Erectile dysfunction: on the efficacy of a phosphodiesterase inhibitor in patients with multiple risk factors

1 Introduction With the 1998 introduction of sildenafil (Viagra), the first available oral phosphodiesterase inhibitor, there

Erectile dysfunction: on the efficacy of a phosphodiesterase inhibitor with concurrent sex therapy

1 Introduction Erectile dysfunction (ED) is a condition that affects perhaps 25 to 30 million men in the U.S.A. constituting

Effect of phosphodiesterase inhibitors in the bladder

Many aging men will experience lower urinary tract symptoms(LUTS).Phosphodiesterase type 5(PDE5)inhibitors have shown promise in treating LUTS in these patients.PDE5 inhibitors mediate their effects through several pathways including cAMP,NO/cGMP,Kchannel modulated pathways,and the L-cysteine/H2S pathway.PDE5 inhibitors exert their effect in muscle cells,nerve fibers,and interstitial cells(ICs).The use of PDE5 inhibitors led to improvement in LUTS.This included urodynamic parameters.PDE5 inhibitors may play a significant role in LUTS due to their effect on the bladder rather than the prostate.

Effects of phosphodiesterase 5 inhibitors on sperm parameters and fertilizing capacity

The aim of this review study is to elucidate the effects that phosphodiesterase 5 （PDE5） inhibitors exert on spermatozoa motility, capacitation process and on their ability to fertilize the oocyte. Second messenger systems such as the cAMP/adenylate cyclase （AC） system and the cGMP/guanylate cyclase （GC） system appear to regulate sperm functions. Increased levels of intracytosolic cAMP result in an enhancement of sperm motility and viability. The stimulation of GC by low doses of nitric oxide （NO） leads to an improvement or maintenance of sperm motility, whereas higher concentrations have an adverse effect on sperm parameters. Several in vivo and in vitro studies have been carried out in order to examine whether PDE5 inhibitors affect positively or negatively sperm parameters and sperm fertilizing capacity. The results of these studies are controversial. Some of these studies demonstrate no significant effects of PDE5 inhibitors on the motility, viability, and morphology of spermatozoa collected from men that have been treated with PDE5 inhibitors. On the other hand, several studies demonstrate a positive effect of PDE5 inhibitors on sperm motility both in vivo and in vitro. In vitro studies of sildenafil citrate demonstrate a stimulatory effect on sperm motility with an increase in intracellular cAMP suggesting an inhibitory action of sildenafil citrate on a PDE isoform other than the PDE5. On the other hand, tadalafil＇s actions appear to be associated with the inhibitory effect of this compound on PDE11. In vivo studies in men treated with vardenafil in a daily basis demonstrated a significantly larger total number of spermatozoa per ejaculate, quantitative sperm motility, and qualitative sperm motility; it has been suggested that vardenafil administration enhances the secretory function of the prostate and subsequently increases the qualitative and quantitative motility of spermatozoa. The effect that PDE5 inhibitors exert on sperm parameters may lead to the improvement of the outcome of assisted reproductive technology （ART） programs. In the future PDE5 inhibitors might serve as adjunct therapeutical agents for the alleviation of male infertility.

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〈O.O001）. 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 beine diaenosed with orostate cancer. Further research is warranted.

Erectile potentials of a new phosphodiesterase type 5 inhibitor, DA-8159, in diet-induced obese rats

Aim： To examine the changes in the erectile function in diet-induced obese rats and investigate the oral efficacy of DA-8159, a new phosphodiesterase type 5 （PDE5） inhibitor, on penile erection in obese rats. Methods： The rats were fed a high-energy diet for 12 weeks and divided into three groups： an obesity-resistant （OR） control group, an obesity-prone （OP） control group, and an OP-DA-8159 treatment （DA-8159） group. The electrostimulation-induced erectile responses were measured in all groups. The body weight, plasma cholesterol, triglyceride and glucose levels were also measured. Results： In the OP control group, the maximum intracavernous pressure （ICP） and ICP/blood pressure （ICP/BP） ratio after electric stimulation were significantly lower than those in OR control group. The corresponding area under the curve （AUC） of the ICP/BP ratio, the detumescence time and the baseline cavernous pressure were also lower than those in the OR control group, but this difference was not significant. The body weight gain, plasma cholesterol and triglyceride level in the OP group were significantly higher than those in the OR group. After administering the DA-8159, a significant increase in the maximum ICP and the ICP/BP ratio were observed. The corresponding AUCs in the DA-8159 group were also higher than those in the two control groups. Furthermore, the detumescence time was significantly prolonged after treatment with DA-8159. Conclusion： These results demon- strate that diet-induced obesity affects the erectile function in rats and these erectile dysfunction （ED） can be improved by the treatment with DA-8159, indicating DA-8159 might be a treatment option for ED associated with obesity.

The use of antimuscarinics,phosphodiesterase type Ⅴ inhibitors and phytotherapy for lower urinary tract symptoms in men

Besides the mainstay of α-blockers and 5α-reductase inhibitors,other forms of medical therapy complete the armamentarium in the treatment of lower urinary tract symptoms(LUTS)in men.These treatments can target specific symptoms as well as associated symptoms that would affect the quality of life of the patients.Many patients are bothered by storage symptoms,more so than the voiding symptoms.Antimuscarinics are efficacious and safe,provided the patients do not have high post void residual urine.Many patients with LUTS also have erectile dysfunction,and phosphodiesterase type Ⅴ inhibitors are effective in relieving both LUTS as well as erectile dysfunction for such patients.Phytotherapy provides a popular and safe treatment for LUTS,however,the efficacy of the treatment has not been proven in well conducted prospective randomized controlled studies.

Evaluation and diagnostic testing of erectile dysfunction in the era of phosphodiesterase type 5 inhibitors

The diagnosis and treatment of erectile dysfunction has changed dramatically since the availability of safe and effective oral therapies. Unfortunately, not all men can be adequately treated in this way, and might require more invasive testing to diagnose and treat the specific cause of their dysfunction. This review looks at the tests and strategies available for men who cannot be treated by oral therapy alone.

Statin, testosterone and phosphodiesterase 5-inhibitor treatments and age related mortality in diabetes

AIMTo determine how statins, testosterone (T) replacement therapy (TRT) and phosphodiesterase 5-inhibitors (PDE5I) influence age related mortality in diabetic men.METHODSWe studied 857 diabetic men screened for the BLAST study, stratifying them (mean follow-up = 3.8 years) into: (1) Normal T levels/untreated (total T > 12 nmol/L and free T > 0.25 nmol/L), Low T/untreated and Low T/treated; (2) PDE5I/untreated and PDE5I/treated; and (3) statin/untreated and statin/treated groups. The relationship between age and mortality, alone and with T/TRT, statin and PDE5I treatment was studied using logistic regression. Mortality probability and 95%CI were calculated from the above models for each individual.RESULTSAge was associated with mortality (logistic regression, OR = 1.10, 95%CI: 1.08-1.13, P < 0.001). With all factors included, age (OR = 1.08, 95%CI: 1.06-1.11, P < 0.001), Low T/treated (OR = 0.38, 95%CI: 0.15-0.92, P = 0.033), PDE5I/treated (OR = 0.17, 95%CI: 0.053-0.56, P = 0.004) and statin/treated (OR = 0.59, 95%CI: 0.36-0.97, P = 0.038) were associated with lower mortality. Age related mortality was as described by Gompertz, r2 = 0.881 when Ln (mortality) was plotted against age. The probability of mortality and 95%CI (from logistic regression) of individuals, treated/untreated with the drugs, alone and in combination was plotted against age. Overlap of 95%CI lines was evident with statins and TRT. No overlap was evident with PDE5I alone and with statins and TRT, this suggesting a change in the relationship between age and mortality.CONCLUSIONWe show that statins, PDE5I and TRT reduce mortality in diabetes. PDE5I, alone and with the other treatments significantly alter age related mortality in diabetic men.

EFFECTS OF NOVEL PHOSPHODIESTERASE 4 INHIBITORS,ARIFLO AND SB242126A, ON ENDOTHELIN-1-INDUCED CONTRACTILITY OF ISOLATED HUMAN MYOMETRIUM

Objective To investigate the effects of novel selective phosphodiesterase4 (PDE4) inhibitors,Ariflo and SB242126A, on the endothelin-1 (ET-1) - induced contractility occurring in nonpregnant human myome-trium specimens. Methods Contractile responses to Ariflo and SB242126A were recorded cumulatively on isola-ted human longitudinal myometrium specimens obtained through surgical operations. Results Ariflo andSB242126A could inhibit both the frequency and amplitude of spontaneous contractions of myometrium (pD2 =8. 6and 7. 6,n =4) and ET-1 -induced contractions in a concentration-dependent manner (pD2 = 7. 7 and 8. 1 ,n =5) ,with a potency similar to that of Rolipram. Conclusion Ariflo and SB242126A have an obvious inhibitory effecton endothelin-1-induced contractility of isolated human myometrium. The finding suggested that PDE4 inhibitorsmight have clinical potential in treating preterm labour and dysmenorrhoea.

Erectile potentials of a new phosphodiesterase type 5 inhibitor,DA-8159,in diet-induced obese rats

Aim:To examine the changes in the erectile function in diet-induced obese rats and investigate the oral efficacy of DA-8159,a new phosphodiesterase type 5(PDE5)inhibitor,on penile erection in obese rats.Methods:The rats were fed a high-energy diet for 12 weeks and divided into three groups:an obesity-resistant(OR)control group,an obesity- prone(OP)control group,and an OP-DA-8159 treatment(DA-8159)group.The electrostimulation-induced erectile responses were measured in all groups.The body weight,plasma cholesterol,triglyceride and glucose levels were also measured.Results:In the OP control group,the maximum intracavernous pressure(ICP)and ICP/blood pressure(ICP/BP)ratio after electric stimulation were significantly lower than those in OR control group.The corresponding area under the curve(AUC)of the ICP/BP ratio,the detumescence time and the baseline cavernous pressure were also lower than those in the OR control group,but this difference was not significant.The body weight gain,plasma cholesterol and triglyceride level in the OP group were significantly higher than those in the OR group. After administering the DA-8159,a significant increase in the maximum ICP and the ICP/BP ratio were observed.The coerrsponding AUCs in the DA-8159 group were also higher than those in the two control groups.Furthermore,the detumescence time was significantly prolonged after treatment with DA-8159.Conclusion:These results demon- strate that diet-induced obesity affects the erectile function in rats and these erectile dysfunction(ED)can be im- proved by the treatment with DA-8159,indicating DA-8159 might be a treatment option for ED associated with obesity.

Value of phosphodiesterase 5 inhibitors as a combination therapy for treating erectile dysfunction:A literature review

Erectile dysfunction(ED)is increasing in prevalence,with estimates that 50%of men between 40 and 70 years of age suffer from the disease.Due to a wide array of available medical interventions,significant focus has been put on combination therapies that can treat ED refractory to first-line treatments such as phosphodiesterase 5 inhibitors(PDE5is).However,reviews evaluating monotherapy noninferiority and patient satisfaction of monotherapy versus combination therapy are lacking.A thorough PubMed search was performed to evaluate combination therapy in ED treatment.Articles published between January 2008 and June 2023 were reviewed,including randomized control trials,retrospective analyses,and cohort studies.Combination therapies included PDE5i plus another PDE5i,testosterone supplementation,α-blockers,vacuum erectile devices,intracavernosal injections,and low-intensity shockwave therapy.Based on this review,PDE5i monotherapy is not inferior to combination therapy and has increased satisfaction,convenience,and ease of use for patients with ED.Limitations of current literature on combination therapy include small sample size,limited data on patient satisfaction,possible biases,and limited follow-up time.Further studies will need larger randomized control trials with follow-up times greater than 1 year.

Patterns of treatment with PDE5 inhibitors in the clinical practice in Italy： longitudinal data from the Erectile Dysfunction Observational Study

The Erectile Dysfunction Observational Study （EDOS） is a 6-months observational prospective multicentric study enrolling men with erectile dysfunction （ED） who asked, to be started on a treatment or to change a previous treatment. Aims of the study were to analyse the pattern of treatment and compare the efficacy of treatments used. Patients were enrolled during a normal hospital visit and were prescribed a treatment for ED. They were asked at baseline and after 3 and 6 months, to answer a set of questions from the International Index of Erectile Function, Erectile Dysfunction Inventory of Treatment Satisfaction （EDITS） and Short Form of the Psychological and Interpersonal Relationships Scale questionnaires （SF-PAIRS）. Clinicians were free to prescribe any therapy for ED available in the market, and to change therapy at any time during the study. Out of 1 338 patients, available for analysis at 6 months, 624 （47%） changed their treatment during the study and 714 （53%） continued with the drug prescribed at baseline. Patients assuming tadalafil had a significantly higher probability of maintaining the same treatment compared to sildenafil or vardenafil. There was no clinically significant difference in terms of efficacy, patient satisfaction, self-confidence and spontaneity between the different inhibitors of PDE5. The ‘time concerns＇ domain score of SF-PAIRS, was statistically better in patients assuming tadalafil. In conclusion sildenafil, vardenafil and tadalafil show similar efficacy in the clinical practice. However, patients receiving tadalafil display a lower risk to discontinue or change the treatment.

Prevalence and medical management of erectile ：lysfunction 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 mirodenafih 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.

New oral agents for erectile dysfunction: what is changing in our practice?

Erectile dysfunction (ED) is a highly prevalent disorder affecting an estimated 152 million men worldwide and isassociated with a variety of behavioral risk factors, such as cigarette smoking and excessive alcohol consumption, aswell as numerous age - related medical conditions, notably type-2 diabetes mellitus and cardiovascular disease. A ratio-nal step - wise approach which includes comprehensive medical and sexual history, a focused physical examination andessential laboratory tests such as fasting glucose, lipid profile and testosterone assay is to be preferred. Current diagnos-tic work - up does not recommend any of the specialized tests which were previously considered mandatory-i. e. penilepharmacotesting, Duplex ultrasound and nocturnal penile tumescence. Hormonal replacement therapy is appropriate onlyin the hypogonadal male with ED. Prior to direct intervention, the physician should consider altering modifiable riskfactors or causes, although frequently insufficient to reverse ED completely. When indicated, oral therapy with newmolecules (phosphodiesterase inhibitors or apomorphine) is the first - line treatment for the majority of patients becauseof potential benefits and lack of invasiveness. (Asian J Androl 2001 Sep; 3: 175-179 )

Efficacy and safety of tadalafil taken as needed for the treatment of erectile dysfunction in Asian men： results of an integrated analysis

We evaluated the efficacy and safety of as-needed tadalafil in a diverse clinical population （with varying patient demographics, disease severity, and comorbid medical conditions） of Asian men with erectile dysfunction （ED）. An integrated analysis of five double-blind, placebo-controlled trials （N = 1 046） was performed. Patients were randomly assigned to receive 10 mg tadalafil （N = 185）, 20 mg tadalafil （N = 510）, or placebo （N = 351）. Efficacy assessments included the International Index of Erectile Function （IIEF）, Sexual Encounter Profile （SEP） diary and Global Assessment Question （GAQ）. Patients receiving 10 mg or 20 mg tadalafil showed significant improvement from baseline-to-end point on the Erectile Function domain of the International Index of Erectile Function （IIEF-EF） domain score in all clinical sub-populations analyzed, compared with patients receiving placebo （P 〈 0.001）. The 10-mg and 20-mg tadalafil groups showed a mean success rate of 64.1% and 70.5% for sexual intercourse attempts （SEP3, successful intercourse）, respectively, compared with 33.4% in the placebo group （P 〈 0.001）, and 85.5% and 85.4% reported improved erections at end point GAQ, respectively, versus 43.5% in the placebo group （P 〈 0.001）. Tadalafil was well tolerated across all groups studied. Headache and back pain were the most frequently reported adverse events. Overall, tadalafil was effective and well tolerated across a diverse clinical spectrum of Asian men with ED.

Effects of phosphodiesterase 4 inhibitor on cough response in guinea pigs sensitized and challenged with ovalbumin

BACKGROUND: There is currently considerable interest in the potential value of selective inhibitors of cyclic nucleotide phosphodiesterase 4 in the treatment of asthma. However, whether they influence eosinophilic airway inflammation-associated cough remains unclear. The objective of this study was to investigate the effects of selective phosphodiesterase 4 inhibitor SB207499 on cough response and airway inflammation in guinea pigs sensitized and challenged with ovalbumin. METHODS: Forty sensitized guinea pigs were randomly divided into four groups: control (n = 10), challenge (n = 10), SB207499 (n = 10) and aminophylline (n = 10), then challenged with aerosol of 1% ovalbumin or saline. Two hours later, animals were intraperitoneally injected with either saline, 25 mg/kg of SB207499 or aminophylline. At the 24th hour, the injection was repeated with 2.5 mg/kg and 25 mg/kg SB207499 or aminophylline, then cough response to inhaled capsaicin and airway responsiveness to methacholine inducing a 150% of the peak airway pressure to the baseline (PC150) was measured. Finally, total cell number and differentials in bronchoalveolar lavage fluid were analysed. RESULTS: The cough frequency per 3 minutes and PC150 in the challenge group were (22 +/- 4) times/3 minutes and (198 +/- 54) microg/ml, which were significantly different from (6 +/- 2) times/3 minutes and (691 +/- 81) microg/ml in the control group (P

Efficacy and tolerability of vardenafil in Asian men with erectile dysfunction

Aim： To evaluate the efficacy and tolerability of vardenafil, a phosphodiesterase type-5 （PDE-5） inhibitor, in men of Asian ethnicity with erectile dysfunction （ED）. Methods： In this prospective, double-blind, multinational study, Asian men were randomized to receive vardenafil （10 mg） or placebo （4：1 ratio） for 12 weeks. The primary efficacy variables were the International Index of Erectile Function erectile function domain （IIEF-EF）, and Sexual Encounter Profile （SEP） questions related to penetration and intercourse completion. Significant mean improvements were required in all three measures to show positive benefits of vardenafil treatment. Secondary efficacy variables included the Global Assessment Question （GAQ） on erection improvement. Results： Least-squares mean baseline IIEF-EF domain scores （vardenafil 14.6, placebo 13.4） were consistent with moderate ED. After 12 weeks, vardenafil treatment was associated with significant increases from the baseline in IIEF-EF domain scores compared with the placebo （22.4 vs. 14.3; P 〈 0.001）. Vardenafil was associated with significant improvements from baseline in least squares （LS） mean success rates for SEP-2 （vardenafil 82.2 vs. placebo 43.6; P 〈 0.001） and SEP-3 （vardenafil 66.1 vs. placebo 24.0; P 〈 0.001）. Positive GAQ responses were reported by 81.8% of vardenafil recipients vs. 24.3% of placebo recipients. Adverse events were reported by 25.4% of the vardenafil group, the majority mild and transient. Conclusion： Vardenafil （10 mg） is a highly effective and well-tolerated treatment for moderate ED in Asian men. These results add to the increasing amount of data demonstrating the safety and efficacy of vardenafil for the treatment of ED in a range of patient populations.

Effects of Ginkgo biloba extracts with mirodenafil on the relaxation of corpus cavernosal smooth muscle and the potassium channel activity of corporal smooth muscle cells

In this study, we investigated the effects of a combination of Ginkgo biloba extracts （GBE） and phosphodiesterase type 5 （PDE-5） inhibitors on the muscular tone of the corpus cavernosum and potassium channel activity of corporal smooth muscle cells. Strips of corpus cavernosum from male New Zealand white rabbits were mounted in organ baths for isometric tension studies. After contraction with 1 × 10^-5 mol I^-1 norepinephrine, GBE （0.01-1 mg ml^-1） and mirodenafil （0.01-100 nmol I^-1） were added together into the organ bath. In electrophysiological studies, whole-cell currents were recorded by the conventional patch-clamp technique in cultured smooth muscle cells of the human corpus cavernosum. The corpus cavemosum was relaxed in response to GBE in a dose-dependent manner （from 0.64%±8.35% at 0.01 mg ml^-1 to 52.28%±11.42% at 1 mg ml^-1）. After pre-treatment with 0.03 mg ml^-1 of GBE, the relaxant effects of mirodenafil were increased at all concentrations, After tetraethylammonium （TEA） （1 mmol I^-1） administration, the increased effects were inhibited （P〈0.01）. Extracellular administration of GBE increased the whole-cell K^＋ outward currents in a dose-dependent fashion. The increase of the outward current was inhibited by I mmol 1-1 TEA. These results suggest that GBE could increase the relaxant potency of mirodenafil even at a minimally effective dose. The K＋ flow through potassium channels might be one of the mechanisms involved in this synergistic relaxation.

Sexual dysfunctions and their treatment in liver diseases

Sexual dysfunction(SD)is a prevalent but very commonly ignored aspect in the treatment of liver diseases and cirrhosis.The etiology of SD is multifactorial and therefore treatment strategies are complex,especially in females.Phosphodiesterase inhibitors are useful and effective in erectile dysfunction in males but in females,no single drug is available for SD,therefore multimodal treatment is required depending upon the cause.The foremost and fundamental requirement in both genders is to be stress-free and have adequate control of liver diseases.Improved quality of life is helpful in improving SD and vice versa is also true.Therefore,patients suffering from liver diseases should come forward and ask for treatment for SD,and physicians should actively enquire about SD while history taking and evaluating these patients.SD results in deterioration of quality of life,and both are modifiable and treatable aspects of liver diseases,which are never addressed actively,due to social taboos and fears of SD treatment in the presence of liver diseases.The diagnosis of SD does not require costly investigations,as the diagnosis can be established based on validated questionnaires available for both genders,therefore detailed targeted history taking using questionnaires is essential.Data are emerging in this area but is still at an early stage.More studies should be dedicated to SD in liver diseases.