, 8.45% were spent on testosterone hormone therapy, 3.85% were spent on penile prosthesis implantation, 4.41% were spent on intracavernous injection, 2.68% were spent on alprostadil pellet insertion and 0.81% was spent on vacuum erection devices. Of the 7 commonly used ED treatments PDE-5 inhibitor therapy has the lowest annual cost per user. CONCLUSIONS: In 2001 ED imposed a 122,669 dollars annual burden to a health plan with 100,000 members, that is or 0.108 dollars per member monthly. Each patient with ED spent 119.26 dollars annually for all ED related services or treatments. Of the 7 commonly used treatments PDE-5 inhibitor therapy had the lowest annual cost per user.     

Hypogonadism and erectile dysfunction: the role for testosterone therapy

The role of low testosterone levels in erectile dysfunction (ED) remains unclear. Both organic and psychogenic factors contribute to ED, with vasculogenic causes being the most common etiology. Approximately 10-20% of patients with ED are diagnosed with hormonal abnormalities. At the physiologic level, two second messenger systems are involved in mediating erections, one involving cyclic adenosine monophosphate (cAMP) and the other involving cyclic guanosine monophosphate (cGMP). PDE5 inhibitors such as sildenafil promote the cGMP pathway, while alprostadil affects the cAMP pathway. Evidence is strong that, in animal systems, testosterone has direct effects on erectile tissue. However, although testosterone clearly has an impact on libido in humans, its effect on penile function is less clear. Evaluation of ED includes medical, sexual, and psychosocial history assessments, as well as laboratory tests to check for diabetes and hormonal abnormalities. Initial interventions should involve correction of potentially reversible causes of ED, such as hypogonadism. First-line therapy for other patients is typically oral PDE5 inhibitors, such as sildenafil, tadalafil, or vardenafil. For patients who fail treatment with PDE5 inhibitors, local therapies such as intracavernous alprostadil are highly successful. Recent data also support the success of combination therapy with sildenafil and testosterone. This opens the possibility of other combinations of testosterone and other treatments of ED. The ability to exploit multiple pathways in the physiologic processes leading to erection may help improve therapy for ED.     

Erektile Funktionsstörungen

Erectile dysfunction is a common, age-dependent functional disturbance of men associated to various comorbidities. Interdisciplinary cooperation with neurologists in cases of a suspected neurological aetiology and with psychiatrists in cases with normal organic diagnostic findings is necessary. Hormone replacement and psychotherapy can cure certain patients. Oral pharmacotherapy is the most effective therapy for erectile dysfunction with the highest patient preference. Oral PDE-5-inhibitors(sildenafil, tadalafil, vardenafil) are superior in effectiveness to centrally acting drugs(apomorphin, yohimbine). Local pharmacotherapy (MUSE, ICI) is a second line therapy in cases of failure or contraindications for oral pharmacotherapy. Vacuum therapy and operative procedures(penile implants) complete the therapeutic options of erectile dysfunction.     

Effects of testosterone on erectile function: implications for the therapy of erectile dysfunction

Sexual potency declines with age, as does the efficiency of erection. Many studies show that different patterns of erectile dysfunction (ED), varying from occasional inability to obtain a full erection, impairment throughout intercourse and total absence of erectile response, might not be triggered by psychological factors only. Recent research indicates that ED relies on organic causes, and has challenged the development of new therapies. One therapeutic approach in patients who have testosterone deficiency is based on androgen therapy. Thus, we reviewed data on testosterone-induced effects relative to erectile function, summarizing the results from studies reported in 1991-2006 on testosterone therapy in patients with ED and hypogonadism, with a special focus on men not responding to phosphodiesterase-5 (PDE-5) inhibitors. We searched several computerized databases parallel with printed bibliographic references. Many studies have established animal models, which confirm that testosterone is important in modulating the central and peripheral regulation of ED. Testosterone deprivation has a strong negative impact on the structure of penile tissues and erectile nerves, which can be prevented by androgen administration. Combined therapy regimens with PDE-5 inhibitors and testosterone might improve ED in patients with hypogonadism of different causes. Thus, androgen treatment in hypogonadic patients, including those unresponsive to PDE-5 inhibitors, often results in an improvement of ED. Testosterone therapy is safe and convenient, while rapidly correcting low testosterone levels.     

Synergetic effect of testosterone and phophodiesterase-5 inhibitors in hypogonadal men with erectile dysfunction: A systematic review

Testosterone deficiency seems to impair the clinical response to phophodiesterase-5 (PDE-5) inhibitors in patients with erectile dysfunction (ED). In hypogonadal men, testosterone repletion was associated with enhanced sexual function in patients who failed initial treatment with sildenafil or tadalafil. We conducted a systematic review of studies that evaluated combination therapy of testosterone and PDE-5 inhibitors in patients with ED and low, low-normal testosterone levels who failed monotherapy. The studies we examine are heterogeneous with several methodological drawbacks and that, overall, the addition of testosterone to PDE-5 inhibitors might benefit patients with ED associated with testosterone <300 ng/dL (10.4 nmol/L) who failed monotherapy. Further studies, with a randomized placebo-controlled and double blind design, are needed to describe the appropriate target patient group, testosterone cut-off and to define the optimal dose and duration of combination therapy.     

Prevention and Management of Postprostatectomy Erectile Dysfunction

ContextErectile dysfunction (ED) is the complication associated with radical prostatectomy (RP) for clinically localized prostate cancer that has the most negative impact. Currently, several therapeutic options are available to improve sexual health after surgical treatment.ObjectiveTo critically analyze the factors affecting erectile function after RP and to evaluate the evidence suggesting the role of pharmacologic prophylaxis and treatment of ED after surgery.Evidence acquisitionThis article is based on the proceeding of the Risk Evaluation and Mitigation Strategy (REMS) meeting held in Madrid, Spain, in 2007.Evidence synthesisSeveral basic science reports have highlighted a potential role of phosphodiesterase type 5 inhibitors (PDE5-Is) in the prevention of endothelial damage related to ischemia–reperfusion and/or denervation following surgery. However, patient selection and preservation of both nerves and vascular supply integrity are the major determinants of postoperative erectile function. Pharmacologic treatment of postoperative ED, using either oral or local approaches, is effective and safe. Moreover, recent studies have shown that pharmacologic prophylaxis early after RP can significantly improve the rate of erectile function recovery after surgery. Use of on-demand treatments for treatment of ED in post-RP patients has been shown to be highly effective. In this context, pharmacologic prophylaxis may potentially have a significant expanding role in future strategies aimed at preserving postoperative erectile function.ConclusionsAdministration of pro-erectile drugs is the key factor of erectile function recovery after RP. Use of on-demand PDE5-Is in post-RP patients has been shown to be effective and safe, with better results seen in select young patients treated with a bilateral nerve-sparing approach. Pharmacologic prophylaxis may have a role in the future. Large, multicentric, placebo-controlled trials are urgently needed in order to identify the best regimen for treating postsurgery ED.     

PDE-5 inhibitors: current status and future trends

Phosphodiesterase-5 (PDE-5) inhibitors are a well-established, first-line therapy for erectile dysfunction (ED). Extensive clinical trials and clinical experience established the highly significant efficacy and the safety of this class of drugs in the treatment of ED.Furthermore, the efficacy of PDE-5 inhibitors has been established in men with ED with a broad range of etiologies and comorbidities. The future of PDE-5 inhibitors includes the expansion of indications such as the treatment of pulmonary hypertension and the potential of treatment of symptomatic BPH.     

Initial results utilizing combination therapy for patients with a suboptimal response to either alprostadil or sildenafil monotherapy

OBJECTIVE: Intraurethral alprostadil and oral sildenafil are useful in selected patients. However, there continues to be a significant treatment failure rate. Since their mechanisms of action are different, we wanted to evaluate the effectiveness of combination therapy. MATERIALS AND METHODS: Of 214 patients treated for erectile dysfunction (ED), 65 were not fully satisfied with the firmness of their erections via monotherapy. Responses were evaluated using the International Index for Erectile Function (IIEF) questionnaire before and after treatment. Group I consisted of 33 patients who tried maximal dose intraurethral alprostadil monotherapy initially, followed by the maximal dose of sildenafil monotherapy, and were still unsatisfied. Group II consisted of 32 patients who tried the maximal dose sildenafil monotherapy initially, followed by the maximal dose of alprostadil monotherapy, and were also unsatisfied. There 65 patients then underwent combination therapy. RESULTS: 60 out of the 65 patients stated they were satisfied with combination therapy. Questionnaire scores for erectile function were 23.1+/-2.0 (114%) for combination therapy vs. 19.2+/-1.8 (77%) and 15.2+/-1.6 (41%) for sildenafil and alprostadil monotherapies (p<0.05). There were no significant differences in responses between the two groups. The men also reported improvement in intercourse and overall satisfaction. CONCLUSIONS: Combination therapy may be an option for motivated patients who have a suboptimal response from monotherapy.     

Alpha-adrenoceptors are a common denominator in the pathophysiology of erectile function and BPH/LUTS--implications for clinical practice

A literature search of PubMed documented publications and abstracts from proceedings of scientific meetings was made to review the available data on benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) and erectile dysfunction (ED) with a special focus on the role of alpha-adrenoceptors as critical mediators of pathophysiology. The reader is introduced to clinical results on the therapeutic potential of alpha-blockers alone and in combination with phosphodiesterase type 5 (PDE-5) inhibitors in the treatment of ED associated with LUTS/BPH. Epidemiological studies clearly show that an association exists between ED and LUTS/BPH. The severity of LUTS is correlated with the risk for ED. A significant number of LUTS/BPH patients are nonresponsive to the common ED treatment with PDE-5 inhibitors. As smooth muscle contractility is regulated by adrenoceptors in the corpus cavernosum, prostate and detrusor, the alpha-adrenoceptor system may be considered a common pathophysiological mediator in the development of ED and LUTS/BPH. Blockade of alpha-adrenoceptors for the treatment of BPH/LUTS may have the potential of improving sexual function. Conversely, PDE-5 inhibitors may exhibit positive effects in LUTS patients. Pilot studies on combination regimens of alpha-adrenoceptor antagonists and PDE-5 inhibitors have yielded encouraging results in LUTS patients with persistent ED. On the basis of pharmacological and clinical evidence, it is established that the alpha-adrenoceptor system plays an important role in the pathophysiology of ED and LUTS secondary to BPH. Larger trials on the combination of alpha-adrenoceptor antagonists with PDE-5 inhibitors are necessary to develop an integrated treatment approach for BPH/LUTS patients with comorbid ED.     

Long-term efficacy and compliance of intracorporeal (IC) injection for erectile dysfunction following radical prostatectomy: SHIM (IIEF-5) analysis

Baseline and follow-up data from 102 patients using intracorporeal (IC) injection for erectile dysfunction (ED) following RP were retrospectively collected. We compared baseline International Index for Erectile Function (IIEF) questionnaires with the abridged IIEF-5 questionnaires, referred to as the Sexual Health Inventory of Men (SHIM) to determine drug efficacy. The mean presurgery SHIM score was 21.75+/-5.23, which decreased to 4.23+/-3.48 after surgery and increased to 19.46+/-8.78 post-treatment. Overall, 68% (69/102) of patients achieved and maintained erections sufficient for sexual intercourse and 48% (49/102) of patients continued long-term therapy with a mean use of 3.7+/-1.9 y. In all, 52% (53/102) patients discontinued IC therapy. However when excluding patients who switched to oral therapy, had loss of partner or return of normal erections; the compliance to IC injections was 70.6% (71/102). There was no difference in the SHIM analysis between the nerve sparing (NS) and the non-NS or between the types of medications used. IC injections can provide excellent long-term efficacy and compliance in up to 70% of the patients. This study suggests that IC injections are an excellent salvage option in NS patients who fail oral therapy and a first option in patients with non-NS procedures.     

Phosphodiesterase type 5 inhibitors for erectile dysfunction

The cyclic nucleotide signalling pathway mediates the smooth-muscle relaxing effects of nitric oxide necessary for normal erectile function. Down-regulation of this pathway is central to the pathophysiology of many forms of erectile dysfunction (ED), which is often associated with other chronic diseases (e.g. hypertension, type 2 diabetes mellitus) and treatments (e.g. certain drugs, radical prostatectomy). Conversely, selective inhibition of the enzyme that catalyses the degradation of cGMP (phosphodiesterase type 5, PDE-5) promotes erectile responses to sexual stimulation. The successful launch and commercialization of the selective PDE5 inhibitor (PDE5I) sildenafil transformed the treatment of ED, not only by providing an effective, well tolerated oral ED therapy, but also by fostering greater candour about the problem among men. Sildenafil is highly effective in promoting erectile responses across a wide spectrum of severity and causes of ED, including patients with ED that is often refractory to treatment. The recent advent of vardenafil, which has the highest in vitro potency of all available PDE5Is, and tadalafil, which has a prolonged half-life that may enable couples to have sexual activity with less planning, represent further advances. Other PDE5Is offering further potential improvements are under active investigation.     

Common approach to managing lower urinary tract symptoms and erectile dysfunction

The present paper serves as a review of the associations between lower urinary tract symptoms （LUTS） and erectile dysfunction （ED）, with a focus on common and combined pathways for treatment. LUTS and ED are common conditions seen in general urologic practice. Research has started to establish epidemiologic and pathophysiologic links between the two conditions and a strong association confirmed across multiple studies. Men seeking care for one condition should always be interviewed for complaints of the other condition. Proposed common pathways include α-1 adrenergic receptor imbalance, Rho-kinase overactivity, endothelial cell dysfunction and atherosclerosis-induced ischemia. Medical therapy has replaced surgery as the first-line treatment for LUTS in most patients, with the incorporation of α-adrenergic receptor antagonists （α-ARAs） and 5-α-reductase inhibitors （5-ARIs） into everyday practice. Treatment with α-ARAs contributes to some improvement in ED, whereas use of 5-ARIs results in worsened sexual function in some patients. Phosphodiesterase-5 （PDE-5） inhibitors have revolutionized the treatment of ED with a simple oral regimen, and new insights demonstrate a benefit of combined use of PDE-5 inhibitors and α-ARAs. The mechanisms of action of these medications support these observed benefits, and they are being studied in the basic science and clinical settings. In addition, novel mechanisms for therapy have been proposed based on clinical and research observations. The minimally invasive and surgical treatments for LUTS are known to have adverse effects on ejaculatory function, while their effects on erectile function are still debated. Much remains to be investigated, but it is clear that the associations between LUTS and ED lay the foundation for future therapies and possible preventative strategies.     

Emerging concepts in erectile preservation following radical prostatectomy: a guide for clinicians

Radical prostatectomy (RP) is a commonly performed procedure for the management of prostate cancer. While documented oncologic outcome for early stage disease is excellent, functional impairments such as incontinence and erectile dysfunction (ED) are common after the procedure. Recent evidence has implicated cavernous nerve damage and subsequent corporal oxygen deprivation, as well as corporal inflammation, in the pathogenesis of post-RP ED. Targeted therapies such as oral phosphodiesterase-5 inhibitors, mechanical vacuum erection devices, local alprostadil delivery and testosterone replacement (for hypogonal patients) have demonstrated some efficacy in the management of post-RP ED. This review aggregates much of the recent data in support of these therapies and critically reviews them. The article then presents tools to assess patients and partner sexual function to aid in identifying and monitoring post-RP ED. Finally, the article describes a protocol in use at Baylor College of Medicine as a guide toward the development of a protocol for erectile preservation (EP). The purpose of this work is to educate clinicians on emerging concepts in EP and provide an implementable protocol for use in practice.     

Prognostic factors for response to sildenafil in patients with erectile dysfunction.

OBJECTIVE: To assess the clinical efficacy of sildenafil as treatment for erectile dysfunction (ED) the factors associated with treatment failure were investigated. METHODS: Open, prospective study including 244 patients suffering from ED who were evaluated by anamnesis, physical exploration, blood test, dynamic penile color duplex ultrasonography and Sexual Health Inventory for Male (SHIM). The efficacy of sildenafil was assessed by repeating the SHIM 2 months after therapy, independent of the final dose used. Side effects were also recorded. Factors influencing treatment outcome were evaluated by univariate and multivariate statistical analysis. RESULTS: Overall, sildenafil was effective in 56.8% of 213 eligible patients. When the etiologic diagnosis was not included in the multivariate analysis, antecedents of diabetes mellitus, non-nerve-sparing radical prostatectomy and SHIM basal score were selected as predictors of a poor response. In a second analysis including etiologic diagnosis, only SHIM basal score and etiological diagnosis proved to be of prognostic value. Side effects were noticed by 24.4% of patients, none of them being severe. CONCLUSIONS: Sildenafil is a rather effective and well-tolerated treatment for ED. The basal severity of ED and etiological diagnosis are the prognostic factors most significantly associated with treatment outcome.