Detection Method of Falsified Medicines by Using a Low-Cost Raman Scattering Spectrometer Combined with Soft Independent Modeling of Class Analogy and Partial Least Squares Discriminant Analysis.

There are many reports of falsified medicines that may cause harm to patients. A rapid and simple method of identifying falsified medicines that could be used in the field is required. Although Raman scattering spectroscopy has become popular as a non-destructive analysis, few validation experiments on falsified medicines that are actually distributed on the market have been conducted. In this study, we validated a discriminant analysis using an ultra-compact, portable, and low-cost Raman scattering spectrometer combined with multivariate analysis. The medicines were three types of erectile dysfunction therapeutic tablet and one type of antifungal tablet: tadalafil (Cialis), vardenafil hydrochloride (Levitra), sildenafil citrate (Viagra), and fluconazole (Diflucan), which is sometimes advertised as female Viagra. For each medicine, the authentic standard product and products obtained by personal import via the internet (genuine or falsified) were used. Discriminant analyses were performed on the Raman spectra combined with soft independent modeling of class analogy (SIMCA) and partial least squares discriminant analysis (PLS-DA). It was possible to identify all falsified samples by SIMCA using the standard product model for all four products. Using the PLS-DA using the PLS models of the four standard products, falsified Levitra and Diflucan samples were classified correctly, although some falsified Cialis and all Viagra samples also belonged to the standard class. In this study, SIMCA might be more suitable than PLS-DA for identifying falsified medicines. A spectroscopic module that combines the low-cost Raman scattering spectroscopy with SIMCA might contribute to the rapid identification of falsified medicines in the field.

Phosphodiesterase Type-5 Inhibitor Prescription Patterns in the United States Among Men With Erectile Dysfunction: An Update.

BACKGROUND: While phosphodiesterase type-5 inhibitors (PDE5Is) are highly effective for the treatment of erectile dysfunction (ED) and well tolerated, updated data on prescription patterns have been limited in real-world settings. AIM: To describe men in the United States who are prescribed PDE5Is for ED treatment and to evaluate patterns of initiation, switching, and treatment overlap. METHODS: This retrospective claims study used MarketScan Commercial and Medicare Supplement Databases from January 1, 2010, to December 31, 2015, to identify initial PDE5I claims (index date) for sildenafil, tadalafil, and/or vardenafil. Adults aged ≥18 years with ED were identified between July 1, 2010, and December 31, 2014, allowing for a 6-month preindex and 12-month follow-up period from the index date. OUTCOMES: Outcomes included patient demographics and treatment-related patterns after treatment initiation. RESULTS: A total of 106,206 identified patients met all inclusion criteria. Of these, 51,694, 40,193, and 14,319 had initial claims for sildenafil, tadalafil, and vardenafil, respectively. Mean age was 50.35 years, and comorbidities included dyslipidemia (44.17%), hypertension (43.09%), diabetes (15.32%), and depression (10.61%). More patients (48.67%) initiated on sildenafil than tadalafil (37.85%) or vardenafil (13.48%). Rate of switching was lower in the 60 days after the end of day supply of the initial prescription in the sildenafil cohort (2.71%) compared with the tadalafil (2.81%) and vardenafil (3.88%) cohorts (P < .001 for sildenafil vs tadalafil or vardenafil). Treatment overlap was lower in the sildenafil cohort (0.35%) than in the tadalafil (0.75%) and vardenafil (0.62%) groups (P < .001 for sildenafil vs tadalafil or vardenafil). CLINICAL IMPLICATIONS: These findings provide insight into updated patterns of PDE5I prescriptions in the United States and may aid in clinical decision-making. STRENGTHS & LIMITATIONS: Strengths include the large sample size, long data coverage period, and the real-world nature of the study. Limitations include the retrospective study design, use of data collected with a primary focus of claims, and lack of further details regarding reasons that drive switching. Actual rates of ED and impact on prescription patterns may be underestimated because the claims database only captured patients electing to visit a health-care provider. CONCLUSION: Among men with ED in the United States, rates of switching and treatment overlap were low for all PDE5Is but were found to be the lowest for sildenafil compared with tadalafil and vardenafil. Mulhall JP, Chopra I, Patel D, et al. Phosphodiesterase Type-5 Inhibitor Prescription Patterns in the United States Among Men With Erectile Dysfunction: An Update. J Sex Med 2020;17:941-948.

Falsified vardenafil tablets available online.

It is often reported that falsified medicines have harmful effects on patients both Japan and abroad. In this study, we purchased vardenafil tablets on the internet and investigated their quality and authenticity using visual observations, authenticity investigations, non-destructive tests (handheld NIR and Raman spectroscopy), and quality analyses (active ingredient content and tablet dissolution rate). We used genuine 20-mg Levitra tablets that were sold in Japan and tablets from Bayer AG (Germany) as controls. In April 2015, we obtained 28 samples from 15 websites on the internet. Our authenticity investigations revealed that 11 (40%) were genuine products and 17 (60%) were falsified products. Handheld NIR and Raman results revealed that the falsified products had different spectra to the genuine products. Principal component analysis of the NIR and Raman spectra showed variation among the falsified products. The 11 genuine products were of good quality, and the 17 falsified products were of poor quality. The falsified products contained sildenafil (the active ingredient of Viagra) or tadalafil (the active ingredient of Cialis) instead of vardenafil. Our results show that falsified Vardenafil tablets are sold on the internet and that it is important to prevent illegal internet sales and increase consumer awareness of the presence of falsified medicines.

Self-Regulation in the Pharmaceutical Industry: The Exposure of Children and Adolescents to Erectile Dysfunction Commercials.

CONTEXT: Spending on direct-to-consumer advertising (DTCA) for prescription pharmaceuticals has risen to record levels, five times as much as in 1996 in inflation-adjusted dollars. Major health care provider organizations have called for additional regulation of DTCA. These organizations argue that the negative impact of such advertising outweighs the informational value claimed by the pharmaceutical industry. The industry maintains that further restrictions on DTCA are not warranted because it is successfully self-regulating via "guiding principles" for DTCA as certified by firm executives. METHODS: The authors measured recent industry spending on DTCA and used regression models of Nielsen Monitor-Plus data to assess pharmaceutical firm self-regulation after the public disclosure of noncompliance with industry self-regulatory principles, specifically regarding the exposure of children and adolescents to broadcast advertisements for erectile dysfunction drugs. FINDINGS: Public disclosure of noncompliance with self-regulatory DTCA standards did not bring advertising into compliance. Results demonstrate that firms failed to meet the industry standard during every quarter of the six-year period of this study. CONCLUSIONS: Results support previous research findings that pharmaceutical self-regulation is a deceptive blocking strategy rather than a means for the industry to police itself. Policy recommendations include broadcast restrictions on adult content and deincentivizing DTCA via tax reform.

Risk-benefit assessment of oral phosphodiesterase type 5 inhibitors for treatment of erectile dysfunction: a multiple criteria decision analysis.

BACKGROUND: Erectile dysfunction (ED) is a common male sexual disorder worldwide. Three oral phosphodiesterase type 5 inhibitors (PDE5Is) - sildenafil, tadalafil and vardenafil - are available for treatment of ED. This study quantitatively evaluated the therapeutic efficacy and safety of these medications to assist treatment decision making. METHODS: We used multiple criteria decision analysis (MCDA) to assess the totality of risk-benefit of PDE5Is. We created two models: (i) the overall model included 'overall improvement in erections' and 'any adverse events' and (ii) the detailed model included 'erectile function domain', 'ability for sexual intercourse', 'duration of erection last', 'serious adverse events', 'headache', 'flushing' and 'dyspepsia'. We calculated a synthetic utility for each drug accounting for all of its benefits and risks. RESULTS: Considering the overall risk-benefit, vardenafil had the highest synthetic utility among three medications; in the order of synthetic utilities: vardenafil (0.568), tadalafil (0.478) and sildenafil (0.437). However, when specific risk and benefit criteria were assessed, tadalafil had the highest synthetic utility (0.602) according to the conjoint evaluation (synthetic utility for vardenafil is 0.491 and sildenafil is 0.442, respectively). The sensitivity analysis based on the uncertainties of weight on risks of any adverse events (including serious adverse events and headache) suggested our results were robust. CONCLUSIONS: This study provides a useful approach that comprehensively and systematically assesses and compares the risk-benefit of several treatment alternatives. Our study not only rank treatment alternatives by synthetic utilities based on the risk-benefit balance but also compare specific risk and benefit criteria between these medicines. Our results provide valuable evidence that can guide clinicians and patients in making treatment decisions.

In vitro evaluation of ureteral contractility: a comparative assessment of human, porcine and sheep ureteral response to vardenafil.

OBJECTIVES: Basic science studies of ureteral physiology and pathophysiology are commonly performed on animal ureters due to several limitations associated with human ureteral sampling. In this work we question whether animal ureters are good replicas of human ureteral behavior for pharmacological studies. MATERIALS AND METHODS: Ureteral rings from human, porcine and ovine ureters underwent the same organ bath protocol. After stimulation with KCl, ureters were subjected to different doses of vardenafil. Basic contractility and ureteral response to vardenafil were analyzed. RESULTS: A different pattern of basic contractility was evidenced between species. Vardenafil administration induced a dose-dependent reduction in KCl-induced amplitude increase in human ureters and a dose-dependent reduction in autonomic contractile rhythm of porcine and ovine ureters. Although animal ureters could predict the relaxant response of human samples to vardenafil, its effect would have been overestimated using only animal models. CONCLUSIONS: Human ureteral investigations cannot entirely be replaced by existing animal models since results of the latter will vary significantly according to the tested pharmaceutical agent.

Management of ED under the "severe distress" criteria in the NHS: a real-life study.

INTRODUCTION: The United Kingdom is unusual in that a significant proportion of patients with erectile dysfunction (ED) have their treatment fully reimbursed by the National Health Service (NHS). This may have consequences for the choice of treatment and for compliance with treatment. AIMS: The aim of this study was to evaluate the use and cost implications of phosphodiesterase type 5 inhibitor in an NHS setting. METHODS: Basic demographics and data on ED management for patients treated from January 2000 to April 2011 were obtained from a prospectively accrued database. We reviewed drug usage and costs as well as switching between drugs. Patients were given the choice of all available therapies and were followed up annually. MAIN OUTCOME MEASURES: Switching, compliance, and costs of treating ED under the "severe distress" criteria in the NHS were reviewed for this study. RESULTS: Two thousand one hundred fifty-nine patients qualified for reimbursed therapy. Two hundred twenty-six patients were excluded from further analysis owing to missing data. Patients were followed up on an annual basis. The mean patient age was 60.2 years (min 23, max 90), and the mean follow-up was 50.8 months (min 1, max 127). Six hundred ninety-six were started on sildenafil, 990 on tadalafil, 163 on vardenafil, and 84 on intracavernosal alprostadil. Eighteen percent of patients initially started on the scheme and stopped medication unilaterally. Of the patients, 12.3% changed their medication during follow-up. The cost of drugs increased year by year from £257,100 in 2007 to £352,519 in 2011. CONCLUSIONS: Our real-life observational study shows that in our institution, dropout of therapy is unusual. We hypothesize that this reflects, in part, the reimbursement issue. We also found that switching between drugs was unusual, although there are several possible explanations for that. Although this is a successful system for the patients, the hospital, which bears the costs of medication, is finding this an increasing economic drain.

Monitoring by LC-MS/MS of 48 compounds of sildenafil, tadalafil, vardenafil and their analogues in illicit health food products in the Korean market advertised as enhancing male sexual performance.

More than 46 phosphodiesterase type 5 (PDE5) inhibitor analogues have been found to be present as illegal adulterants in various forms of health food products (powder, tablet, capsule, etc.), thereby placing the health of consumers at risk through product intake. In this study, 164 samples advertised to be effective at enhancing male sexual performance were collected over a 4-year period (2009-2012) from the Korean on-line or off-line market and screened. An LC-MS/MS method was employed to screen for the presence of 48 compounds including sildenafil, tadalafil, vardenafil and their analogues. Method validation established LOQs (0.30-10.00 ng ml(-1) or ng g(-1)) and recoveries (spiked in liquid sample, 84-112%; spiked in solid sample, 83-110%). Most of the illicit products screened were adulterated with 14 of the PDE5 derivatives under examination, including considerable amounts of sildenafil and tadalafil; of the 48 compounds, tadalafil was the most frequent adulterant (42.6%), followed by sildenafil (27.9%). Specifically, tadalafil concentration ranges (mg g(-1)) in the samples collected over the 4-year period were determined as follows: 2.91-52.20 (2009), 4.50-108.10 (2010), 0.37-101.40 (2011), and 0.08-138.69 mg g(-1) (2012). The concentration ranges (mg g(-1)) of sildenafil were also at high levels: 4.90-117.96 (2009), 1.30-369.93 (2010), 0.03-241.77 (2011), and 18.34-297.91 mg g(-1) (2012). The results of screening for PDE5 inhibitor pharmaceuticals as adulterants in illicit health food products are of great significance with respect to the protection of public health and consumer safety.

Prescription opioids for back pain and use of medications for erectile dysfunction.

STUDY DESIGN: Cross-sectional analysis of electronic medical and pharmacy records. OBJECTIVE: To examine associations between use of medication for erectile dysfunction or testosterone replacement and use of opioid therapy, patient age, depression, and smoking status. SUMMARY OF BACKGROUND DATA: Males with chronic pain may experience erectile dysfunction related to depression, smoking, age, or opioid-related hypogonadism. The prevalence of this problem in back pain populations and the relative importance of several risk factors are unknown. METHODS: We examined electronic pharmacy and medical records for males with back pain in a large group model health maintenance organization during 2004. Relevant prescriptions were considered for 6 months before and after the index visit. RESULTS: There were 11,327 males with a diagnosis of back pain. Males who received medications for erectile dysfunction or testosterone replacement (n = 909) were significantly older than those who did not and had greater comorbidity, depression, smoking, and use of sedative-hypnotics. In logistic regressions, the long-term use of opioids was associated with greater use of medications for erectile dysfunction or testosterone replacement compared with no opioid use (odds ratio, 1.45; 95% confidence interval, 1.12-1.87, P < 0.01). Age, comorbidity, depression, and use of sedative-hypnotics were also independently associated with the use of medications for erectile dysfunction or testosterone replacement. Patients prescribed daily opioid doses of 120 mg of morphine-equivalents or more had greater use of medication for erectile dysfunction or testosterone replacement than patients without opioid use (odds ratio, 1.58; 95% confidence interval, 1.03-2.43), even with adjustment for the duration of opioid therapy. CONCLUSION: Dose and duration of opioid use, as well as age, comorbidity, depression, and use of sedative-hypnotics, were associated with evidence of erectile dysfunction. These findings may be important in the process of decision making for the long-term use of opioids. LEVEL OF EVIDENCE: 4.

Phosphodiesterase type 5 inhibitor abuse: a critical review.

Abuse of sildenafil has been reported since its introduction in 1999 and commonly documented in combination with illicit drugs among men and women of all ages. Increased risks of sexually transmissible diseases including HIV have been associated with sildenafil use in men who have sex with men. Recognizing the abuse potential of phosphodiesterase type 5 inhibitors (PDE5), we aim to summarize the current knowledge of this abuse. An investigation of EMBASE, PubMed, the Food and Drug Administration (FDA) website, MedWatch, and search engines was performed to evaluate information regarding sildenafil, tadalafil, and vardenafil abuse. The EMBASE search provided 46 articles fitting the search criteria and evaluation led to 21 separate publications with specific information regarding PDE5 abuse. A PubMed search found 10 additional publications. MedWatch reported 44 separate warnings since 2000, most of which reported contamination of herbal products with active drug components. Few reports of abuse were among the 14,818 reports in the FDA AERS for sildenafil. A search for "internet drug store" revealed 6.4 million hits and of 7000 internet pharmacies identified by the Verified Internet Pharmacy Practice Sites Program (VIPPS) only 4% were in proper compliance. The role internet pharmacies play in counterfeit PDE5 or abuse is not well documented; however based on easy access, direct patient marketing, and low advertised cost it is likely this role is underreported. Currently the best recommendation for providers is to recognize the possibility of abuse and to educate patients on risks of this behavior.

Prevalence and medical management of erectile dysfunction in Asia.

Erectile dysfunction (ED) is an important worldwide health issue that has a significant negative impact on the quality of life and life satisfaction of both the affected individual and his partner. Here we review the prevalence of ED in Asia, associated factors that may influence sexual attitudes and sexual behaviours, and randomized clinical trials (RCTs) of phosphodiesterase-5 (PDE-5) inhibitors to evaluate the clinical efficacy and safety of PDE-5 inhibitors in Asian men. We searched for English-language articles in MEDLINE and PubMed from January 2000 to September 2010. Our results showed that the overall reported prevalence rate of ED in Asia ranged widely, from 2% to 88%. This finding indicates that ED is a common and major health problem in this region. However, sociocultural and economic factors in Asia prevent people from seeking and obtaining appropriate medical care. We found reports on five kinds of PDE-5 inhibitors for the management of ED: sildenafil, vardenafil, tadalafil, udenafil and mirodenafil. The results of RCTs showed that these five PDE-5 inhibitors are more effective than placebo in improving erectile function in Asian men with ED and that these drugs have similar efficacy and safety profiles.

Incremental cost-effectiveness of various monthly doses of vardenafil.

OBJECTIVE: To compare the cost-effectiveness of four, six, and eight doses per month of vardenafil in the context of pharmacy benefit decision making. METHODS: A Markov model was used to estimate the incremental cost-effectiveness of zero, four, six, or eight doses of vardenafil per month in hypothetical cohorts of 60-year-old male veterans with erectile dysfunction. Efficacy values for vardenafil were obtained from the literature, and vardenafil costs were obtained from Veterans Affairs pharmacy data. The analysis was conducted from a third-party payer perspective with a lifetime horizon, and the effect of parameter uncertainty was explored in one-way and probabilistic sensitivity analyses. RESULTS: In the base case analysis, the cost per quality-adjusted life-year gained for four doses of vardenafil per month compared with no therapy was $576. Six doses per month compared with four cost $2585/quality-adjusted life-year gained, and eight doses per month compared with six cost $5169/quality-adjusted life-year gained. In one-way sensitivity analyses of six doses per month compared with four, variation of two parameters caused the incremental cost-effectiveness ratio to cross a willingness-to-pay threshold of $20,000: when the increased utility associated with giving two additional doses/month was less than 0.001 (baseline 0.01) and when the cost per dose increased to $15.00 (baseline $1.69). CONCLUSION: Although four doses per month of vardenafil was the most cost-effective strategy, the use of six or eight doses per month also compares favorably with other accepted medical treatments. The results were stable across a range of inputs and help to support the current Veterans Affairs policy on the number of vardenafil doses provided per month for erectile dysfunction.

Management of erectile dysfunction in general practice.

INTRODUCTION: In recent years, the availability of effective oral pharmacological treatment for erectile dysfunction (ED) has revolutionized its management; however, it is still unclear how everyday clinical practice has changed in response to this evolving scenario. AIM: The aim of this study is to describe general practitioners' (GPs) beliefs and attitudes toward the management of ED. METHODS: Each GP was asked to recruit consecutive men aged >or=18 years and sexually active, with already known erectile problems or with newly diagnosed ED. MAIN OUTCOMES MEASURES: A written questionnaire was used to investigate GPs' sociodemographic characteristics and their beliefs toward the management of ED. RESULTS: Overall, 127 GPs (53.4%) returned the questionnaire and 124 enrolled patients for the study. Only 9.5% of the GPs reported routinely inquiring about ED of patients >40 years of age, whereas 45.7% did it only when the patient raised the problem. GPs' gender and age were associated with their beliefs about ED treatment and referral to specialist care. Overall, 932 patients were enrolled, of whom 38% had newly diagnosed ED. The problem came to light for initiative of patient in 80% of cases, and 84.8% of men were prescribed a treatment. Patients who on their own initiative discussed of their condition had an almost 3-fold increased probability to be treated than those whose GP began the discussion about ED (odds ratio [OR] = 2.6, confidence interval [CI] 95% 1.5-4.5). Patients followed by female physicians were significantly more likely to be referred to a specialist than those followed by male physicians (OR = 3.3, CI 95% 1.4-5.0). CONCLUSIONS: The management of ED has become an integral component of clinical practice in primary care. Nevertheless, barriers in addressing sexual issues still persist. Appropriate training is needed for a proactive approach to ED screening and management in men over 40s.

From Lydia Pinkham to Queen Levitra: direct-to-consumer advertising and medicalisation.

The medicalisation of life problems has been occurring for well over a century and has increased over the past 30 years, with the engines of medicalisation shifting to biotechnology, managed care, and consumers. This paper examines one strand of medicalisation during the last century: direct-to-consumer advertising (DTCA) of pharmaceuticals. In particular, it examines the roles that physicians and the Food and Drug Administration (FDA) have played in regulating DTCA in the US. Two advertising exemplars, the late 19(th) century Lydia E. Pinkham's Vegetable Compound (for 'women's complaints') and contemporary Levitra (for erectile dysfunction) are used to examine the parallels between the patent medicine era and the DTCA era. DTCA re-establishes the direct and independent relationship between drug companies and consumers that existed in the late 19(th) century, encouraging self-diagnosis and requests for specific drugs. The extravagant claims of Lydia Pinkham's day are constrained by laws, but modern-day advertising is more subtle and sophisticated. DTCA has facilitated the impact of the pharmaceutical industry and consumers in becoming more important forces in medicalisation.

Drugs used to treat erectile dysfunction.

Knowledge of the drugs currently approved to treat erectile dysfunction (ED) is important for nurses who care for male patients, especially those men of middle age or older and those who have concurrent health problems or are taking medications that may contribute to ED. This article provides a very basic look at ED and the drugs currently approved and used for treatment. Informed nurses can increase patient understanding of ED, make suggestions for necessary referrals, and help patients and their sexual partners understand the appropriate use and cautions associated with drugs used to treat ED. On the surface, one might question why orthopaedic nurses would need knowledge about drugs currently used to treat ED. However, when one considers that a large proportion of patients in any orthopaedic setting are men, the need for knowledge about the use and safety of these medications becomes a valid component of total patient care. This is an especially important subject today, when media advertising has heightened public awareness of the medications used to treat ED but has not provided much toward a basic understanding about ED or the safe use of the advertised therapeutic agents. Nurses who have some knowledge about ED and the medications used to treat ED are better able to serve as a patient resource for education and referral.

The impact of formulary replacement of sildenafil by vardenafil at a local VA hospital.

The National Veterans Administration (VA) changed its formulary agent for the treatment of erectile dysfunction from sildenafil to vardenafil in January 2006 for economic reasons. The objective of this study was to assess the impact of this formulary change on the patients at a local VA hospital. All non-formulary requests for sildenafil between January 2006 and September 2006 were reviewed. A total of 169 non-formulary requests were made for sildenafil while 7657 patients filled vardenafil prescriptions. Overall, the formulary change from sildenafil to vardenafil appeared to be well tolerated by the vast majority of patients at this local VA hospital. The substantial cost savings to the VA seem to be justified by the minimal adverse effects on men treated for erectile dysfunction.

[Drug counterfeiting--the risk to the public health]. / Podrabianie leków--zagroienie dia zdrowia publicznego.

UNLABELLED: Pharmaceutical counterfeiting and purchasing medicines from illegal distribution channels have become more and more common problem in our country. Different medicines, especially erectile dysfunction drugs are involved. The aim of this study was the qualitative analysis of fake Levitra tablets and the estimation of the risk they bear to potential users. Tablets were secured by the police and delivered to Bayer office in 2006. RESULTS: Trace amount of sildenafil (the active ingredient of Viagra) and not vardenafil (the active ingredient of Levitra) was found in tablets described as "Levitra" (vardenafil). The presence of this substance was discovered by NIR--and Raman spectroscopy. The appearance of tablets and blisters corresponded to the original product. There were no paper boxes and patient information leaflets attached. As prescription medicines erectile dysfunction drugs should be purchased from a pharmacy only. They need to be used under strict medical control.

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

OBJECTIVES: To prospectively investigate whether vardenafil can effectively treat patients for whom sildenafil (100 mg) has failed. The introduction of two new oral phosphodiesterase type 5 inhibitors (tadalafil and vardenafil) raises the question of whether the new agents will permit us to treat sildenafil nonresponders with another oral agent. METHODS: Patients were seen at one institution during a 5-year period. A total of 327 patients complaining of sildenafil-refractory erectile dysfunction underwent intracavernous pharmacologic injection and color duplex Doppler ultrasonography. Subsequently 59 of these men tried vardenafil home dosing. RESULTS: Of the 327 men in whom sildenafil failed, 16% were younger than 50, 21% were 51 to 60, 34% were 61 to 70, and 28% were older than 70 years. The Doppler diagnoses were arterial insufficiency in 154 (47%), mixed vascular insufficiency in 73 (22%), and cavernous venous occlusive disease in 57 (17%). Forty-three men (13%) had normal erectile responses to prostaglandin E1 (10 to 20 microg). Of the 59 men who tried vardenafil, 19% were younger than 50, 17% were 51 to 60, 40% were 61 to 70, and 23% were older than 70 years. The Doppler diagnoses were arterial insufficiency in 28 (42%), mixed vascular insufficiency in 10 (19%), and cavernous venous occlusive disease in 15 (29%). Six men (8%) had normal erectile responses to prostaglandin E1. Only 7 (12%) of the 59 men reported that home vardenafil dosing resulted in successful intercourse. CONCLUSIONS: An appropriate diagnostic evaluation and subsequent treatment algorithm have yet to be established for those for whom phosphodiesterase type 5 inhibitors fail. We found that most sildenafil nonresponders had severe arterial insufficiency and were older, with 62% older than 60 years. Our preliminary experience suggests that only a small percentage (12%) of sildenafil nonresponders can be salvaged with vardenafil.

Erectile dysfunction following radical retropubic prostatectomy: epidemiology, pathophysiology and pharmacological management.

Radical prostatectomy has been the time-honoured and standard treatment option for prostate cancer. Erectile dysfunction (ED) is one of the common quality-of-life issues following radical prostatectomy. The recovery of potency following radical prostatectomy varies from 16% to 86%. Although major modifications in surgical technique appear to be promising, the reported ED rates are still high. The time period required for the recovery of erectile function after surgery varies from 6 to 24 months. During this period of neuropraxia lack of natural erections produces cavernosal hypoxia. This cavernosal hypoxia has been implicated as one of the most important factors in the pathophysiology of ED. Cavernosal hypoxia predisposes to cavernosal fibrosis, ultimately producing venous leak and long-term ED. Interruption of this cascade of events has been the major challenge for physicians. Physicians have several options available for the treatment of ED. However, oral treatment options have quickly become established as first-line treatment options. Sildenafil has been most extensively studied in the radical prostatectomy population. In patients who do not respond to oral therapy alone, standard treatment options (intracavernosal injections, vacuum constriction devices and intraurethral alprostadil) are useful. Use of penile prostheses is one of the oldest treatment options available for the treatment of ED but is used only as a last resort. Initial attempts to promote the earlier recovery of erectile function appear to be promising. However, further confirmatory studies are essential. The roles of gene transfer and growth factors are still in experimental stages. In this review we discuss the epidemiology, pathophysiology and treatment options available for ED following radical prostatectomy.