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

Audiovisual Sexual Stimulation and RigiScan Test for the Diagnosis of Erectile Dysfunction

Background:

Currently available evaluation criteria for penile tumescence and rigidity have been fraught with controversy. In this study, we sought to establish normative Chinese evaluation criteria for penile tumescence and rigidity by utilizing audiovisual sexual stimulation and RigiScan™ test (AVSS-Rigiscan test) with the administration of phosphodiesterase-5 inhibitor.

Methods:

A total of 1169 patients (aged 18–67 years) complained of erectile dysfunction (ED) underwent AVSS-RigiScan test with the administration of phosphodiesterase-5 inhibitor. A total of 1078 patients whose final etiological diagnosis was accurate by means of history, endocrine, vascular, and neurological diagnosis, International Index of Erectile Function 5 questionnaire, and erection hardness score were included in the research. Logistic regression model and receiver operating characteristic curve analysis were performed to determine the cutoff value of the RigiScan™ data. Then, the multivariable logistic analysis was used in the selected variables.

Results:

A normal result is defined as one erection with basal rigidity over 60% sustained for at least 8.75 min, average event rigidity of tip at least 43.5% and base at least 50.5%, average maximum rigidity of tip at least 62.5% and base at least 67.5%, △tumescence (increase of tumescence or maximum−minimum tumescence) of tip at least 1.75 cm and base at least 1.95 cm, total tumescence time at least 29.75 min, and times of total tumescence at least once. Most importantly, basal rigidity over 60% sustained for at least 8.75 min, average event rigidity of tip at least 43.5%, and base at least 50.5% would be the new normative Chinese evaluation criteria for penile tumescence and rigidity. By multivariable logistic regression analysis, six significant RigiScan™ parameters including times of total tumescence, duration of erectile episodes over 60%, average event rigidity of tip, △tumescence of tip, average event rigidity of base, and △tumescence of base contribute to the risk model of ED. In logistic regression equation, predict value P < 0.303 was considered as psychogenic ED. The sensitivity and specificity of the AVSS-RigiScan test with the administration of phosphodiesterase-5 inhibitor in discriminating psychogenic from organic ED was 87.7% and 93.4%, respectively.

Conclusions:

This study suggests that AVSS-RigiScan test with oral phosphodiesterase-5 inhibitors can objectively assess penile tumescence and rigidity and seems to be a better modality in differentiating psychogenic from organic ED. However, due to the limited sample size, bias cannot be totally excluded.

Rehabilitation of the cavernous smooth muscle in patients with organic erectile dysfunction

This study aimed at assessing the effect of regular use of intracorporeal injection (ICI), sildenafil citrate and vacuum constriction device (VCD) on cavernous smooth muscle and erectile activity. One hundred and sixty-five patients with organic erectile dysfunction were investigated for 3 months. The patient and his partner were classified prospectively after proper counselling: group I (n = 56) received ICI twice per week; group II (n = 55) received sildenafil 100 mg twice per week; and group III (n = 54) used VCD twice per week. Duplex ultrasound was carried out before and after treatment, and then, the patients were followed up for a month to assess the resumption of unaided erection. The results showed that there was significant improvement in mean peak systolic velocity (PSV) and mean cavernosal artery diameter (CAD) at the end of the treatment in all groups, being higher in the ICI group than in the other two groups. Also, the percentage of patients who resumed unaided intercourse were higher in the ICI group compared with the other two groups (17.9%, 9.1% and 3.7% respectively). It is concluded that repeated regular use of ICI, sildenafil or VCD by patients with organic erectile dysfunction has a positive impact on their cavernous blood flow and erectile activity.

Randomized, double-blinded, placebo-controlled crossover trial of treating erectile dysfunction with sildenafil after radiotherapy and short-term androgen deprivation therapy: results of RTOG 0215

INTRODUCTION

Erectile dysfunction (ED) may be the most commonly observed adverse event (AE) associated with the combination of radiation therapy (RT) and androgen deprivation therapy (ADT). A significant number of men are trying phosphodiesterase type 5 inhibitors (PDE5s) such as sildenafil to treat ED, yet sildenafil studies to date shed little light on the response to ED after ADT.

AIM

The purpose of this trial was to evaluate sildenafil in the treatment of ED in prostate cancer patients previously treated with external beam RT and neoadjuvant and concurrent ADT.

METHODS

  In this randomized, double-blinded crossover trial, eligible patients received RT/ADT for intermediate risk prostate cancer and currently had ED as defined by the International Index of Erectile Function (IIEF). Patients were randomized to 12 weeks of sildenafil or placebo followed by 1 week of no treatment then 12 weeks of the alternative. Treatment differences were evaluated using a marginal model for binary crossover data.

MAIN OUTCOME MEASURES

The primary end point was improved erectile function, as measured by the IIEF.

RESULTS

The study accrued 115 patients and 61 (55%) completed all three IIEF assessments. Sildenafil effect was significant (P = 0.009) with a difference in probabilities of erectile response of 0.17 (95% confidence interval: 0.06, 0.29), and 0.21 (0.06, 0.38) for patients receiving ≤ 120 days of ADT. However, as few as 21% of patients had a treatment-specific response, only improving during sildenafil but not during the placebo phase.

CONCLUSIONS

This is the first controlled trial to suggest a positive sildenafil response for ED treatment in patients previously treated with RT/ADT, however, only a minority of patients responded to treatment. ADT duration may be associated with response and requires further study. The overall low response rate suggests the need for study of additional or preventative strategies for ED after RT/ADT for prostate cancer.

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

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

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.

[Prevention and treatment of erectile dysfunction after radical prostatectomy]

Radical prostatectomy is the curative surgical management of organ confined prostate cancer. Erectile dysfunction may follow surgery as the most common complication decreasing the quality of life of the patient. Thanks to spreading PSA screening probability increases to detect prostate cancer in its early stage and so the expected number of surgery is increasing, too. Higher number of operation as well as surgery more frequently performed in younger age calls the attention to the importance of erectile dysfunction and its management. Nowadays the physiology of erectile dysfunction due to radical prostatectomy has been revealed, and as a consequence, the nerve sparing surgery for its prevention is already known. The paper presents the different kind of possible invasive and non-invasive treatments of erectile dysfunction, and surveys their history and effectiveness. The erectile function of patients who underwent radical prostatectomy between 1998 and 2007 at the Department of Urology and Uro-oncological Centre was assessed by IIEF- and MMM questionnaire and letters with questions of habit of medicine taking. The results show that 59% of patients who desire sexual activity are capable of it spontaneously or with medical management.

Effect of hydrogen sulphide-donating sildenafil (ACS6) on erectile function and oxidative stress in rabbit isolated corpus cavernosum and in hypertensive rats

OBJECTIVE To study the effect of the H(2)S-donating derivative of sildenafil (ACS6) compared to sildenafil citrate and sodium hydrosulphide (NaHS) on relaxation, superoxide formation and NADPH oxidase and type 5 phosphodiesterase (PDE5) expression in isolated rabbit cavernosal tissue and smooth muscle cells (CSMCs), and in vivo on indices of oxidative stress induced with buthionine sulphoximine (BSO). MATERIALS AND METHODS Relaxation was studied in an organ bath in response to carbachol and after incubation with interleukin-1beta for 12 h. CSMCs were incubated with tumour-necrosis factor-alpha or the thromboxane A(2) (TXA(2)) analogue, U46619, with or with no sildenafil citrate, ACS6 or NaHS for 16 h. Superoxide formation and the expression of p47(phox) (an active subunit of the NADPH oxidase complex) and PDE5 protein was then assessed using Western blotting. Rats were also treated with BSO (with or with no sildenafil citrate or ACS6) for 7 days; cavernosal cGMP, cAMP, glutathionine and plasma TXA(2) and 8-isoprostane F(2alpha) was measured by enzyme-linked immunosorbent assay. RESULTS ACS6 and sildenafil citrate relaxed cavernosal smooth muscle equipotently; NaHS alone had little effect at up to 100 microm. The formation of superoxide and expression of p47(phox) and PDE5 was reduced by ACS6, sildenafil citrate and NaHS (order of potency: ACS6 > sildenafil citrate > NaHS). The effects of ACS6 were blocked by inhibitors of protein kinase A (PKA) and PKG. In rats treated with BSO, both ASC6 and sildenafil citrate reduced the increased plasma levels of TXA(2) and 8-isoprostane F(2alpha) but increased cGMP, cAMP and glutathionine levels in corpus cavernosum. CONCLUSIONS By virtue of a dual action on PKA and PKG activation, ACS6 not only promotes erection, acutely, but might also have a long-term beneficial effect through inhibition of oxidative stress and downregulation of PDE5.

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

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