Early sildenafil dose optimization and personalized instruction improves the frequency, flexibility, and success of sexual intercourse in men with erectile dysfunction

Management of Persistent Erectile Dysfunction after COVID-19 Infection: An 18-Month Follow-Up Case Report

The coronavirus disease 2019 (COVID-19) is an emerging pandemic caused by a novel coronavirus (SARS-CoV-2). Since December 2019 the new virus has spread all over the world and has become a major health problem also because of the public measures that could affect people’s sexual activity. We report a case of a 35-year-old married male admitted to the andrology outpatient clinic in July 2021 because of sudden onset erectile dysfunction (ED). The diagnostic workup showed no risk factor for ED, normal levels of testosterone, increased levels of endothelial dysfunction markers, such as CRP (C-Reactive Protein) and Endothelin-1, and reduced Vitamin D (VD) levels. Dynamic penile duplex ultrasound (D-PDU) revealed dysfunctional penile arterial flow. The five-item International Index of Erectile Function (IIEF-5) and the Short-Form Health Survey (SF-36) showed a reduction in all domain scores. The patient, initially unresponsive to the high dose oral phosphodiesterase 5 inhibitors (PDE-5is), was treated with vitamin-D and then submitted to LI-SWT (low intensity shockwave treatment), with a progressive clinical benefit at the 12-month follow-up. After 18 months, hormone levels persisted in normal ranges, with a consistent reduction in CRP and Endothelin-1. Additionally, IIEF-5, SF-36 and arterial flow significantly improved over the follow-up period. Thus far, the erectile function was restored and the patient is no more treated with PDE-5i.

Contemporary cost-analysis comparison of direct-to-consumer vs. traditional prescriptions of phosphodiesterase-5 inhibitors

After a focused telehealth visit, patients can now access phosphodiesterase-5 inhibitor (PDE5 inhibitor) prescriptions through online direct-to-consumer (DTC) healthcare companies. This study seeks to quantify the cost of DTC PDE5 inhibitor treatment compared to a traditional physician visit and local pharmacy prescription. Two DTC companies, two compounding pharmacies with national reach, three online Canadian pharmacies, and sixteen American pharmacy chains were queried for prices of 90-day regimens of common PDE5 inhibitors. Prices for chains were determined using their publicly available price on GoodRx^® with coupon. Cost of physician visit was determined using 2020 Center for Medicare and Medicaid Services reimbursement for a level 3 new patient visit. For sildenafil 20 mg, a physician visit and local prescription cost a low of $125.45 compared to $144.35 for compounding, $169.34 for Canadian, and $195.00 for DTC. For sildenafil 100 mg, a physician visit and local prescription cost a low of $137.16 compared to $289.35 for compounding, $200.36 for Canadian, and $900.00 for DTC. For tadalafil 5 mg, a physician visit and local prescription cost a low of $125.80 compared to $169.35 for compounding, $195.34 for Canadian, and $720.00 for DTC. For tadalafil 20 mg, a physician visit and local prescription cost a low of $161.00 compared to $289.35 for compounding, $229.00 for Canadian, and $2880.00 for DTC. Thus, local pharmacies, in conjunction with online coupons, consistently provide a markedly less-expensive option for fulfillment of PDE5 inhibitor prescriptions than online DTC services.

The Era of Fake Medicines: Investigating counterfeit medicinal products for erectile dysfunction disguised asherbal supplements

Sales of substandard and falsified medical products (SF) are rising rapidly everywhere around the globe. The wide and easy access to these products is an alarming issue to the global health systems and undermined the health of patients, especially with the thrive of online commerce. To tackle this threat to public health, new ways to access these products should be identified and detection technologies should be strengthened. The overarching aim of this study was to investigate if herbal supplements sold online claiming to be natural alternatives to Viagra® were amongst these SF medical products and how effective different analytical techniques are in providing information about these products. 3 products which claimed to be herbal supplements for men sexual performance were purchased from an e-commerce platform. Two products were received as unregistered generic sildenafil citrate tablets manufactured in India (and thus different to the products information on the website) while one product was received in the same packaging as shown on the website, claiming to be an herbal product. Nevertheless, all products were proven to contain sildenafil citrate, the active pharmaceutical ingredients in Viagra® after the comprehensive analytical tests. The results elucidated that the quality standards for the unregistered generic sildenafil citrate tablets were fulfilled according to the British Pharmacopeia, but the falsified product failed the quality tests and contained approximately 200 mg sildenafil citrate, which is equivalent to 2-fold of the daily maximum dose. Furthermore, physical characterisations, including powder x-ray diffraction and thermal analysis were performed and revealed that the polymorphic forms of sildenafil citrate were different, demonstrating the importance of employing thermal analysis in addition to the conventional analysis techniques for the substandard and falsified medical products. These techniques provided valuable insights into the physical form of the active ingredient in these products. What is more, the ease with which these SF products were obtained and confirmed to be misleading consumers emphasises the need for tighter regulation for e-commerce websites in line with those enforced on online pharmacies.

Sildenafil 4.0-Integrated Synthetic Chemistry, Formulation and Analytical Strategies Effecting Immense Therapeutic and Societal Impact in the Fourth Industrial Era

Sildenafil is a potent selective, reversible inhibitor of phosphodiesterase type 5 (PDE5) approved for the treatment of erectile dysfunction and pulmonary arterial hypertension. Whilst twenty years have passed since its original approval by the US Food and Drug Administration (USFDA), sildenafil enters the fourth industrial era catalyzing the treatment advances against erectile dysfunction and pulmonary hypertension. The plethora of detailed clinical data accumulated and the two sildenafil analogues marketed, namely tadalafil and vardenafil, signify the relevant therapeutic and commercial achievements. The pharmacokinetic and pharmacodynamic behavior of the drug appears complex, interdependent and of critical importance whereas the treatment of special population cohorts is considered. The diversity of the available formulation strategies and their compatible administration routes, extend from tablets to bolus suspensions and from per os to intravenous, respectively, inheriting the associated strengths and weaknesses. In this comprehensive review, we attempt to elucidate the multi-disciplinary elements spanning the knowledge fields of chemical synthesis, physicochemical properties, pharmacology, clinical applications, biopharmaceutical profile, formulation approaches for different routes of administration and analytical strategies, currently employed to guide the development of sildenafil-based compositions.

Practical Approaches to Treat ED in PDE5i Nonresponders

Erectile dysfunction (ED) is a common sexual disorder in adult males and one of the most important factors affecting their quality of life and that of their partners. Although PDE5 inhibitors (PDE5is) are the first choice for improving erectile function, there is a substantial proportion of ED patients, termed PDE5i nonresponders, who do not respond to PDE5is. Because of the lack of effective therapies, these patients always have serious social and psychological problems due to ED, which should be addressed. Here, we review the available literature about ED and PDE5is and propose several strategies for mitigating ED in PDE5i nonresponders.

Real-World Assessment of the Impact of Erectile Dysfunction on Sexual Planning Behavior and Health- and Treatment-Related Outcomes Among Men in 8 Countries

INTRODUCTION

The effect of erectile dysfunction (ED) on sexual planning behaviors and outcomes in men taking phosphodiesterase type 5 inhibitors (PDE5Is) is not well studied.

AIMS

To assess sexual habits, behaviors, and treatment-related outcomes of PDE5I-treated men with ED.

METHODS

This cross-sectional observational study recruited men aged 30 to 70 years with mild-to-severe ED from 8 diverse countries (the United States, the United Kingdom, Italy, Russia, Turkey, Israel, China, and Japan) to complete an approximately 15-minute survey. Differences were evaluated using bivariate analyses, and data were summarized using descriptive statistics.

MAIN OUTCOME MEASURES

Self-reported data were collected for demographics, health characteristics, treatment, sexual habits, ED severity, ED-specific quality of life, and treatment satisfaction.

RESULTS

The survey was completed by 1,575 men. Mean frequency of sexual intercourse was 5.7 times/month. Overall, 87.1% of men always, often, or sometimes planned for sexual activity. Of those planning in advance, 32.8% and 40.6% agreed or strongly agreed that they plan for specific days of the week and times of day, respectively. Sexual planning habits were similar for patients taking short-acting vs long-acting PDE5Is. The most commonly cited reasons for planning sexual activity were needing time to take medication (48.4%), needing to make sure medication has taken effect (43.4%), convenient time for sexual activity (34.9%), and needing the partner's agreement (33.4%). Mean Self-Esteem and Relationship Questionnaire total score was 56.4.

CONCLUSIONS

The differences in ED burden and sexual planning behavior observed across countries were not influenced by the type of PDE5I being taken, suggesting that cultural differences are an important factor when considering types of ED treatment. These findings provide a better understanding of burden, sexual habits, planning behaviors, quality of life, and treatment-related outcomes among PDE5I-treated men with ED in 8 Western and non-Western countries and may aid healthcare providers in selecting optimal treatments. Goldstein I, Giraldi A, Maculaitis MC, Real-World Assessment of the Impact of Erectile Dysfunction on Sexual Planning Behavior and Health- and Treatment-Related Outcomes Among Men in 8 Countries. J Sex Med 2020;8:338-349.

Sexual habits of men with ED who take phosphodiesterase 5 inhibitors: a survey conducted in 7 countries

INTRODUCTION

Western cultural perceptions that favour spontaneous sex may create unrealistic expectations for erectile dysfunction (ED) treatment. Little is known about how users of phosphodiesterase type 5 inhibitors (PDE5Is) plan sexual activity and timing of their preactivity PDE5I ingestion. Because various PDE5Is vary in their duration of action and dosage regimen, this may be an important consideration in selecting the optimal agent for the ED patient.

AIM

To better understand the sexual habits of PDE5I users.

METHODS

Men from 7 countries (Brazil, China, Italy, Japan, Russia, Taiwan, Turkey) were screened online for age, self-reported comorbidities and ED medication use in the prior 3 months. After screening, eligible participants were asked to complete a 7-question, self-administered online survey containing questions regarding sexual habits and behaviours.

MAIN OUTCOME MEASURES

Survey questions focused primarily on advanced planning of sexual intercourse and timing of PDE5I ingestion but also addressed the frequency of sexual intercourse and ED medication use.

RESULTS

Of the 1458 respondents (response rate: 48%; median age: 48 years [interquartile range (IQR), 44-55]), 83% always/sometimes planned a specific time for intercourse in advance; 72% planned a specific time for sexual intercourse up to several hours in advance. Of respondents who planned in advance, more than half planned specific days of the week (55%) and times of the day (60%) for sexual intercourse. The time to sexual intercourse after dosing was ≤1 hour for 70% and ≤4 hours for 96% of men. The median frequency of sexual intercourse was 6 times/month (IQR, 4-10), with ED medication taken a median of 5 times/month (IQR, 3-8).

CONCLUSIONS

Sexual activity is usually planned by ED medication users several hours in advance, and the vast majority are attempting activity within a short time after ingestion of the agent. These data should aid clinicians in the selection of the optimal PDE5I.

Efficacy and Safety of Sildenafil by Age in Men With Erectile Dysfunction

INTRODUCTION

Sildenafil, an oral phosphodiesterase type 5 inhibitor, has been extensively investigated for the treatment of erectile dysfunction in randomized controlled trials.

AIM

To assess the efficacy and safety of sildenafil vs placebo according to age subgroups (<65, 65-74, and ≥75 years) in 11,364 men with erectile dysfunction using pooled data from 48 randomized, double-blinded, placebo-controlled, parallel-group, flexible-dose trials.

METHODS

Most trials had a 12-week treatment duration. The starting sildenafil dose was 50 mg, taken 1 hour before sexual activity, with subsequent adjustment to 100 or 25 mg based on efficacy and safety. Men taking nitrate therapy or nitric oxide donors and men with severe cardiac failure, unstable angina, or recent stroke or myocardial infarction were excluded. Efficacy analyses included all subjects with baseline and at least one postrandomization evaluation. Safety analyses included subjects who received study medication.

MAIN OUTCOME MEASURES

The International Index of Erectile Function and a global assessment question ("Did the treatment improve your erections?").

RESULTS

Mean International Index of Erectile Function scores for question 3 (frequency of penetration), question 4 (maintenance of erections after penetration), and the erectile function domain were statistically significantly improved with sildenafil vs placebo for each age subgroup; orgasmic function, intercourse satisfaction, sexual desire, and overall satisfaction domain scores also were statistically significantly improved with sildenafil vs placebo. The percentage of men reporting improved erections on the global assessment question was statistically significantly higher with sildenafil vs placebo for all age subgroups; the percentage with sildenafil tended to decrease with increasing age (<65 years, 80%; 65-74 years, 69%; ≥75 years, 59%). The most common adverse events with sildenafil were headache and flushing in each age subgroup.

CONCLUSION

Sildenafil is an effective and well-tolerated treatment for erectile dysfunction regardless of patient age, including men at least 75 years old.

Sildenafil improves erectile hardness in Chinese men with erectile dysfunction: a real-life study analyzed on age stratification

OBJECTIVE

To evaluate the clinical efficacy of sildenafil for the improvement of penile erection hardness in erectile dysfunction (ED) patients and to determine the relationship between this improvement in erection hardness and social and psychological functioning.

MATERIALS AND METHODS

From 2007 to 2008, a total of 4507 men diagnosed with ED were enrolled from 46 centers in China; 4039 of these patients were treated with sildenafil and asked to complete the Erectile Function domain of the International Index of Erectile Function, Erection Hardness Score, and Quality of Erection Questionnaire. The patients were divided into 5 groups on the basis of their age (group A: 20-30 years; group B: 31-40 years; group C: 41-50 years; group D: 51-60 years; and group E: >60 years).

RESULTS

A total of 3837 (95.0%) patients completed the entire study. After sildenafil treatment, the vast majority (96.3%) of the men were able to achieve grade 3-4 erection hardness. Patients with a better baseline erection hardness were more able to achieve grade 4 hardness after treatment (P <.001). Comparisons of the Erection Hardness Score improvement before and after treatment between the age-categorized groups also showed that the erection hardness improvement was much greater in men older than 50 years.

CONCLUSION

Sildenafil can help the vast majority of Chinese ED patients achieve grade 3-4 erection hardness. Grade 4 hardness can improve the patients' sexual life to a greater extent than grade 3 hardness. A marked improvement in erection hardness can be achieved in patients older than 50 years.

Improvement in erection hardness and intercourse success with first dose of sildenafil citrate 100 mg

PURPOSE

To determine, in men with erectile dysfunction (ED), the extent of improvement in erection hardness and in the rate of successful sexual intercourse (SSI) during the final intercourse attempt using sildenafil 50 mg compared with the subsequent initial attempt after a dose increase to 100 mg.

PATIENTS AND METHODS

This post hoc analysis used data from two randomized, double-blind, placebo-controlled studies of flexible-dose sildenafil for the treatment of men with ED, who were given sildenafil 50 mg or matching placebo, to be taken as needed before sexual intercourse. After 2 weeks, those with no tolerability concerns were titrated up to 100 mg, forming the subgroup of this analysis. The main outcome measures were event log data, including an Erection Hardness Score (EHS) and a question on SSI ("Did your erection last long enough for you to have successful sexual intercourse?"), for each attempt at sexual intercourse, analyzed by study and treatment group (sildenafil or placebo). Statistical comparisons were conducted by using the Fisher's exact test.

RESULTS

In both studies, the sildenafil group had a larger proportion of EHS4 (completely hard and fully rigid) erections (P < 0.001) and SSI (P < 0.005) compared with the placebo group, both before and after the dose increase. Between the final 50 mg sildenafil dose and the initial 100 mg sildenafil dose, the outcomes improved and significantly so in the larger study.

CONCLUSION

The improved efficacy with sildenafil 100 mg versus 50 mg, which occurs rapidly, suggests that patients should be encouraged to use 100 mg if they are unable to achieve completely hard and fully rigid erections or SSI with the 50 mg dose.

Incidence rate of prostate cancer in men treated for erectile dysfunction with phosphodiesterase type 5 inhibitors: retrospective analysis

The purpose of this study was to determine the incidence rate of prostate cancer among men with erectile dysfunction (ED) treated with phosphodiesterase type 5 inhibitors (PDE-5i) over a 7-year period vs. men with ED of the same age and with similar risk factors who were not treated with PDE-5i. In a retrospective review of electronic medical records and billing databases between the years 2000 and 2006, men with ED between the ages of 50 and 69 years and no history of prostate cancer prior to 2000 were identified. These individuals were divided into two groups: 2362 men who had treatment with PDE-5i, and 2612 men who did not have treatment. Demographic data in each group were compared. During the study period, 97 (4.1%) men with ED treated with PDE-5i were diagnosed with prostate cancer compared with 258 (9.9%) men with ED in the non-treated group (P<00001). A higher percentage of African Americans were treated with PDE-5i vs. those who were not (10.5% vs. 7.1%; P<0.0001). The PDE-5i group had lower documented diagnosis of elevated prostate-specific antigen (10.0% vs. 13.1%; P=0.0008) and higher percentage of benign prostatic hyperplasia (38.4% vs. 35.1%; P=0.0149). Men with ED treated with PDE-5i tended to have less chance (adjusted odds ratio: 0.4; 95% confidence intervals: 0.3-0.5; P<0.0001) of having prostate cancer. Our data suggest that men with ED treated with PDE-5i tended to have less of a chance of being diagnosed with prostate cancer. Further research is warranted.

Hardness, function, emotional well-being, satisfaction and the overall sexual experience in men using 100-mg fixed-dose or flexible-dose sildenafil citrate

The prescribing information for sildenafil citrate (VIAGRA, Pfizer, New York, NY, USA) recommends flexible dosing (50 mg initially, adjusted to 100 or 25 mg based on effectiveness and tolerability) in most men with erectile dysfunction (ED). In many men, however, 100 mg may be the most appropriate initial dose because it would reduce the need for titration and could prevent discouragement and treatment abandonment should 50 mg be insufficient. Results of two previously published double-blind, placebo-controlled sildenafil trials of similar design except for a fixed-dose vs flexible-dose regimen were analyzed. Relative to the flexible-dose, approximately one-third more men were satisfied with an initial and fixed dose of 100 mg. In addition, tolerability was similar, and improvements from baseline in outcomes on validated, ED-specific, patient-reported questionnaires were either similar (erectile function and the percentage of completely hard and fully rigid erections) or greater (emotional well-being and the overall sexual experience). The similarity in outcomes is not surprising given that almost 90% of the men in the flexible-dose trial titrated to 100 mg after 2 weeks. These data suggest prescription of an initial dose of 100 mg for men with ED, except in those for whom it is inappropriate.

Multiple affinity states of cGMP-specific phosphodiesterase for sildenafil inhibition defined by cGMP-dependent and cGMP-independent mechanisms

cGMP-specific phosphodiesterase (PDE5) has become a target for drug development for the treatment of a number of physiological dysfunctions, affected by changes in the cGMP/cGMP-dependent protein kinase (PKG) signaling pathway. PDE5 has two highly homologous regulatory domains, GAF-A and GAF-B. We showed previously that PDE5 could be converted from a low-activity (nonactivated) state to a high-activity state upon cGMP binding to the GAF-A domain with higher sensitivities toward sildenafil (EMBO J 22:469-478, 2003). Here we investigated whether sildenafil sensitivity of PDE5 could be modified by cGMP-independent mechanisms. Individually expressed recombinant GAF-A and GAF-B proteins were tested for their ability to modulate full-length recombinant PDE5 affinity to sildenafil. The GAF-A domain protein had the most dramatic effect on the affinity of the nonactivated recombinant PDE5 for sildenafil, revealing much higher sensitivity to sildenafil inhibition. The apparent affinity for sildenafil increased from the nanomolar range to the picomolar range, providing evidence for the presence of a "super-high" sensitivity state of PDE5 for sildenafil inhibition. In human platelet, higher sensitivity of PDE5 for sildenafil inhibition has been detected after blocking cGMP-binding sites of the GAF-A domain. Thus, our data demonstrate that high sensitivity of PDE5 for sildenafil can be obtained not only through cGMP-induced activation of PDE, but also through cGMP-independent modulation of PDE5 in the nonactivated state, possibly through protein-protein interaction. Furthermore, data suggest that nonactivated PDE5 with "super-high" affinities for sildenafil inhibition may be responsible for therapeutic effects of long-term treatments with low doses of PDE5 inhibitors.

Phosphodiesterase type 5 inhibitors facilitate noncontact erections in male rats: site of action in the brain and mechanism of action

INTRODUCTION

Orally active phosphodiesterase type 5 inhibitors (PDE5i), used in the treatment of erectile dysfunction, facilitate the relaxation of cavernous smooth muscle tissues by reducing the degradation of cyclic guanosine monophosphate.

AIMS

The aims of this article were to determine whether PDE5i facilitate penile erection and male sexual behavior by acting also on the central nervous system and to investigate their mechanism of action at central level.

METHODS

PDE5i (sildenafil, vardenafil, and tadalafil) given intraperitoneally (i.p.) (5 mg/kg and 10 mg/kg), intracerebroventricularly (i.c.v.) (10 microg and 50 microg), or into the ventral tegmental area (VTA) (10 microg) were tested in the noncontact erection test in male Sprague-Dawley rats screened for their ability to display or not display this sexual response. Extracellular dopamine was measured in the dialysate obtained from the nucleus accumbens by intracerebral microdialysis on injection of PDE5i into the VTA. MAIN OUTCOME MEASURES. Noncontact erections were counted after intraperitoneal, intracerebroventricular, or intra-VTA treatment with PDE5i. Extracellular dopamine was measured in the dialysate from the nucleus accumbens when sildenafil or vardenafil was given into the VTA. Results. PDE5i induced a significant increase of noncontact erections in male rats displaying this sexual response following intraperitoneal or intracerebroventricular administration at the highest dose tested. However, both doses significantly increased noncontact erections in male rats not displaying this sexual response. Similar results were found when PDE5i were injected into the caudal VTA. Noncontact erections increased concomitantly to a rise in extracellular dopamine in the dialysate from the nucleus accumbens.

CONCLUSIONS

The results suggest that PDE5i may increase sexual arousal by acting in the central nervous system. This effect may be mediated (at least in part) by the activation of mesolimbic dopaminergic neurons.

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.

Randomized, double-blind, crossover trial of sildenafil in men with mild to moderate erectile dysfunction: efficacy at 8 and 12 hours postdose

OBJECTIVES

To clarify the period of responsiveness to sildenafil.

METHODS

Under a double-blind protocol, men with mild to moderate erectile dysfunction (International Index of Erectile Function [IIEF] Erectile Function domain score, 11 to 25) were randomized to sildenafil (100 mg) or placebo and attempted intercourse 8 hours (range, 7 to 9 hours) postdose (first 4-week phase) and 12 hours (11 to 13 hours) postdose (second 4-week phase after treatment crossover). The primary outcome was the per-patient proportion (PPP; least squares means [95% confidence interval]) of affirmative responses to the Sexual Encounter Profile question 3 (SEP3: "Did your erection last long enough for you to have successful intercourse?").

RESULTS

For sildenafil (n = 174) versus placebo (n = 177), baseline values were similar but the PPP of successful intercourse attempts increased to 76% (69% to 82%) versus 50% (43% to 57%) in phase 1 (odds ratio [OR] = 3.2) and 79% (72% to 85%) versus 52% (44% to 60%) in phase 2 (OR = 3.5), and the PPP of Erection Hardness Score 4 erections (completely hard and fully rigid) was 41% (34% to 48%) versus 10% (7% to 15%) in phase 1 (OR = 6.2) and 44% (37% to 51%) versus 17% (12% to 23%) in phase 2 (OR = 4.0). Thus, at 12 hours, the odds of successful intercourse tripled and of a completely hard erection quadrupled. The sildenafil group achieved greater (P <0.001) PPP of successful penetration (SEP2), satisfaction with erection hardness (SEP4), and satisfaction with the sexual experience (SEP5); improvement in IIEF domain scores; and treatment satisfaction on the Erectile Dysfunction Inventory of Treatment Satisfaction.

CONCLUSIONS

In men with mild to moderate ED, responsiveness to sildenafil may persist much longer than 4 hours.