Intracavernous alprostadil alfadex (EDEX/VIRIDAL) is effective and safe in patients with erectile dysfunction after failing sildenafil (Viagra)

Erectile dysfunction management after failed phosphodiesterase-5-inhibitor trial: a cost-effectiveness analysis

BACKGROUND

To evaluate the cost-effectiveness of alternate erectile dysfunction (ED) management options after failed first line phosphodiesterase-5-inhibitors (PDE5-I).

METHODS

An empiric, repetitive decision tree analysis model was constructed using literature review and expert clinical judgement. This assessed the expected costs and quality adjusted life years (QALYs) of decision alternatives over a 10-year period. The model incorporated interventions including alternate PDE5-Is, intracorporal injections (ICI) with alprostadil or trimix (alprostadil, phentolamine, and papaverine), and inflatable penile prosthesis placement (IPP) and included respective risks of failure, subsequent interventions, and other complications (including priapism risk). Average model QALY estimates obtained from the literature were as follows: ED =0.56, successful alternate PDE5-I =0.70, successful ICI =0.70, and successful IPP =0.78. Cost data were calculated from a high-volume academic center and published manufacturer data.

RESULTS

Over the 10-year period, IPP placement was the most cost-effective management option per preserved QALY (QALY =7.82, cost =$22,009/10 years) as compared to ICI alprostadil (QALY =8.51, cost =$62,890/10 years), ICI trimix (QALY =8.47, cost =$48,617/10 years) and alternate PDE5-I (QALY =7.73, $52,883/10 years).

CONCLUSIONS

Using expert opinion and published utility, cost, and complication data in a decision analysis, we demonstrated that IPP placement is the most cost-effective ED intervention following failed initial PDE5-I over a 10-year period as compared to alternate treatment options. Such cost-effectiveness outcomes may be used in ED management counseling.

A Review of Economic Evaluations of Erectile Dysfunction Therapies

INTRODUCTION

Erectile dysfunction (ED) is a common and costly urologic condition with increasing prevalence as men age. Cost-effectiveness of ED therapies and whether cost-effectiveness varies for different populations of men remains underexplored.

AIM

To review and summarize available published data on the economic evaluation of ED therapies and to identify gaps in the literature that still need to be addressed.

METHODS

All relevant peer-reviewed publications and conference abstracts were reviewed and incorporated.

RESULTS

There are a number of medical and surgical treatment options available for ED. The economic evaluation of phosphodiesterase-5 inhibitors, particularly sildenafil, has been well described. However, minimal research has been conducted to assess the cost-effectiveness of intracavernosal injections, intraurethral suppositories, penile prosthesis surgery, vacuum erection devices, and other emerging therapies in men with different causes of ED.

CONCLUSION

Available economic evaluations of ED therapies are dated, do not reflect present-day physician, pharmaceutical, and device costs, fail to account for patient comorbidities, and may not be generalizable to today's ED patients. Substantial research is needed to evaluate the cost-effectiveness of ED treatments across different patient populations, countries, and reimbursement systems. Rezaee ME, Ward CE, Brandes ER, et al. A Review of Economic Evaluations of Erectile Dysfunction Therapies. Sex Med Rev 2019;8:497-503.

Topical alprostadil (Vitaros©) in the treatment of erectile dysfunction after non-nerve-sparing robot-assisted radical prostatectomy

OBJECTIVE

The aim of the study is the evaluation of the efficacy and safety of the treatment with topical alprostadil (Vitaros^©) in post-robot assisted radical prostatectomy (RARP) rehabilitation therapy of patients with erectile dysfunction (ED).

METHODS

Seventy-four patients were enrolled and underwent non-nerve-sparing RARP.

INCLUSION CRITERIA

age <75, preoperatively International Index of Erectile Function (IIEF-5) >16, erection hardness score (EHS) ⩾2, weekly sexual intercourse ⩾1, affirmative answers to Sexual Encounter Profile Question (SEP-Q) 2 and SEP-Q3, Charlson Comorbidity Index (CCI) ⩽5, Eastern Cooperative Oncology Group (ECOG) performance status ⩽1, no moderate/severe cardiovascular disease.

RESULTS

Vitaros was administered ⩾2 twice a week. At month 6, the IIEF-5 decreased from 20.5 preoperative to 18.1 post-treatment. EHS score decreased from a mean of 3.3 to a mean of 3.0. The quality of life score decreased from an average of 5.1 to 2.3. Weekly sexual intercourse decreased from an average of 2.1 to 1.7. Six patients dropped out; 89.7% patients showed a positive SEP-Q2 and 77.8% a positive SEP-Q3. All patients responded positively to Global Assessment Questions (GAQ)-1 and 97% to GAQ-2. Of all 68 analyzed patients, 13 (17.6%) switched to intracavernous injection therapy.

CONCLUSIONS

In conclusion, Vitaros may become a viable alternative to common injective therapies in well-selected patients after RARP.

Erectile function after treatment for rhabdomyosarcoma of prostate and bladder

INTRODUCTION

Rhabdomyosarcoma (RMS) accounts for 5% of all pediatric tumors; 15-20% of these tumors are located in the urogenital tract, mostly originating from the prostate or bladder. In the light of the steadily improving prognosis for patients with RMS through interdisciplinary-multimodal study protocols with 60-70% long-term survivors, non oncological aspects such as erectile function (EF) have become increasingly important. The aim of this study was to evaluate EF in patients having undergone treatment for RMS of the bladder and prostate.

DESIGN

The medical records of 24 male patients having undergone surgical treatment for pelvic RMS between 1975 and 2014 were reviewed, and follow-up was obtained. Erectile function was determined using the Self-Estimation Index of Erectile Function-No Sexual Intercourse (SIEF-NS) and the Erection Hardness Scale (EHS). Potential prognostic factors were evaluated in respect to their impact on EF.

RESULTS

Thirteen patients were included in the study (median age 20 years). Median follow-up period was 12.7 years (1.09-39.85). All patients completed the EHS; nine patients completed the SIEF-NS. All three patients with preserved erectile function (EHS = 4) showed a score indicating no or minimal impairment on sexual function on SIEF-NS (median 33). None of these patients had undergone external radiotherapy, and radical cystoprostatectomy had been performed before the third year of life in two out of three. The remaining patients had erectile dysfunction (EHS = 0). Three patients had an unsatisfying treatment attempt with sildenafil. Seven patients, including all with failures of oral PDE-5-inhibitors, were successfully treated with intracavernous injection of Alprostadil (Summary Table).

DISCUSSION

This was the largest study, to date, evaluating erectile EF in patients treated for RMS of the bladder or prostate. EF was preserved in some patients, despite aggressive treatment modalities. Patients affected by erectile dysfunction after therapy showed limited response to PDE-5 inhibitors, but even after failure of the latter, an intracavernous injection of Alprostadil showed a significant improvement in EHS and SIEF-NS. Limitations of the study included the retrospective nature, small sample size, and heterogeneity of underlying disease, stage, and treatment modalities used.

CONCLUSIONS

The results suggested that in a subset of patients, EF was preserved after radical surgical treatment of RMS, especially in young boys. Intracavernous injection of Alprostadil was effective, even after failure of PDE-5-inhibitors, and should be offered to patients without spontaneous erections, whereas PDE-5-inhibitors appeared to be largely ineffective. External radiation therapy appeared to have a negative impact on EF.

Clinical use of alprostadil topical cream in patients with erectile dysfunction: a review

Erectile dysfunction (ED) is a common and debilitating disorder seen in over 50% of men older than 70 years. Oral phosphodiesterase type 5 (PDE5) inhibitors are the mainstay of treatment for ED, but cannot be used by a significant subset of patients due to systemic side effects and drug-drug interactions. Second-line therapy may include intracavernosal therapies, but are associated with poor compliance due to their invasive nature. Alprostadil has a mechanism of action different from that of PDE5 inhibitors. Clinical trials have shown topical alprostadil cream to be effective, increasing the erectile function (EF) score of the International Index of EF by up to 13 points from baseline. It has also proven to be safe and well tolerated, with mild-to-moderate and transient treatment-related adverse events that are generally localized to the application site. Topical alprostadil cream is a safe and effective second-line therapy for ED, indicated for those who cannot tolerate, or are not satisfied with, oral PDE5 inhibitor therapy.

Pharmacogenetics of erectile dysfunction: navigating into uncharted waters

Sildenafil and other PDE-5 inhibitors have revolutionized erectile dysfunction (ED) treatment. However, a significant number of patients do not respond or present adverse reactions to these drugs. While genetic polymorphisms may underlie this phenomenon, very little research has been undertaken in this research field. Most of the current knowledge is based on sildenafil, thus almost completely ignoring other important pharmacological therapies. Currently, the most promising genes with pharmacogenetic implications in ED are related to the nitric oxide and cGMP pathway, although other genes are likely to affect the responsiveness to treatment of ED. Nevertheless, the small number of studies available opens the possibility of further exploring other genes and phenotypes related to ED. This article provides a comprehensive overview of the genes being tested for their pharmacogenetic relevance in the therapy of ED.

Vacuum erection devices revisited: its emerging role in the treatment of erectile dysfunction and early penile rehabilitation following prostate cancer therapy

INTRODUCTION

Vacuum erection devices (VEDs) are becoming first-line therapies for the treatment of erectile dysfunction and preservation (rehabilitation) of erectile function following treatment for prostate cancer. Currently, there is limited efficacy of the use of phosphodiesterase type 5 inhibitors in elderly patients, or patients with moderate to severe diabetes, hypertension, and coronary artery disease.

AIM

The article aims to study the role of VED in patients following prostate cancer therapy.

RESULTS

Alternative therapies such as VED have emerged as one of the primary options for patients refractory to oral therapy. VED has also been successfully used in combination treatment with oral therapy and penile injections. More recently, there has been interest in the use of VED in early intervention protocols to encourage corporeal rehabilitation and prevention of postradical prostatectomy veno-occlusive dysfunction. This is evident by the preservation of penile length and girth that is seen with early use of the VED following radical prostatectomy. There are ongoing studies to help preserve penile length and girth with early use of VED following prostate brachytherapy and external beam radiation for prostate cancer. Recently, there has also been interest in the use of VED to help maintain penile length following surgical correction of Peyronie's disease and to increase penile size prior to implantation of the penile prosthesis.

CONCLUSION

VEDs can be one of the options for penile rehabilitation after prostate cancer therapy.

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.

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.

Different hemodynamic responses by color Doppler ultrasonography studies between sildenafil non-responders and responders

AIM

To determine if there are different penile hemodynamic patterns between sildenafil non-responders and responders by using color Doppler ultrasonography.

METHODS

A total of 69 erectile dysfunction (ED) patients aged 22-79 years were enrolled into the present study. Thirty-eight (55.1%) men with ED who did not respond to four attempts of treatment with 100 mg sildenafil after re-education were classified as sildenafil non-responders. A combination of three vasodilator drugs, 1.25 mg papaverine, 0.4 mg phentolamine and 5 mg prostaglandin E1, was given by intracavernous injection before penile Doppler ultrasonography was carried out. The erectile response to intracavernous injection and vascular parameters including peak systolic velocity (PSV), resistance index (RI), end diastolic velocity (EDV) and cavernosa artery diameter (CD) were measured and the results between sildenafil non-responders and responders were compared.

RESULTS

No statistical difference in vascular parameters measured by Doppler ultrasonography studies between non-responders and responders was noted. Sildenafil non-responders had a poorer penile rigidity response to intracavernous injection than responders (P < 0.05). Among patients with adequate PSV (>or=30 cm/s) and abnormal EDV (> 5 cm/s), individuals in the non-responder group had fewer positive responses to intracavernous vasodilator injection than in the responder group (35.3% vs. 72.2%, P < 0.05). Advanced age and comorbidity with diabetes mellitus were significantly associated with sildenafil non-response (P < 0.05).

CONCLUSION

Sildenafil non-responders were characterized by a poorer penile rigidity response to intracavernous injection and had an associated impaired veno-occlusive mechanism. Advanced age and comorbidity with diabetes mellitus were two common factors associated with non-response.

Management of sildenafil treatment failures

PURPOSE OF REVIEW

Although oral type 5 phosphodiesterase inhibitors are considered as first-line therapy for the majority of causes of erectile dysfunction, because of their high efficacy, ease of use, and acceptable safety profile, there are some who fail to respond, mainly because of end-organ failure. This communication reviews the management of sildenafil failures in light of recent advances.

RECENT FINDINGS

Sildenafil failures can be attributed to either lack of efficacy or side effects; issues may involve the physician, patient, and his partner. Physicians may contribute to sildenafil failure and discontinuation because of inadequate instructions, lack of adequate follow-up, suboptimal dosing, lack of adequate trial, and insufficient clarification about safety issues. Studies have demonstrated that progression of endothelial dysfunction and diminished cavernosal smooth-muscle content are recognized organic factors which cause end-organ dysfunction and ultimately treatment failure.

SUMMARY

Proper counseling, medication optimization, and modifying associated risk factors can provide success in men who had initially failed sildenafil therapy for erectile dysfunction. Other treatment modalities that may be considered when sildenafil failure occurs include vacuum devices, intraurethral, and intracavernosal administration of vasoactive drugs alone or combined with sildenafil. Penile prosthesis implantation is considered as a last resort, if all first-line and second-line therapies fail.

Prospective, Randomized, Open‐Label, Fixed‐Dose, Crossover Study to Establish Preference of Patients with Erectile Dysfunction after Taking the Three PDE‐5 Inhibitors

INTRODUCTION

We conducted a prospective, randomized, open-label, fixed-dose preference study, with a crossover design, using sildenafil, vardenafil, and tadalafil.

AIM

To assess patient preference for sildenafil (100 mg), vardenafil (20 mg), and tadalafil (20 mg) for the treatment of erectile dysfunction. Secondary objectives included finding out whether patients would follow treatment with a second or third option, in the event that the preferred drug was not available, and to assess side effects.

MAIN OUTCOME MEASURES

Patient preference for any treatment, and evaluation of the elements that patients would assess when choosing one of these drugs.

MATERIAL AND METHODS

Sildenafil (100 mg), vardenafil (20 mg), and tadalafil (20 mg) were taken at least six times over a period of 45-60 days with a washout period of 7 days. A total of 132 patients were enrolled to achieve a valid sample of 90 cases (15 per randomized group, total of six groups). Enrolled patients had mild to moderate erectile function.

RESULTS

The International Index of Erectile Function (IIEF) score improved from baseline and was statistically significant in all cases (P < 0.0001). When we compared the IIEF scores, we found a statistically significant difference between tadalafil and vardenafil (P = 0.0002) favoring the former; similar results were obtained with the Erectile Dysfunction Inventory for Treatment Satisfaction (EDITS) Questionnaire (P = 0.000075). We also found a significant difference (P = 0.012) between tadalafil and sildenafil, again in favor of the former. In assessing drug preference, 25 patients (27.77%) chose sildenafil, 18 (20%) vardenafil, and 47 (52.22%) tadalafil. A total of 94% of patients would be willing to take another drug if the preferred choice was not available. All drugs were well tolerated.

CONCLUSIONS

Although this is a preference study based on subjective elements, statistically significant differences comparing the IIEF score and the EDITS Questionnaire lead us to believe that beyond patients' subjective preference per se, said preference is probably also based on a genuinely superior response to one drug over another.

Erectile Dysfunction Following Radical Retropubic Prostatectomy

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.

Clinical and Duplex US Assessment of Effects of Sildenafil on Cavernosal Arteries of the Penis: Comparison with Intracavernosal Injection of Vasoactive Agents—Initial Experience

PURPOSE

To prospectively evaluate the clinical response and hemodynamic changes in cavernosal arteries after oral administration of sildenafil without and with audiovisual sexual stimulation and to compare those responses with responses from intracavernosal injections of vasoactive agents.

MATERIALS AND METHODS

Institutional review board approval and written informed consent were obtained. Thirteen consecutive patients (age range, 22-77 years; mean, 60.4 years) with erectile dysfunction were evaluated with clinical assessment and cavernosal duplex ultrasonography (US). The patients were examined at two sessions 3 weeks apart. First, each patient received 100 mg of sildenafil citrate orally and was examined 60 minutes later without any sexual stimulation. Each patient then underwent repeat clinical and duplex US assessment after audiovisual sexual stimulation. Three weeks later, the patients underwent identical clinical evaluation and duplex US after intracavernosal injection of a commercially available combination of papaverine, prostaglandin E1, and phentolamine. Clinical and duplex US data (ie, peak systolic velocity [PSV]) were examined by using the Wilcoxon signed rank test for matched pairs.

RESULTS

At rest, the overall mean cavernosal artery PSV was 1.08 cm/sec and remained unchanged after intake of sildenafil without any audiovisual stimulation, with no clinical evidence of erection. With the addition of audiovisual sexual stimulation, eight (62%) of 13 patients had penile congestion or erection, and six (46%) had a PSV greater than 25 cm/sec. With intracavernosal injection of the combination of three drugs, all 13 patients achieved congestion or erection, and 10 (77%) had a PSV greater than 25 cm/sec. Both clinical and duplex US responses to intracavernosal injection were significantly greater than they were to sildenafil with audiovisual sexual stimulation (P = .04 and .003, respectively).

CONCLUSION

Oral sildenafil with audiovisual sexual stimulation led to a significant clinical response and increment in blood flow in the cavernosal arteries. However, more patients responded to intracavernosal injection of the combination of three drugs than to sildenafil, and the clinical response was significantly better.

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

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

An Outbreak of Phialemonium Infective Endocarditis Linked to Intracavernous Penile Injections for the Treatment of Impotence

BACKGROUND

In March 2002, a patient in Tel Aviv, Israel, died of endocarditis caused by Phialemonium curvatum. As part of his therapy for erectile dysfunction, the patient had been trained to self-inject a compound of vasoactive drugs provided by an impotence clinic into his penile corpus cavernosous.

METHODS

We identified the used prefilled syringes as the source of his infection. Similar cases were investigated as a putative outbreak of P. curvatum invasive disease among customers of this impotence clinic. P. curvatum isolates, cultured from samples obtained from the patients and from prefilled syringes, were compared by DNA sequencing of the nuclear ribosomal internal transcribed spacer.

RESULTS

We identified 2 additional customers at the impotence clinic who had P. curvatum endocarditis. In addition, cultures of unused, prefilled syringes and bottles provided by the same clinic to 5 asymptomatic customers tested positive for pathogenic molds (P. curvatum in 4 cases and Paecilomyces lilacinus in 1). All P. curvatum isolates were of a single genetic type that is known only from this outbreak but is closely related to 3 other P. curvatum genotypes associated with pathogenicity in humans.

CONCLUSIONS

P. curvatum is an emerging pathogen that can be readily isolated from blood. We identified an outbreak of P. curvatum endocarditis among men who had erectile dysfunction treated by intracavernous penile injections from contaminated prefilled syringes.

Treatment for Erectile Dysfunction Based on Patient-Reported Outcomes

Erectile dysfunction (ED) is a common medical condition linked both to aging and to many medical conditions such as diabetes mellitus and cardiovascular disease. Although a common condition, treatment for ED has in the past been conducted by a few specialists, mostly urologists and sex therapists. The revolutionary introduction of oral therapy, and the massive amount of research into sexual dysfunction that followed, has led to paradigm shift in the treatment of ED. This is no longer something done by a few for a few; it involves all disciplines of medicine and more patients are being treated by a greater number of physicians. Several medications administered by different routes are available for treating ED but oral pharmacotherapy represents the first-line option. Phosphodiesterase (PDE) type 5 inhibitors are the most widely prescribed oral agents and they have a satisfactory efficacy-safety profile in patients of all categories. An alternative for men who do not respond to PDE5 inhibitors is intracavernosal injection therapy with alprostadil, a prostaglandin analogue. Other alternatives include sublingual apomorphine and intraurethral alprostadil. Both agents have a less satisfactory efficacy profile than PDE5 inhibitors and a low compliance rate. The aim of ED treatment is to restore an erection satisfactory for the sexual needs of the patient. Thus, the patient-reported outcome is the gold standard in efficacy evaluation. There are now three PDE inhibitors available, all with satisfactory efficacy-safety profiles, but with different pharmacokinetic properties. The availability of three different agents has initiated studies aiming to evaluate them regarding patient preference. However, the results are rather conflicting with some studies suggesting that tadalafil has the best patient preference, while others fail to demonstrate a clinically significant difference between the three agents. However, there is a tendency for younger men to choose tadalafil because it gives them a broader window of opportunity, while older men tend to prefer vardenafil or sildenafil. These data could be used when making a decision on which PDE5 inhibitor to prescribe, although another option is to let the patient try all three available agents and make his own choice.

Cyclodextrin-based pharmaceutics: past, present and future

Cyclodextrins are cyclic oligomers of glucose that can form water-soluble inclusion complexes with small molecules and portions of large compounds. These biocompatible, cyclic oligosaccharides do not elicit immune responses and have low toxicities in animals and humans. Cyclodextrins are used in pharmaceutical applications for numerous purposes, including improving the bioavailability of drugs. Current cyclodextrin-based therapeutics are described and possible future applications discussed. Cyclodextrin-containing polymers are reviewed and their use in drug delivery presented. Of specific interest is the use of cyclodextrin-containing polymers to provide unique capabilities for the delivery of nucleic acids.

Treatment program for erectile dysfunction in patients with cardiovascular diseases

The present study assesses the effectiveness of our progressive treatment program for erectile dysfunction in patients with cardiovascular diseases. The study sample included 453 patients aged 36 to 91 years. Therapy in all patients was begun with sildenafil citrate 25 to 100 mg. Those with contraindications, drug adverse effects, or a negative response (erection insufficient for vaginal penetration) were given intracavernous injections of a cocktail of vasoactive drugs (dimix, trimix, or quadmix), followed by the addition of sildenafil citrate to the trimix in case of failure, and then a penile prosthesis. Patients were followed for 2 years; in cases of treatment ineffectiveness during follow-up, drug dosages were increased or a penile prosthesis was suggested. Sildenafil citrate was offered to 417 patients of whom 205 (49.2%) responded positively. The remaining 248 patients received intracavernous injections: 135 (54.4%) had a positive response to the dimix, 85 (75.2%) to the trimix, and 16 (57.1%) to the quadmix. Four of the other 12 patients (0.9%) responded to sildanefil citrate + trimix, and 2 (0.4%) agreed to a penile prosthesis. At the 2-year follow-up of 447 patients, 131 (29.3%) were successfully treated with sildanefil citrate, 92 (20.6%) with dimix, 122 (27.3%) with trimix, 12 (2.7%) with quadmix, and 2 (0.4%) with sildanefil citrate + trimix; 5 patients (1.1%) had a penile implant. Forty-eight patients (10.7%) achieved spontaneous erection, of whom 46 were taking aspirin. Twenty-six patients (5.8%) stopped treatment because of health and family reasons and 9 (2%) had a negative response. Our progressive treatment program for erectile dysfunction has a high success rate in patients with cardiovascular disease: Overall, 98.7% achieved an erection sufficient for vaginal penetration immediately after the trial and 92.2% on follow-up; 10.7% achieved spontaneous erections.

Treatment satisfaction in patients with erectile dysfunction switching from prostaglandin E1 intracavernosal injection therapy to oral sildenafil citrate

Treatment satisfaction, subanalysed by demographic variables, was evaluated in patients switching from successful intracavernosal prostaglandin E(1) (PGE(1)) therapy to oral sildenafil citrate. The validated Erectile Dysfunction Inventory of Treatment Satisfaction questionnaire was administered at the end of PGE(1) therapy and after 12 weeks of sildenafil treatment in a multicentre, open-label study. Men with erectile dysfunction (n=176) who were switched from stable PGE(1) therapy to sildenafil (25-100 mg) were equally satisfied with onset of action, duration of action, and confidence in ability to engage in sexual activity, but expressed greater overall treatment satisfaction with sildenafil (P<0.01), better ease of use (P<0.001), naturalness of erectile process (P<0.001), and intention to continue treatment (P<0.001). Partners (n=32) were overall more satisfied with sildenafil (P<0.05), and their responses correlated with patient satisfaction (r=0.68). Compared with PGE(1) injection, these data suggest that patients may be less likely to discontinue taking sildenafil treatment for their erectile dysfunction.

Switching patients with erectile dysfunction from sildenafil citrate to tadalafil: Results of a European multicenter, open-label study of patient preference

BACKGROUND

Three inhibitors of phosphodiesterase 5 (PDE5) are now available for the treatment of erectile dysfunction (ED): sildenafil citrate, vardenafil, and tadalafil. Pharmacologic differences between these compounds may result in patient preferences for one over another and may influence treatment decisions made by the physician and patient. Therefore, clinical research is needed to investigate whether individual properties of the PDE5 inhibitors play a role in shaping patient preference.

OBJECTIVES

The goal of this study was to determine what proportion of ED patients currently taking sildenafil would, after a period of treatment with tadalafil, elect to resume treatment with sildenafil at the customary dose and what proportion would elect a switch to tadalafil 20 mg for a longer period. The tolerability of both treatments was also investigated.

METHODS

This was a short-term, multicenter, open-label, 1-way crossover trial conducted in Sweden and Italy. Eligible patients included men aged >or=18 years with a minimum 3-month history of ED who had been taking sildenafil at stable fixed doses of 25, 50, or 100 mg as needed for at least 6 weeks and up to 24 weeks. The study consisted of 6 phases: a 1-week screening phase, a 3-week sildenafil assessment phase, a 1-week washout phase, a 6-week tadalafil initiation phase, a 3-week tadalafil assessment phase, and a 6-month extension phase, during which patients received their treatment of choice free of charge. The primary outcome measure was the proportion of patients electing to take sildenafil or tadalafil during the extension phase.

RESULTS

Of 155 men enrolled, 147 (97.8%) completed the assessment phases of the trial. Of these 147 men, 133 (90.5%) elected to receive tadalafil in the 6-month extension phase and 14 (9.5%) elected to receive sildenafil (P < 0.001). The proportions preferring tadalafil to sildenafil were similar irrespective of age group (>or=50 years, 92%; <50 years, 90%), severity of ED (mild, 95%; moderate, 88%; severe, 96%), etiology of ED (psychogenic, 94%; organic, 91%; mixed, 87%), and sildenafil dose at study entry (50 mg, 90%; 100 mg, 89%). Both medications were well tolerated. The most common treatment-emergent adverse events occurring in >or=2% of patients during the tadalafil assessment phase included headache (4.8%), nasal congestion (4.1%), dyspepsia (3.4%), flushing (2.7%), back pain (2.0%), diarrhea (2.0%), and nausea (2.0%); the most common treatment-emergent adverse events during the sildenafil assessment phase were flusing (7.1%), nasal congestion (6.5%), headache (4.5%), and nasopharyngitis (3.2%).

CONCLUSIONS

In this short-term, open-label study, patients who were currently taking sildenafil for ED and then received tadalafil preferred to continue oral therapy with tadalafil over sildenafil by a ratio of approximately 9:1. Although the study sought to mimic the experience of actual patients receiving treatment for ED, the results are subject to potential limitations due to the design of the study, which included differences in dosing instructions and dosages for sildenafil and tadalafil. Both sildenafil and tadalafil were well tolerated.

The ageing male and erectile dysfunction

Erectile dysfunction is common in the ageing man and reliable therapies are needed. The pathophysiology of erectile dysfunction in this group mainly includes chronic ischaemia, which triggers the deterioration of cavernosal smooth muscle and the development of corporeal fibrosis. Assessing the ageing man with erectile dysfunction who seeks medical treatment should comprise a thorough medical and sexual history, a systemic and focused physical examination and selected blood tests. Oral drug therapy represents a safe and effective option for most ageing men.

Viability and safety of combination drug therapies for erectile dysfunction

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Long-term effect of sildenafil citrate on erectile dysfunction after radical prostatectomy: 3-year follow-up

OBJECTIVES

To evaluate the long-term effect and safety of sildenafil citrate for the treatment of erectile dysfunction after radical prostatectomy (RP).

METHODS

The study consisted of 91 patients with erectile dysfunction from our institution who received oral sildenafil citrate after RP. We surveyed these patients using a self-administered questionnaire during the first year of sildenafil citrate use to determine treatment satisfaction, patient compliance, and safety. Those who had responded positively to the drug were surveyed again 3 years later (n = 48). Sildenafil citrate was prescribed at a dose of 50 mg and increased to 100 mg if needed. Data were collected from a self-administered questionnaire using the abridged five-item version of the International Index of Erectile Function questionnaire, referred to as the Sexual Health Inventory of Men, and the Erectile Dysfunction Inventory of Treatment Satisfaction. The patients were stratified according to the type of nerve-sparing (NS) RP procedure they underwent: bilateral NS, unilateral NS, and non-NS.

RESULTS

At 3 years, 31 (71%) of the 43 patients who had returned the second surveys were still responding to sildenafil. Of these 31 respondents, 10 (31%) had augmented their dose from 50 to 100 mg. The dropout rate was 27%; 6 of 12 had discontinued because of the return of natural erections, 5 because of a loss of efficacy, and 1 because his spouse had died. No differences were found in the 1-year and 3-year five-item International Index of Erectile Function (Sexual Health Inventory of Men) and Erectile Dysfunction Inventory of Treatment Satisfaction scores between the NS groups. The most common side effects at 3 years were headache (12%), flushing (10%), and blue or blurred vision (2%). No patient discontinued the drug at 3 years because of side effects.

CONCLUSIONS

The results of this study indicate that the vast majority of patients with erectile dysfunction after RP who initially respond to sildenafil continue to do so at 3 years and are satisfied and compliant with the treatment regimen.

Erectile dysfunction

Erectile dysfunction (ED) is a highly prevalent and often undertreated condition. It may be a symptom of underlying, chronic illness and can have a negative impact on quality of life, psychosocial health, and relationships. The aging of the population, as well as the introduction of new treatment options, such as sildenafil, has led to increased public awareness of this disorder. New oral therapeutic agents are on the horizon. This article provides an overview of the physiology of erection, the pathophysiology of ED, and modern patient evaluation. Management options, including traditional therapeutic approaches as well as the new generation of oral agents, are also presented.

Pharmacological management of erectile dysfunction

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

The efficacy and safety of a topical alprostadil cream, Alprox-TD, for the treatment of erectile dysfunction: two phase 2 studies in mild-to-moderate and severe ED

In two multicenter, placebo controlled, phase 2 studies, patients with mild-to-moderate (n=161, Study 1) or severe (n=142, Study 2) erectile dysfunction (ED) were randomized to receive placebo, 0.05, 0.1, or 0.2 mg (Study 1) or placebo, 0.1, 0.2, or 0.3 mg (Study 2) of topically applied alprostadil (containing a proprietary skin permeation enhancer). The primary efficacy end point in both studies was the change in erectile function (EF) score from baseline to final visit. The changes from baseline for EF scores were -0.8+/-1.1, 1.8+/-1.1, 0.7+/-1.2, and 3.7+/-1.2 (P<0.01; Study 1) and 2.7+/-1.3, 6.29+/-1.4, 6.49+/-1.5, and 9.44+/-1.5 (P<0.001; Study 2) for ascending dose groups in each study. Topical alprostadil was well tolerated with the most common adverse event being urogenital pain. These results suggest this topical alprostadil formulation may be a potentially useful agent for the treatment of ED.

Recent advances in the treatment of erectile dysfunction in patients with diabetes mellitus

OBJECTIVE

To present current information on the pathogenesis of and available therapeutic options for erectile dysfunction (ED) in patients with diabetes.

METHODS

We provide a detailed review of the following topics: (1) peripheral and central neurotransmitter pathways involved in the penile erectile process (for example, nitric oxide, acetylcholine, vasoactive intestinal polypeptide, and prostaglandin E(1)), (2) pathogenesis of ED in patients with diabetes (vascular insufficiency, endothelial dysfunction, and autonomic neuropathy), (3) currently available treatment options for ED and their advantages and disadvantages, (4) potential new avenues for future research, and (5) the possibility of preventive treatment.

RESULTS

Clearly a need exists for effective treatment options for ED in patients with diabetes. Because the development of ED in patients with diabetes is often caused by several interrelated mechanisms, including vascular disease, endothelial dysfunction, autonomic neuropathy, hormone imbalance, and certain medications, a thorough understanding of the various pathways involved in penile erection and their modulation in diabetes is essential for physicians to design an effective treatment plan. Interventions that modulate the erectile pathway at different points include therapies that enhance the erectile mechanism (amplification of the nitric oxide pathway), inhibit the detumescence mechanism, or affect the final common pathway by augmenting smooth muscle relaxation. Oral therapy, intracavernosal injections, transurethral pellets, combination therapy, and surgical procedures are available treatment strategies.

CONCLUSION

Despite the availability of many treatment options for ED, early intervention and prevention (by such measures as improved glycemic control and general reduction of associated risk factors) should be emphasized because many of the diabetes-related complications leading to ED are irreversible.

Acceptance, efficacy and preference of Sildenafil in patients on long term auto-intracavernosal therapy: a study with follow-up at one year

PURPOSE

To assess the acceptance, long term efficacy and preference of Sildenafil in impotent patients previously on auto-intracavernosal therapy.

MATERIALS AND METHODS

The patients were the 107 men (mean age 58.4 y) on auto-intracavernosal therapy (auto-IC) for more than 6 months (mean duration 32.7 months >12 months in 100) who were consecutively seen within 6 months of the launch of Sildenafil in France. If there was no contra-indications to Sildenafil they were proposed a trial of Sildenafil at home. Following this trial they were given the possibility to change their therapy and were followed for 1 y at 3 months intervals.

RESULTS

Three patients had contra-indications to Sildenafil. Of the remaining 104, 45 (43%) refused the trial, mainly because they were afraid of possible cardiac risks (n=21, including 51% of the psychogenic and mixed patients compared to 8% of the predominantly organic ones). Among the 59 who tried it, Sildenafil gave good results in 46 (78%), including 100% of the predominantly psychogenic and 61.5% of the predominantly organic ones) with minimum effective doses of 25 mg in 7, 50 mg in 18 and 100 mg in 21. It failed in 9 (15%) and gave average results in 4 (penetration with a non fully satisfying erection). There was a clear relationship between the sensitivity to Sildenafil and that to Alprostadil, the vasoactive agent predominantly used for the auto-ICIs. Every 46 patients with good result of Sildenafil elected to continue with this drug, including 3 who used both Sildenafil and auto-ICIs in alternance. Every 4 patients with average results elected to continue with auto-ICI including 1 who also used Sildenafil in alternance. Five of the 50 patients with good or average results were lost to follow-up within 6 months. At the 1 y follow-up visit, 43 of the 45 others were still using Sildenafil, in alternance with auto-ICI in 1. No one reported a decrease in efficacy with time. The 2 patients with average results still in the study were on auto-ICIs.

CONCLUSION

Sildenafil is highly effective in the impotent men previously treated with auto-ICI and its efficacy is maintained at least for 1 y. When tried and effective it is preferred by most men but almost half of our patients refused trying it.

Topical alprostadil cream for the treatment of erectile dysfunction: a combined analysis of the phase II program

OBJECTIVES

To present a meta-analysis of the efficacy and safety data of two recently completed Phase II studies examining a novel alprostadil topical cream for the treatment of erectile dysfunction (ED).

METHODS

Patients (n = 303) with ED of at least 3 months' duration were randomized to receive placebo or 50, 100, 200, or 300 microg alprostadil in two nearly identical 11-dose, multicenter, at-home studies of a novel topical cream containing alprostadil and a proprietary skin permeation enhancer. The primary efficacy endpoint was the change in erectile function domain score from baseline to the final visit. Secondary endpoints included changes in scores for questions 3 and 4 of the International Index of Erectile Function and standard diary analyses. Safety was assessed by analysis of adverse events, changes in laboratory test results, and physical examination findings.

RESULTS

The mean baseline parameters for the erectile function score, ED history, and secondary diagnoses suggested no significant differences among the treatment groups. The changes from baseline to the final visit erectile function scores were 0.98 +/- 0.84, 3.4 +/- 1.3, 3.4 +/- 0.88 (P <0.05), 5.3 +/- 0.92 (P <0.001), and 9.4 +/- 1.43 (P <0.001) for the ascending dose groups. Most secondary efficacy endpoints were significant for the 200 and 300-microg dose groups. Dose-related trends in efficacy were observed. Adverse events were localized to the application site, were of mild or moderate intensity, and were of short duration.

CONCLUSIONS

These results suggest topical alprostadil cream, when combined with a novel dermal permeation-enhancer, to be a potentially useful agent for the treatment of ED.

High dose sildenafil citrate as a salvage therapy for severe erectile dysfunction

The objectives of this study were to evaluate the efficacy and tolerability of high dose sildenafil as a salvage therapy for patients refractory to the maximum recommended dose of sildenafil. Fifty four fully evaluated patients with chronic erectile failure (ED) who had previously failed to respond to a home trial of sildenafil (100 mg) with erections suitable for sexual intercourse were studied. Each man was treated at home with sildenafil at escalating doses of up to 200 mg until either maximal response or intolerable adverse effects occurred. Erectile function was quantified using the erectile function domain of the International Index of Erectile Function (IIEF) before treatment, with sildenafil 100 mg and with maximal dose of sildenafil and a global efficacy question after 4 weeks of treatment. The mean age of the study group was 59.6+/-11.2 y. 13/54 (24%) had arteriogenic ED, 16/54 (30%) had mixed vasculogenic ED, 9/54 (17%) had cavernosal veno-occlusive dysfunction, 11/54 (20%) had post radical retropubic prostatectomy ED and 5/54 (9%) had psychogenic ED. 13/54 (24.1%) responded to sildenafil at a median maximal dose of 200 mg, 4/13 required 150 mg and 9/13 required 200 mg. 41/54 (76%) failed to respond to sildenafil. Mean IIEF question 3 and 4 scores were 1.5 and 1.4 at baseline, 2.2 and 1.9 with sildenafil 100 mg, 2.8 and 2.5 with sildenafil 150 mg and 3.0 and 2.9 with sildenafil 200 mg, respectively. After 4 weeks, treatment was regarded as having improved their erections by 37%, 46.3% and 68% of patients with sildenafil 100 mg, 150 mg and 200 mg, respectively. 34/54 (63%) reported adverse effects with maximal dose sildenafil comprising headache (19), facial flushing (32), dyspepsia (14), nasal congestion (11), dizziness (5) and visual disturbances (5). 4/13 (31%) responders refused to continue treatment due to adverse effects.In conclusion, sildenafil at doses of up to 200 mg is an effective salvage therapy for 24.1% of previous sildenafil non-responders but is limited by a significantly higher incidence of adverse effects and a 31% treatment discontinuation rate.

Pharmacological aspects of erectile dysfunction

Erectile dysfunction (ED) is a common problem with a prevalence of approximately 50% in men aged 40 to 70. There are several etiologies for ED including vasculogenic, neurogenic, hormonal and/or psychogenic factors; one-fourth of ED cases can be drug-related. Penile erection involves a complex interaction between the CNS and local factors. It is a neurovascular event modulated by psychological and hormonal factors. Pharmacologically, neural modulation and endocrine status are very important to attaining penile erection. There have been several significant advances for the pharmacologic treatment of ED. Treatments include agents that are not only orally effective, but possess either local or central acting mechanisms of action. Apomorphine, a centrally-acting agent, is effective in the treatment of ED. Sildenafil, another orally effective agent, acts by inhibiting cyclic GMP-specific phosphodiesterase Type V. Testosterone can be effective transdermally. Non-orally active agents include alprostadil and papaverine. Phentolamine and trazodone are effective in selected cases. Some agents can interact with other medications. Several pharmacological agents, some with central-acting mechanisms and some with Iocally-acting vascular effects, are therapeutically useful in the treatment of ED.

Intracavernous injections for erectile dysfunction in patients with cardiovascular diseases and failure or contraindications for sildenafil citrate

The aim of this study was to evaluate the effectiveness of a progressive program for the treatment of erectile dysfunction in patients with cardiovascular disease in whom sildenafil citrate (Viagra) was not an option. The study population included 106 patients selected from 267 with cardiovascular disease. The intracavernous injection program consisted of three protocols of increasingly complex combinations of vasoactive drugs, papaverine, phentolamine, prostaglandin E1 and atropine sulfate. Patients who failed the first protocol were switched to the second, and those who failed the second were switched to the third. A positive response was defined as an erection sufficient for vaginal penetration. A positive response was achieved on protocol I in 61 of the 106 patients (57.5%); protocol II in 32 of the remaining 45 patients (71.1%); and protocol III in seven of the remaining 13 patients (53.8%); the total success rate was 94.3%. These 100 patients were included in the 1-year follow-up, and 90 reported successful coitus at the end of that period: 79 patients (87.8%) with intracavernous injection and 11 (12.2%) without injection. The remaining 10 patients (10%) dropped out of the program, seven (7.0%) for health or marital reasons and three (3.0%) because of treatment failure. We conclude that a progressive program of intracavernous injections of vasoactive drugs may be a good alternative for the treatment of erectile dysfunction in patients with cardiovascular disease.

Neurogenic erectile dysfunction

Penile erection is a neurovascular event modulated by psyche and hormones. Erectile dysfunction (ED) has been classified as psychogenic, arteriogenic, neurogenic, endocrinologic, and cavernosal, based on the organs that are involved in penile erection. Among these types, neurogenic ED may be the most common, probably because a deficiency of neurotransmitters is the final common pathway in many diseases and conditions. This review discusses the physiology, pathophysiology, diagnosis, and treatment of erectile function and dysfunction, as well as strategies for future research.

Neurologic erectile dysfunction

Neurologic erectile dysfunction presents a diagnostic and treatment challenge to the internist and urologist. Multiple chronic disease modalities and traumatic etiologies exist. Education regarding these conditions and a detailed and thorough history and office work-up are the best resources for the clinician. Treatment can follow the model of proceeding from the least to most invasive procedure (process of care), taking into account patient and partner satisfaction. Because the psychology of grief and loss may enter into treatment of some neurologic conditions (e.g., erectile dysfunction after radical retropubic prostatectomy, spinal cord injury, or chronic diseases), a whole-patient approach encompassing psychotherapy is warranted.

Sildenafil citrate: a therapeutic update

BACKGROUND

Since its approval by the US Food and Drug Administration in March 1998, sildenafil citrate has been used by millions of men for the treatment of erectile dysfunction. Recent studies and consensus reports have expanded our understanding of its efficacy, safety, contraindications, and drug interactions.

OBJECTIVE

This paper reviews recent studies of the efficacy of sildenafil, its adverse effects and drug interactions, and socioeconomic factors involved in its use, with a focus on specific patient populations (prostate cancer, diabetes mellitus, ischemic heart disease, spinal cord injuries, neurologic disorders).

METHODS

Clinical studies, case reports, and commentaries and editorials concerning sildenafil published in the international literature between January 1999 and August 2000 were identified through searches of MEDLINE, PREMEDLINE, and International Pharmaceutical Abstracts, using the terms sildenafil, Viagra, and erectile dysfunction.

RESULTS

Sildenafil has demonstrated effectiveness in men with erectile dysfunction associated with prostatectomy, radiation therapy, diabetes mellitus, certain neurologic disorders, and drug therapy (eg, selective serotonin reuptake inhibitors [SSRIs]). It has not been as effective in women with sexual dysfunction, with the exception of SSRI-associated sexual dysfunction. Some disorders unrelated to sexual dysfunction (eg, esophageal motility dysfunction) may also respond to sildenafil. In the general population, sildenafil is considered to have an acceptable tolerability profile; however, patients with moderate to severe cardiovascular disease or those taking nitrate therapy are at increased risk for potentially serious cardiovascular adverse effects with sildenafil therapy. In addition, patients taking drugs that inhibit the cytochrome P450 3A4 isozyme, which metabolizes sildenafil, may experience increased drug concentrations and possible toxicity from normal doses of sildenafil.

CONCLUSIONS

Sildenafil is an effective first-line therapy for erectile dysfunction in men. The decision to prescribe this agent should include such considerations as the cost-risk-benefit balance, patient access, drug distribution pathways, and prescription drug coverage.