A 4-year update on the safety of sildenafil citrate (Viagra)

An overview of the history, current strategies, and potential future treatment approaches in erectile dysfunction: a comprehensive review

INTRODUCTION

Erectile dysfunction (ED) is one of the most common urologic problems in men worldwide, with an approximately high incidence rate, significantly affecting patients' quality of life and their sexual partners.

OBJECTIVES

Due to the association of this disorder with essential diseases such as cardiovascular disease and diabetes, its prevention and treatment are vital for overall human physiologic and psychological health. Along with reviewing the history of treatment and current methods, we seek new approaches to curb this issue in the future.

METHODS

In this review, investigations were based on the focus of each section's content or conducted on an ad hoc basis. Searches were performed in Scopus and PubMed.

RESULTS

In recent years, many treatments for ED have been reported besides oral administration of phosphodiesterase 5 inhibitors such as sildenafil and tadalafil (approved by the Food and Drug Administration). Common oral medications, intracavernous injections, herbal therapies (eg, herbal phosphodiesterase 5 inhibitors), and topical/transdermal medications are routine ED treatment approaches. Moreover, some novel medications are innovative candidates for completing ED's treatment protocols: stem cell injection, low-intensity extracorporeal shock wave therapy, platelet-rich plasma injection, gene therapy, amniotic fluid matrices, rho-kinase inhibitors, melanocortin receptor antagonists, maxi-K channel activators (ie, large-conductance calcium-activated potassium channels), guanylate cyclase activators, and nitric oxide donors.

CONCLUSION

Due to the importance of this complicated problem in men's society, a faster course of treatment trends toward new methods is needed to increase efficiency. Combining the mentioned treatments and attentively examining their efficacy through programmed clinical trials can be a big step toward solving this global problem.

Sildenafil in ophthalmology: An update

Sildenafil citrate, a selective oral phosphodiesterase 5 inhibitor, is a widely used drug for erectile dysfunction that acts by elevating cGMP levels and causing smooth muscle relaxation. It also has 10% activity against PDE6, a key enzyme in phototransduction cascade in the retina. Recent ocular imaging developments have further revealed the influence of sildenafil on ocular hemodynamics, particularly choroidal perfusion. Choroidal thickness is increased, and choroidal perfusion is also enhanced by autoregulatory mechanisms that are further dependent on age and microvascular abnormalities. Studies demonstrating high intraocular pressure via a "parallel pathway" from increased choroidal volume and blood flow to the ciliary body have challenged previous concepts. Another new observation is the effect of sildenafil on bipolar cells and cyclic-nucleotide gated channels. We discuss potential deleterious effects (central serous chorioretinopathy, glaucoma, ischemic optic neuropathy, and risks to recessive carriers of retinitis pigmentosa), potential beneficial effects (ameliorate choroidal ischemia, prevent thickening of Bruch membrane, and promote recovery of the ellipsoid zone) in macular degeneration, as well as potential drug interactions of sildenafil.

The Magic Pill: The Branding of Impotence and the Positioning of Viagra as Its Solution through Edutainment

Product placement can be presented through edutainment. A drug such as Viagra is introduced or impotence is branded in movies and TV series in different ways to raise awareness of impotence disorder and Viagra as a solution. This study aims to analyze strategies of framing and branding Viagra and impotence disorder, based on a qualitative method analysis of 40 movies and TV series. Findings show that Viagra is shown as not only for older men but also for young and healthy men. Out of 40 movies and TV series in the study sample, in 14 (32.5%), the age of the target audience ranged from 20 to 40 years, in 12 (31.6%) movies and series, the age of the target audience was over 40, and in 12 (31.6%) movies and series, the target audience was very old (over 70). Viagra is shown as not only treating impotence but is presented as a wonder drug that provides a solution for psychological and social needs. The movies show usage instructions, side effects, and risks, and how to store the drug. We recommend that the viewing audience be educated for critical viewing of movies/series in order to empower viewers and give them tools for their decision-making processes concerning their health.

Alprostadil cream in the treatment of erectile dysfunction: clinical evidence and experience

Erectile dysfunction (ED) is a very common disorder with a deep impact on quality of life on both patients and partners. Several options are available for treating ED: oral pharmacotherapy with phosphodiesterase 5 (PDE5) inhibitors currently represents the first-line option for many patients with ED. Alprostadil, a prostaglandin, has been marketed for many years as a urethral stick and an intracavernous injection for the treatment of ED. It is now available in the form of a cream (Vitaros/Virirec), a noninvasive treatment which combines an active drug (alprostadil, a synthetic prostaglandin E1) with a skin enhancer improving its local absorption directly at the site of action. Alprostadil has a favourable pharmacodynamic profile and is poorly absorbed in systemic circulation, which makes it suitable in a lot of circumstances and results in a reduced risk of adverse effects (AEs). Systemic AEs are reported in only 3% of the treated population. Clinical efficacy has been demonstrated in both phase II and III trials, showing a global efficacy up to 83% with the 300 μg dose in patients with severe ED, significantly better than placebo. Its fast onset of action and lack of interactions with other drugs makes alprostadil cream a possible first-line therapeutic option for some patients with ED: individuals who are reluctant to take systemic treatments or have AEs, patients who do not respond, cannot tolerate, or do not accept PDE5 inhibitor therapy, and patients treated with nitrates. Therefore, this new treatment for ED can be offered to patients and could help address the needs unmet by other treatments.

Avanafil for male erectile dysfunction: a systematic review and meta-analysis

Avanafil, a potent new selective phosphodiesterase type 5 (PDE5) inhibitor, has been developed for the treatment of erectile dysfunction (ED). We carried out a systematic review and meta-analysis to assess the efficacy and safety of this drug for the treatment of ED. A literature review was performed to identify all published randomized, double-blind, placebo-controlled trials of avanafil for the treatment of ED. The search included the following databases: MEDLINE, EMBASE and the Cochrane Controlled Trials Register. The reference lists of the retrieved studies were also investigated. Four publications, involving a total of 1381 patients, were used in the analysis, including four randomized controlled trials (RCTs) that compared avanafil with a placebo. Among the co-primary efficacy end points indicating that avanafil 100 mg was more effective than a placebo were successful vaginal penetration (SEP2) (the odds ratio (OR) =5.06, 95% confidence interval (CI) =3.29–7.78, P< 0.00001) and successful intercourse (SEP3) (OR = 3.99, 95% CI = 2.80–5.67, P< 0.00001). Men randomized to receive avanafil were less likely than those receiving the placebo to drop out due to an adverse event (AE) (OR = 1.48, 95% CI = 0.54–4.08, P = 0.44). Specific AEs with avanafil included headache and flushing, which were significantly less likely to occur with placebo. This meta-analysis indicates that avanafil 100 or 200 mg is an effective and well-tolerated treatment for ED. Compared with avanafil 100 mg, patients who take avanafil 200 mg are more likely to experience headaches.

Comparison of the simplified International Index of Erectile Function (IIEF-5) in patients of erectile dysfunction with different pathophysiologies

BACKGROUND

The simplified International Index of Erectile Function (IIEF-5) is a convenient, reliable and validated diagnostic tool for erectile dysfunction (ED). However, few studies focused on IIEF-5 in ED patients with different pathophysiological causes. ,We aim to compare the IIEF-5 score among ED patients with specific pathophysiologies in this study.

METHODS

The IIEF-5 score of 3,327 ED patients (median age 39 years) was analyzed. The primary causes of ED were determined by comprehensive diagnostic procedures in the urology/andrology clinics in five training hospitals. Patients with uncertain pathophysiologic cause were excluded.

RESULTS

176 patients were excluded, 3151 patients with ED history between 0.5 year and 20 years, were enrolled. The causes of ED was classified as psychogenic (59.2%), vasoculogenic (21.3%), neurogenic (4.1%), anatomical/structural (2.8%), hormonal (7.1%) or drug-induced (5.5%). A significant difference was detected in the median IIEF-5 score between psychogenic ED and organic ED (15 (IQR 13, 17) versus 12 (IQR 9.5, 14.5), P < 0.001). There was no significant difference of IIEF-5 scores among the organic groups (P = 0.073), or between arteriogenic and venogenic groups (13 (IQR 10.5, 15.5) versus 13 (IQR 11-15), P = 0.912 (adjusted α = 0.017)). However, the median IIEF-5 score of those with a mixed vascular cause was the lowest among vasculogenic patients (11 (IQR 8.5-13.5), scores for the three groups: P = 0.003.).

CONCLUSIONS

The IIEF-5 scores of men with psychological ED are higher than those with organic causes, but there is no difference among patients with different organic pathophysiologies. Our data indicate that IIEF-5 is not a definitive diagnostic tool to discriminate the pathophysiological causes of ED.

Systematic review and meta-analysis of the use of phosphodiesterase type 5 inhibitors for treatment of erectile dysfunction following bilateral nerve-sparing radical prostatectomy

Prostate cancer is relatively common cancer occurring in males. Radical prostatectomy (RP) is the most effective treatment for a localized tumor but erectile dysfunction (ED) is common complication, even when bilateral nerve-sparing RP (BNSRP) is performed. Clinical trials have shown varied effectiveness of phosphodiesterase type-5 inhibitors (PDE5-Is) for treatment of post-BNSRP ED, but there remains controversy over the application of this treatment and no formal systematic review and meta-analysis for the use of PDE5-Is for this condition has been conducted. This review was to systematically assess the efficacy and safety of oral PDE5-Is for post-BNSRP ED. A database search was conducted to identify randomized controlled trials (RCTs). The comparative efficacy of treatments was analyzed by fixed or random effect modeling. Erectile function was measured using the International Index of Erectile Function (IIEF), Sexual Encounter Profile (SEP) question-2, 3 and the Global Assessment Question (GAQ). The rate and incidence of adverse events (AEs) were determined. The quality of included studies was appraised using the Cochrane Collaboration bias appraisal tool. Eight RCTs were included in the analyses. PDE5-Is were effective for treating post-BNSRP ED compared to placebo when erectile function was determined using the IIEF score [mean difference (MD) 5.63, 95% confidence interval (CI) (4.26-6.99)], SEP-2 [relative risk (RR) 1.63, 95% CI (1.18-2.25) ], SEP-3 [RR 2.00, 95% CI (1.27-3.15) ] and GAQ [RR 3.35, 95% CI (2.68-4.67) ]. The subgroup analysis could find a trend that longer treatment duration, higher dosage, on-demand dosing, sildenafil and mild ED are associated with more responsiveness to PDE5-Is. PDE5-Is were overall well tolerated with headache being the most commonly reported AE. Our data provides compelling evidence for the use of PDE5-Is as a primary treatment for post-BNSRP ED. However, further studies are required to optomize usage parameters (such as dosage and duration of treatment).

Stiff fingers as an unwanted side effect of intravascular tadalafil gel abuse

The internet provides the public with unregulated access to a wide range of medications. We present the case of a 43-year-old man who purchased oral tadalafil gel on the internet and injected it into his left radial artery. He presented 48 hours after injection with signs of ischaemia distal to the injection site requiring a combination of medical and surgical treatment. This unique case highlights the potential dangers of unregulated access to medication and the consequences of intravascular injection of oral gels.

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.

Optimizing postoperative sexual function after radical prostatectomy

Erectile dysfunction (ED) is one of the complications associated with pelvic surgery. The significance of ED as a complication following pelvic surgery, especially radical prostatectomy (RP), lies in the negative impact that it has on patients' sexual and overall life. In the literature, rates of ED following RP range from 25% to 100%. Such variety is associated with pelvic dissection and conservation of neurovascular structures. Another important factor impacting on postoperative ED is the preoperative erectile function of the patient. Advances in the knowledge of pelvic anatomy and pathological mechanisms led to a refinement of pelvic surgical techniques, with attention to the main structures that if damaged compromise erectile function. These improvements resulted in lower postoperative ED rates and better erectile recovery, especially in patients undergoing RP. Furthermore, surgery alone is not sufficient to prevent this complication, and thus, several medical strategies have been tested with the aim of maximizing erectile function recovery. Indeed it seems that prevention of postoperative ED must be addressed by a multimodal approach. The aim of this review is to give a picture of recent knowledge, novel techniques and therapeutic approaches in order to reach the best combination of treatments to reduce the rate of ED after pelvic surgery.

Couples' reasons for adherence to, or discontinuation of, PDE type 5 inhibitors for men with erectile dysfunction at 12 to 24-month follow-up after a 6-month free trial

INTRODUCTION

The history of treatments for erectile dysfunction (ED) has involved a repeated pattern of uptake, followed by abandonment of the various therapies in the medium term. Even effective and simple to use medications are not necessarily continued; discontinuation rates range between 15% and 60%. Despite the association between partner sexual function and men's use of PDE5, no previous studies have reported any contact with partners of men taking PDE5 for their ED. This study involved both partners in couples followed up at least 1 year after treatment of ED.

AIM

The study sought clarification of factors influencing adherence to, or discontinuation of, oral ED medications from couples. We hypothesized that many factors contribute to decision making about ED medication use at >12 months.

MAIN OUTCOME MEASURES

The main outcome measures of this article were interviews and International Index of Erectile Function-erectile function domain.

METHODS

A total of 155 interviews were conducted seeking details of frequency of usage and preference for the drugs available; reasons for that choice, or for discontinuation of use, were also sought.

RESULTS

Of men interviewed, 71% were using PDE5 at 18 months. Most men interviewed were using the oral medications either 1-2x/week or 1-2x/month. Forty-four percent of men who had decreased their use of the medications reported less need for them. Thirty-four men said the main reason they were using less medication was cost. "Partner issues" from the men's perspective were seldom reported in this study. However, for a number of women, "partner issues" meant a range of problems from separation to alcohol abuse, lack of communication, and lack of confidence, or fear of failure.

CONCLUSIONS

This is the first study to ask couples why they decided to continue or stop using PDE5 when followed up. Female partners provided a different perspective on "partner issues" often cited as reasons for discontinuing PDE5 use. It was also clear that discontinuation did not mean couples were no longer sexually active.

Newer phosphodiesterase inhibitors: comparison with established agents

Erectile dysfunction is defined as the consistent or recurrent inability to attain or maintain penile erection sufficient for sexual performance. Self-reported erectile dysfunction has increased significantly as men seek effective therapy, such as oral phosphodiesterase 5 inhibitors (PDE5i). PDE5i are now the drugs of choice in the initial therapy of erectile dysfunction. This review compares the currently available PDE5i with the second-generation PDE5i, which are soon to be available.

Tolerability and pharmacokinetics of avanafil, a phosphodiesterase type 5 inhibitor: a single- and multiple-dose, double-blind, randomized, placebo-controlled, dose-escalation study in healthy Korean male volunteers

BACKGROUND

Avanafil is a selective phosphodiesterase type 5 inhibitor being developed for the treatment of erectile dysfunction.

OBJECTIVE

This study was conducted to meet Korean regulatory requirements for the marketing of avanafil. To this end, tolerability and pharmacokinetic properties of single and multiple oral doses of avanafil in healthy Korean male volunteers were assessed.

METHODS

A double-blind, randomized, placebo-controlled, parallel-group, dose-escalation study was conducted at the Asan Medical Center (Seoul, Korea). Subjects were randomized to receive either drug or placebo in blocks according to each dose. Subjects were randomly allocated to receive 50-, 100-, or 200-mg tablets of avanafil or placebo once daily for 7 days (avanafil:placebo, 8:2 in each dose group). Tolerability was assessed by monitoring vital signs and results of laboratory tests, 12-lead ECGs, and color discrimination tests. Blood samples of approximately 6 mL were collected in heparinized tubes before and 0.1, 0.33, 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, 8, 12, and 24 hours after drug administration on days 1 and 7. Plasma concentrations of avanafil were measured using LC-MS/MS. Pharmacokinetic parameters of avanafil on days 1 and 7 were determined by noncompartmental analysis and compared among the 3 dose groups.

RESULTS

Of the 32 healthy male subjects initially enrolled, 30 completed the study. The mean (SD) age, height, and weight of the participants were 23.4 (1.7) years, 175.0 (5.4) cm, and 70.3 (8.9) kg, respectively. Adverse events were reported by 20 of 25 subjects (80%) taking avanafil and by 4 of 6 (67%) taking placebo. No serious adverse events were reported, and there were no clinically relevant changes in vital signs, ECG recordings, physical examination findings, or color discrimination test results. All the adverse events resolved spontaneously. Avanafil reached a mean T(max) at 0.33 to 0.52 hour after dosing and then declined, with a mean apparent t1/2 of 5.36 to 10.66 hours. AUC and C(max) were proportional to dose, and the mean accumulation index on day 7 after a single daily dose of avanafil was 0.98.

CONCLUSION

Avanafil was generally well tolerated and had linear pharmacokinetic properties at daily doses of 50 to 200 mg over 7 days in these healthy Korean male volunteers. Korean National Study Registration Number: 3466.

Standards for clinical trials in male sexual dysfunctions

INTRODUCTION

Clinical trials in male sexual dysfunction (MSD) are expanding. Consequently, there is a need for consensus standards in this area.

AIM

To develop an evidence-based, state-of-the-art consensus report on standards for clinical trials in MSD.

METHODS

A literature review was performed examining clinical trials in erectile dysfunction (ED), premature ejaculation (PE), delayed/absent ejaculation, libido disorders/loss of desire, hypogonadism, and Peyronie's disease, focusing on publications published in the last 20 years. This manuscript represents the opinions of eight experts from seven countries developed in a consensus process. This document was presented for peer review and debate in a public forum and revisions were made based on recommendations of chairpersons to the International Consultation on Sexual Medicine.

MAIN OUTCOME MEASURE

Expert opinion was based on the grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate.

RESULTS

According to experience and recent publications in dealing with clinical trials in sexual dysfunction, recommendations have been made for conducting trials in patients with ED, PE, delayed ejaculation, libido disorders, hypogonadism, and Peyronie's disease.

CONCLUSIONS

It is important that future clinical trials are conducted using standards upon which investigators can rely when reading manuscripts or conducting new trials in this field.

Safety of sildenafil citrate: review of 67 double-blind placebo-controlled trials and the postmarketing safety database

AIM

To review special safety topics associated with sildenafil and to document the tolerability of 50- and 100-mg doses, overall and by age, in men with erectile dysfunction (ED).

METHODS

Data were collated from 67 double-blind placebo-controlled (DBPC) trials (> 14,000 men) conducted by the manufacturer and from the manufacturer's postmarketing safety database (39,277 patients). The DBPC data were stratified by dose, starting dose and age (> or = 65 and > or = 75 years). Special safety topics included cardiovascular risk, priapism, non-arteritic anterior ischaemic optic neuropathy (NAION), impaired renal and hepatic function, drug interactions (i.e. nitrates, cytochrome P3A4 inhibitors, other ED therapies and alpha-blockers) and incorrect use.

RESULTS

Sildenafil was well tolerated at a dose of 50 or 100 mg in men with ED, overall, in those aged > or = 65 years, and in those aged > or = 75 years. Analyses of the databases did not reveal any causal link between sildenafil and cardiovascular events, or any new safety risks relating to cardiovascular events, priapism, NAION, hearing loss or drug interactions. In the small number of men with moderate impairment of renal function or hepatic function who were treated with sildenafil in DBPC trials, the safety profile was similar to that in men with no impairment of renal or hepatic function. Overdose with sildenafil was rare in the ED population. No new safety issues, emerging trends or adverse reactions were identified in conjunction with overdose, dependence, abuse or misuse.

CONCLUSION

This collated review confirms generally the good tolerability and established safety profile of sildenafil 50 and 100 mg in men with ED and reveals no new safety issues.

Phosphodiesterase type-5 inhibitor and oxidative stress

Erectile dysfunction (ED) is a common medical condition that affects the sexual life of millions of men worldwide. Numerous physical and psychological factors are involved in normal erectile function, including neurological, vascular, hormonal and cavernous functions. The current therapy for the condition is pharmacological and psychotherapeutic which regulates the erectile function and amplifies the NO-mediated response. The aim of this work is to test the action of three common phosphodiesterase inhibitors: Tadalafil, Sildenafil Citrate and Vardenafil at 0.05 microM on human monocytes, analyzing the expression of iNOS protein and mRNA by Western blot and rt-PCR, and production of NO by conversion of L-(2,3,4,5)-[3H]Arginine to L-(3H) citrulline. We also tested the efficiency of the antioxidant network by spectrophotometer (SOD, CAT, GPx and Gr), under normal conditions and after stimulation with LPS. The results showed an increase in ROS levels, similar for all the molecules with regard to the antioxidant enzymes. In all cases the treatment determines a response to the limited efficiency, arriving at a situation in which phosphodiesterase inhibitors + LPS clearly show oxidative stress.

Long-term inhaled nitric oxide plus phosphodiesterase 5 inhibitors for severe pulmonary hypertension

BACKGROUND

Inhaled nitric oxide (iNO) is a potent pulmonary vasodilator, but therapeutic experience in patients with severe pulmonary hypertension is scarce.

METHODS

Eleven patients with severe pulmonary hypertension, 6 due to pulmonary arterial hypertension and 4 due to chronic thromboembolic disease, were selected for iNO therapy. A phosphodiesterase type 5 inhibitor (PDE5i) was added in cases of clinical worsening. In this study we evaluate the clinical effectiveness and safety of long-term treatment with iNO either alone or combined with a PDE5i.

RESULTS

After 1 month of iNO administration, improvements were observed in World Health Organization functional class, Borg scale (p = 0.003), brain natriuretic peptide levels (p = 0.002) and 6-minute walk test (p = 0.003). After 6 months of treatment, 7 patients had clinical deterioration that was reversed upon adding a PDE5i. One of these patients died in Month 8 and another underwent pulmonary transplantation in Month 9. The clinical condition of the remaining 9 patients was unchanged after 1 year. A second right catheterization showed improvement in mean pulmonary arterial pressure (66 +/- 15 mm Hg to 56 +/- 18 mm Hg; p = 0.01), pulmonary vascular resistance (1,234 +/- 380 dyn/s/cm(5) to 911 +/- 410 dyn/s/cm(5); p = 0.008) and cardiac index (2.0 +/- 0.4 liters/min/m(2) to 2.5 +/- 0.4 liters/min/m(2); p = 0.04). There was no significant increase in methemoglobin, no worsening of pulmonary function and no sudden withdrawal syndrome.

CONCLUSIONS

We suggest that iNO therapy alone or in combination with a PDE5i could be a therapeutic alternative for severe pulmonary hypertension.

Comparative efficacy assessment of tamsulosin vs. tamsulosin plus tadalafil in the treatment of LUTS/BPH. Pilot study

INTRODUCTION

The high incidence of erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) in aging men and the same pathophysiology make probable to treat both disorders with the same treatment. Numerous authors evaluated the actions of PDE5i in improving the LUTS/(benign prostate hyperplasia) BPH.

AIM

To assess the efficacy and safety of tamsulosin 0.4 mg/day vs. tamsulosin 0.4 mg/day plus tadalafil 20 mg/day in patients with LUTS in a crossover design study.

MAIN OUTCOMES MEASURES

International Prostate Symptoms Score (IPSS), IPSS Quality of Life (IPSS-QOL), maximum flow rate (Qmax), post-void residual volume (PVR), International Index of Erectile Function-Erectile Function Domain (IIEF-EF), Global Assessment Quality (GAQ). For the statistical analysis, a Tukey-Kramer multicomparison test was used.

METHODS

A randomized, double-blind, crossover study was conducted from September 2007 to February 2008 in one center. Thirty men, older than 50 years old, with a history of LUTS/BPH of at least 6 months, were randomized into two groups to receive tamsulosin 0.4 mg/day vs. tamsulosin 0.4 mg/day plus tadalafil 20 mg/day for 45 days, and then switched to the other treatment mode for other 45 days.

RESULTS

Twenty-seven patients completed the study. Improvements of IPSS score and IPSS-QOL were significant with both treatments but greater with the drug combination. Both regimens similarly improved the Qmax and decreased the PVR volume from baseline (P < 0.001) with no significant differences between tamsulosin alone vs. tamsulosin and tadalafil (P > 0.05). The IIEF improved with tamsulosin plus tadalafil (P < 0.001) but not with tamsulosin alone (P > 0.05). The GAQ showed that all patients preferred the combination scheme. Both treatments were well tolerated. CONCLUSION; Tamsulosin 0.4 mg/day plus tadalafil 20 mg/day was more effective than tamsulosin 0.4 mg/day alone to improve LUTS and erectile dysfunction and was also well tolerated. Large-scale, randomized, placebo-controlled studies are needed to further assess the long-term safety and effectiveness of these agents in treating LUTS/BPH with or without ED.

Integrating evidence from multiple sources to evaluate post-approval safety: an example of sildenafil citrate and cardiovascular events

OBJECTIVE

Recent high-profile medicine withdrawals have highlighted the complex decision-making process that regulators, pharmaceutical companies, prescribers, and patients must undertake in determining whether a drug has an appropriate benefit-risk balance. Our objective was to analyze the utility of different drug safety data sources and methods, using the experience of sildenafil citrate (Viagra) and post-approval concerns about its potential association with cardiovascular (CV) events (i.e., myocardial infarction [MI] and death) as a case study.

METHODS

We evaluated safety data from three sources: the standard passive surveillance system (i.e., spontaneous reports filed to Pfizer Inc), pooled clinical trial data, and a prospective observational cohort study, the International Men's Health Study (IMHS).

RESULTS

More than 28 000 spontaneous reports were received in the first 7 years after approval. Between 2001 and 2005, the proportion filed by persons other than healthcare professionals (61%) was approximately double the proportion averaged across five other drugs from the manufacturer's safety database. CV events and/or deaths represented 22.0% of reports, and 23% of reported deaths were medically unconfirmed reports made by persons other than healthcare professionals. In contrast, MI and all-cause mortality rates for sildenafil from both the pooled clinical trial data and the IMHS were similar to placebo, despite differences in methods and populations.

CONCLUSIONS

These results suggest that passive surveillance may generate apparent signals of risk, as was the case with sildenafil and CV events. However, to adequately assess the benefit-risk profile of a drug, these signals must be evaluated via other data sources such as clinical trial and epidemiologic studies, as the apparent signal was not supported by more rigorously collected data. Our post-marketing analysis was unable to examine all potential influences of spontaneous reports, and the study data sources (although large for erectile dysfunction studies) were not designed to exclude small CV risks.

Cardiovascular outcomes among sildenafil users: results of the International Men's Health Study

AIM

To assess the incidence of serious cardiovascular disease (CVD) events [i.e. myocardial infarction (MI) and stroke] and all-cause mortality in men with erectile dysfunction (ED) who received prescriptions for sildenafil.

METHODS

The International Men's Health Study (IMHS) was a prospective, observational cohort study of patients with ED and a new or existing prescription for sildenafil. Baseline and follow-up questionnaires provided information on demographics, CVD risk factors and ED. Postevent questionnaires were mailed to patients following possible nonfatal CVD events to collect information related to exposure to sildenafil/ED treatments before the event.

RESULTS

Thirty-five CVD events were reported in 30 patients in the analysis set (n = 3813). The incidence of all-cause mortality, MI and stroke was 0.4, 0.6 and 0.1 per 100 patient-years of observation respectively. Among the six men who reported using sildenafil in the month before a nonfatal CVD event, two reported use in the 24 h before the event.

CONCLUSION

The results of the IMHS support previous reports that ED and CVD are often comorbid and share risk factors.

British Society for Sexual Medicine guidelines on the management of erectile dysfunction

INTRODUCTION

UK primary care physicians are required to follow authoritative endorsed guidelines as part of their terms of service. The major influence on the management of erectile dysfunction in primary and secondary care between 1999 and 2007 has been Department of Health "guidance on good practice," a non-evidence-based document, essentially defining patients who qualify for government-funded treatment.

AIM

To provide clinically based guidelines relevant to UK primary and secondary healthcare professionals in their daily practice.

METHODS

A multidisciplinary panel of seven UK experts including two primary care physicians from the British Society for Sexual Medicine met for two full day meetings between September 2006 and April 2007, with each member allocated to disease areas related to their specialty. Feedback and approval of all sections between panel members was facilitated by the chairman. Source information was obtained from peer reviewed articles, meetings and presentations. Articles were chosen from electronically searching the Cochrane Library, Medline and Embase for randomized controlled clinical trials and graded according to level of evidence.

RESULTS

Patient-reported sexual activity, satisfaction with sexual activity (Male Sexual Health Questionnaire), and treatment expectations; urologists' subjective assessment of the importance given by their patients to ED; the timing they propose for starting ED treatment.

RESULTS

After the second full day meeting in January 2007, the final version was approved by panel members and made available for healthcare professions by download from http://www.bssm.org and from http://www.eguidelines.co.uk

CONCLUSIONS

A comprehensive evidence-based guideline has been developed that is highly relevant for primary and secondary care professionals enabling them to work within the unique requirements of the UK healthcare system.

Sildenafil in the treatment of erectile dysfunction: an overview of the clinical evidence

Erectile dysfunction (ED) is a highly prevalent disease associated with aging as well as with several risk factors including hypertension, heart disease, obesity, dyslipidemia, diabetes, hypogonadism, drugs-related, and pelvic surgery. Many of these factors are components of the metabolic syndrome, a multiplex risk factor for cardiovascular disease (CVD). ED shares common risk factors with CVD. Endothelial dysfunction seems to be the early underlying pathophysiology across both conditions. The efficacy, tolerability and cardiovascular safety of sildenafil has been evaluated in numerous large, randomized, double-blind, placebo-controlled clinical studies in the broad population of men with ED including men with several co-morbid conditions. Sildenafil is effective in several specific patient populations including the difficult-to-treat subpopulations such as diabetes mellitus and after radical prostatectomy. It is associated with rapid onset of action – within 14 minutes for some men – and an extended duration of action for up to 12 hours. Sildenafil improves quality of life and satisfaction for treated men and is well tolerated with a favorable safety profile. New data suggest that sildenafil has beneficial effects in several chronic conditions. It has been approved for the treatment of idiopathic pulmonary hypertension. Numerous articles have suggested that it improves endothelial function and a possible role on premature ejaculation or treatment of lower urinary tract symptoms has been suggested.

How long do patients with erectile dysfunction continue to use sildenafil citrate? Dropout rate from treatment course as outcome in real life

OBJECTIVES

To study the dropout rate for use of sildenafil after initial prescription and during successful treatment to clarify their risk factors.

METHODS

A total of 1036 patients with erectile dysfunction who were treated with sildenafil were analyzed. The dropout rate during successful treatment and its risk factors were assessed using the Kaplan-Meier method and Cox proportional hazards model, respectively.

RESULTS

Thirty-one percent (n = 322) of the patients dropped out after the initial prescription. The cumulative dropout rate during successful treatment at 3 years after starting usage was 48%. A lower International Index of Erectile Function (IIEF-5) score before treatment was a significant risk factor for dropout during a successful treatment course (P < 0.029 by the Cox proportional hazards model).

CONCLUSIONS

Approximately 30% and 50% of the patients dropped out of treatment after the first prescription and at 3-year follow-up, respectively. Adequate initial instruction and long-term follow-up are required even for patients with successful treatment.