Phosphodiesterase type 5 (PDE5) inhibitors are used most commonly in the treatment of penile erectile dysfunction (ED). Recent studies show that PDE5 inhibitors are ideal drugs for treating ischemia-reperfusion injury. This review focuses on the results of basic and clinical researches on PDE5 inhibitors for the treatment of ischemia-reperfusion injury and provides some theoretical evidence for clinical options of the drugs.
Erectile Dysfunction ; drug therapy ; Humans ; Male ; Phosphodiesterase 5 Inhibitors ; therapeutic use ; Phosphodiesterase Inhibitors ; therapeutic use ; Reperfusion Injury ; drug therapy

Erectile dysfunction (ED) is a common problem, for which PDE5 inhibitors (PDE5I) represent the first line therapy at present and have a success rate of approximately 80%. Refractory ED, which refers to ED in some patients with chronic diseases such as diabetes mellitus and cardiovascular diseases or in those treated by radical prostatectomy, receives little benefit from PDE5I alone. Apart from the NO-cGMP pathway, the processes of erection and ED involve several signaling pathways, such as RhoA/Rho kinase, H2S, CO, etc. The complicated signaling network contributes to the pathogenesis of refractory ED. PDE5I-based alternative therapy and combined therapy may increase the success rate of its treatment. This article outlines the advances in the studies of refractory ED that fails to respond to PDE5I.
Erectile Dysfunction ; drug therapy ; Humans ; Male ; Phosphodiesterase 5 Inhibitors ; therapeutic use

OBJECTIVETo evaluate the clinical efficacy and safety of phosphodiesterase 5 (PDE-5) inhibitors for erectile dysfunction (ED) in patients with diabetes mellitus and provide some evidence for the clinical treatment of the disease.

METHODSWe searched MedMed, EMbase, Cochrane Library, CNKI, Wan Fang Data, VIP and ZADL for randomized controlled trials on PDE-5 inhibitors for ED in diabetic men and evaluated the methodology of the included trials with the Jadad scale. We used the erectile function domain in the IIEF (IIEF-EF), IIEF questions (IIEF-Q) 3 and 4, SEP-2 and -3, and Global Assessment Questions (GAQ) as the main evaluation indexes and employed the Review Manager 5. 1. 0 software for meta analysis.

RESULTSA total of 13 studies were included, which were all high quality trials with Jadad score > 3. The IIEF-EF scores in 10 of the included studies were subjected to meta analysis using the random-effect model (REM), with a weighted mean difference (WMD) of 5.64 (95% CI 4.41 - 6.83, P < 0.001). The fixed-effect model (FEM) analysis of the IIEF-Q scores in 6 of the studies showed the WMD to be 0.96 (95% CI 0.83 -1.08, P < 0.001) for IIEF-Q3 and 1.11 (95% CI 0.98 - 1.25, P < 0.001) for IIEF-Q4. FEM analysis of the SEP-2 scores showed WMD = 17.67 (95% CI 12. 38 - 22. 97, P < 0.001) in 2 of the studies, and that of the SEP-3 scores WMD = 23.64 (95% CI 17. 49 - 29.79, P < 0.001) in 5 of the studies. The GAQ scores in 11 of the studies were subjected to REM analysis, with OR = 6. 20 and 95% CI 3.65 - 10.52 (P < 0.001). REM analysis was performed on the adverse reactions in 11 of the studies, with OR = 7.43 and 95% CI 4.11 - 13.44 (P < 0.001).

CONCLUSIONPDE-5 inhibitors can effectively and safely improve erectile function in patients with diabetes mellitus.

Diabetes Mellitus ; Erectile Dysfunction ; drug therapy ; Gangliosides ; Humans ; Male ; Penile Erection ; Phosphodiesterase 5 Inhibitors ; therapeutic use

BACKGROUNDErectile dysfunction (ED) is a common impairment among older men, and the prevalence rates increase sharply after age of 60 years. Most studies have focused on the prevalence rate or dangerous factors. The aim of this study was to investigate the basic epidemiologic data about ED patients with different ED courses. The purpose of this research was to understand the therapeutic effect of phosphodiesterase type 5 inhibitor (PDE5-I) and see how and why the ED course impact the progress of ED and the therapeutic effect of PDE5-I treatment.

METHODSFrom June 2008 to June 2009, 4252 questionnaires (Quality of Erection Questionnaire, QEQ) were gathered from 46 centers by urology or andrology doctors all around China. Patients with ED (age ≥ 20 years) filled in first half of the questionnaires when they came for the first time, and then completed the second half 4 weeks after PDE5-I therapy.

RESULTSED courses of most patients were less than 5 years (< 5 years, 74.0%; 5 - 10 years 20.8%; > 10 years, 5.2%). As ED course increasing, the incidence of the risk factors of ED, such as smoking, drinking, hypertension, diabetes, heart disease and hyperlipidemia also increase (P ≤ 0.01). PDE5-I was effective in improving the quality of sexual activities (P ≤ 0.01). Administration of PDE5-I improves satisfaction, enjoyment and frequency of sexual activities. The longer the ED course, the worse the therapeutic effect (< 5 years, 96.1%; 5 - 10 years, 94.9%; > 10 years, 89.0%) (P ≤ 0.01).

CONCLUSIONSThe ED course greatly affected the therapeutic effect of PDE5-1, the patients with ED should consult doctor at early stage of the disease. Administration of PDE5-I effectively improves the penile erection and the quality of sexual life of the patients hence should be considered as first-line medicine in the treatment of ED.

Adult ; Erectile Dysfunction ; drug therapy ; epidemiology ; physiopathology ; Humans ; Male ; Phosphodiesterase 5 Inhibitors ; therapeutic use ; Surveys and Questionnaires

Erectile dysfunction (ED) is a common disorder that affects the quality of life of both men and their partners. The phosphodiesterase type 5 inhibitor is the first-line drug for ED. Recent researches found that long-term administration of low-dose phosphodiesterase type 5 inhibitors to be a safe and effective therapy for ED, as well as for couples who may prefer more convenience and spontaneity in their sexual activities. Besides, it provides a new therapeutic option for refractory ED. Its action mechanism mainly involves the improvement of the endothelial function of penile vessels and/or maintenance of the function and number of smooth muscle cells. However, whether this therapy can maintain the improved erection function after drug withdrawal needs further studies.
Erectile Dysfunction ; drug therapy ; Humans ; Male ; Phosphodiesterase 5 Inhibitors ; administration & dosage ; therapeutic use ; Treatment Outcome

Medication has become the first-line option for the management of lower urinary tract symptoms induced by benign prostatic hyperplasia (LUTS/BPH) for its advantages in controlling the symptoms, inhibiting BPH progression, and reducing serious complications and surgical risks. Recent years have witnessed remarkable achievement in the studies of phosphodiesterase type 5 inhibitors (PDE5-Is) in the treatment of LUTS/BPH. PDE5-Is can effectively alleviate LUTS/BPH, with even better efficacy when combined with al-ARAs.
Humans ; Lower Urinary Tract Symptoms ; drug therapy ; etiology ; Male ; Phosphodiesterase 5 Inhibitors ; therapeutic use ; Prostatic Hyperplasia ; complications

The majority of men with spinal cord injury (SCI) suffer from different types and degrees of erectile dysfunction (ED). The impact of SCL on erectile function depends on the severity and location of the injury. Some patients can restore the residual sexual potential in the period of SCI recovery. Treatments of ED in men with SCI include psychotherapy, medication of oral PDE5 inhibitors, intracavernous injection of vasoactive drugs, transurethral medication, application of the vacuum erectile device and penile ring, penile prostheses, sacral neuromodulation, etc., among which PDE5 inhibitors remain the first option and usually give good clinical results for those with higher SCI. However, intracavernous injection of vasoactive drugs and combined treatment are preferable for those with lower SCI.
Erectile Dysfunction ; etiology ; therapy ; Humans ; Male ; Penile Prosthesis ; Phosphodiesterase 5 Inhibitors ; therapeutic use ; Psychotherapy ; Spinal Cord Injuries ; complications

OBJECTIVETo evaluate phosphodiesterase type 5 (PDE5) inhibitors in the management of temporary penile erectile dysfunction (ED) in patients undergoing assisted reproductive technology (ART).

METHODSThis study included 75 male patients that experienced ejaculation failure due to temporary ED during ART treatment. We treated the patients with PDE5 inhibitors sildenafil, tadanafil and vardenafil, and then evaluated the hardness of penile erection using Erection Hardness Score (EHS) and analyzed the end-point efficacy.

RESULTSSildenafil was administered to 28 of the patients, tadanafil to 25, and vardenafil to 22. Of the total number of patients, 61 (81.3%) achieved effective erection, but no significant differences were observed in the rate of effectiveness among the sildenafil (24 cases, 85.7%), tadanafil (20 cases, 80.0%) and vardenafil (17 cases, 77.3%) groups (P > 0.05). After medication, 53 (70.7%) of the patients successfully ejaculated, but there were no remarkable differences in the success rate among the sildenafil (21 cases, 75.0%), tadanafil (17 cases, 68.0%) and vardenafil (15 cases, 68.2%) groups (P > 0.05). Of the 75 patients, 37 received the recommended initial dose and 38 the maximum recommended dose of PDE5 inhibitors, but no significant differences were found in the rate of successful sperm retrieval between the former (28 cases, 75.7%) and the latter group (25 cases, 65.8%) (P > 0.05). Mild adverse events, including transient flush and dizziness, occurred in 5 cases (6.7%).

CONCLUSIONPDE5 inhibitors can help temporary ED patients to achieve penile erection and ejaculation during ART treatment.

Ejaculation ; Erectile Dysfunction ; drug therapy ; Humans ; Imidazoles ; therapeutic use ; Male ; Phosphodiesterase 5 Inhibitors ; therapeutic use ; Piperazines ; therapeutic use ; Purines ; therapeutic use ; Reproductive Techniques, Assisted ; Sildenafil Citrate ; Sulfonamides ; therapeutic use ; Sulfones ; therapeutic use ; Triazines ; therapeutic use ; Vardenafil Dihydrochloride

In recent years, more and more attention has been drawn to the role of phosphodiesterase 5 (PDE5) in penile erection. The cyclic nucleotide (cGMP) signaling pathway mediates the smooth-muscle relaxing effect of nitric oxide necessary for normal erectile function. Down-regulation of this pathway is the pathological pivot of many forms of erectile dysfunction (ED) and leads to the development of some chronic diseases. Therapeutic outcomes have shown that vardenafil is effective and safe in the treatment of ED associated with dyslipidemia, hypertension, depression, diabetes, radical retropubic prostatectomy, spinal cord injury, sildenafil failure, renal transplantation, chronic prostatitis and that accompanied by premature ejaculation. Vardenafil provides a reasonable therapeutic alternative for these refractory ED patients. In addition, vardenafil can prolong erectile duration of ED patients.
Cyclic Nucleotide Phosphodiesterases, Type 5 ; therapeutic use ; Erectile Dysfunction ; drug therapy ; Humans ; Imidazoles ; therapeutic use ; Male ; Phosphodiesterase Inhibitors ; therapeutic use ; Piperazines ; therapeutic use ; Sulfones ; therapeutic use ; Triazines ; therapeutic use ; Vardenafil Dihydrochloride ; Vasodilator Agents ; therapeutic use

The enzyme phosphodiesterase-5 (PDE-5), widely distributed in the heart, smooth muscle, and blood vessels, catalyzes the hydrolysis of cyclic guanosine monophosphate (cGMP), a potent vasodilator, and is also a nitric oxide (NO) donor. Tadalafil is the first PDE 5 inhibitor approved by FDA for the treatment of ED. Recent studies have shown several pleiotropic beneficial effects of PDE-5 inhibitors in patients with cardiovascular diseases (coronary heart disease, hypertension, heart failure, and pulmonary arterial hypertension) and diabetes mellitus. It has been demonstrated that tadalafil can not only improve sexual function, but also elevate the endothelial cell-derived NO level, activate protein kinase A, upregulate the intracellular Ca2+ concentration, and improve hemodynamic indexes. Thus, the PDE-5 inhibitor tadalafil, with its cardiovascular-protective effect, can be a therapeutic option for the treatment of ED patients with cardiovascular disease.
Carbolines ; pharmacology ; therapeutic use ; Cardiovascular Diseases ; complications ; drug therapy ; Erectile Dysfunction ; complications ; drug therapy ; Humans ; Male ; Phosphodiesterase 5 Inhibitors ; pharmacology ; therapeutic use ; Tadalafil