Comparative Effectiveness and Safety of Oral Phosphodiesterase Type 5 Inhibitors for Erectile Dysfunction: A Systematic Review and Network Meta-analysis

Continuation and effectiveness of tadalafil once daily during a 6-month observational study in erectile dysfunction: the EDATE study

AIMS

This was the first observational study evaluating treatment continuation, effectiveness and tolerability of tadalafil 5 mg once daily (TAD-OaD) in patients who chose and paid for treatment of erectile dysfunction (ED) in routine clinical practice.

METHODS

Men ≥ 18 years with ED, treated previously with phosphodiesterase type 5 (PDE5)-inhibitor on-demand (PRN) or treatment-naïve, were enrolled at 59 sites. For patients prescribed TAD-OaD at baseline (T1), change in erectile function (IIEF-EF and GAQ) was documented after 1-3 (T2) and 4-6 (T3) months. The primary outcome was the probability to switch/discontinue from TAD-OaD, estimated by Kaplan-Meier (KM) product-limit method. Changes in IIEF-EF were evaluated using a mixed model for repeated measures adjusting for patient baseline characteristics.

RESULTS

Of 975 men enrolled (median age 56.8 years, 33.7% with previous PDE5-inhibitor use), 778 were prescribed TAD-OaD, 135 TAD-PRN and 62 sildenafil or vardenafil PRN. During the 6-month longitudinal observation, 107 patients (13.8% of 778) switched or discontinued TAD-OaD-treatment. KM-rates (95%CI) for continuing TAD-OaD at 2, 4 and 6 months were 94.0% (92.3, 95.7), 88.3% (85.9, 90.6) and 86.3% (83.7, 88.9), respectively. The 25th percentile of time to switch/discontinuation of TAD-OaD was estimated as 31.1 weeks (lower 95%CI 30.3 weeks). At T3, IIEF-EF scores had increased by 7.1 (LSmean; 95%CI 5.8, 8.5) points; 91.3% of patients reported improved erections. The most frequently reported AE was headache (10 patients; 1.3%); no new/unexpected safety signals were observed.

CONCLUSION

Under routine conditions, and when patients were involved in treatment decision-making, more than 86% of men starting/switching to tadalafil once daily (OaD) at baseline continued tadalafil OaD treatment for ≥ 6 months.

Avanafil for erectile dysfunction in elderly and younger adults: differential pharmacology and clinical utility

The treatment modalities of erectile dysfunction range from oral pharmacotherapy to intracavernosal injections, intraurethral pellets, vacuum erectile devices, and the surgical option of penile prosthesis insertion. Oral phosphodiesterase 5 inhibitors still remain the preferred treatment for patients since they are the least invasive, not to mention that they can be prescribed by non-urologists. Due to these factors, there has been development of newer drugs with fewer side effects. This is a review of the second generation phosphodiesterase 5 inhibitor, avanafil, looking into its pharmacology as well as its clinical utility. Avanafil’s faster onset and shorter duration of action has made it preferred as compared to other PDE5 inhibitors for patients with multiple comorbidities.

The effectiveness and safety of avanafil for erectile dysfunction: a systematic review and meta-analysis

OBJECTIVE

To compare the efficacy and safety between different dosages of avanafil for the treatment of erectile dysfunction (ED).

METHODS

PubMed, Cochrane Library, and Embase were searched to identify randomized controlled trials which compared avanafil with placebo, or compared different dosages of avanafil for ED. International Index of Erectile Function-Erectile Function domain score (IIEF-EF), Sexual Encounter Profile Question (SEP) questions 2 and 3, and adverse events were considered as the study outcomes. Both pairwise meta-analysis and network meta-analysis were carried out.

RESULTS

Five studies including 2225 patients were assessed. The pairwise meta-analysis suggested that avanafil was more effective than placebo in improving IIEF-EF (mean difference [MD]: 4.47; 95% confidence interval [CI]: 3.51 to 5.43), SEP-2 (MD: 17.41; 95% CI: 14.03 to 20.79), and SEP-3 (MD: 20.01; 95% CI: 22.98 to 37.22), with an evident dose-response relationship. The effectiveness was significantly different between the 50 mg and 100 mg groups, or between the 50 mg and 200 mg groups, for all outcomes. Overall, avanafil was associated with a significantly higher incidence of any adverse event (risk ratio [RR]: 2.56; 95% CI: 1.66 to 3.94), serious adverse event (RR: 2.78; 95% CI: 1.34 to 5.76), flushing (RR: 6.06; 95% CI: 3.37 to 10.88) and headache (RR: 7.54; 95% CI: 3.52 to 16.12) when compared with placebo. No significant difference in safety was found among various dosage groups.

CONCLUSIONS

Avanafil, from 50 to 200 mg, is effective and well tolerated for the treatment of ED, and an increase in dosage is associated with a significant rise in effectiveness but not with significantly more adverse events.

Phosphodiesterase type 5 inhibitors for the treatment of post-nerve sparing radical prostatectomy erectile dysfunction in men

Prostate cancer (PCa) is the most common solid neoplasm diagnosed in developed countries. Nerve-sparing radical prostatectomy (NS-RP) has been widely accepted as the best choice treatment for localised PCa. However, erectile dysfunction (ED) and urinary incontinence are commonly observed after NS-RP. Using meta-analysis, we examined if phosphodiesterase type 5 inhibitors (PDE5-Is) could improve the symptoms of ED in patients undergoing NS-RP. This review contained seven randomised placebo-controlled trials with a total of 2,655 male patients. Patients in PDE5-Is group showed significant improvement in the International Index of Erectile Function-Erectile Function domain score (IIEF-EF), Global Assessment Questionnaire (GAQ), Sexual Encounter Profile question 2 (SEP-2) and SEP-3. Although the incidence of treatment-emergent adverse events (TEAEs) were high in both groups (56.44% vs. 40.63%), the safety profile were acceptable, with low incidence of discontinuation rate due to adverse events. Therefore, PDE5-Is are recommended for the treatment of post-NS-RP ED. Patients should be informed of possible adverse events.

Randomized controlled trial of sildenafil for preventing recurrent ischemic priapism in sickle cell disease

BACKGROUND

Successful preventive therapy for ischemic priapism, a disorder of penile erection with major physical and psychologic consequences, is limited. We conducted a randomized, double-blind, placebo-controlled clinical trial to assess the efficacy and safety of sildenafil by a systematic dosing protocol to prevent recurrent ischemic priapism associated with sickle cell disease.

METHODS

Thirteen patients with sickle cell disease reporting priapism recurrences at least twice weekly were randomized to receive sildenafil 50 mg or placebo daily, unassociated with sleep or sexual activity, for 8 weeks, followed by open-label use of this sildenafil regimen for an additional 8 weeks.

RESULTS

Priapism frequency reduction by 50% did not differ between sildenafil and placebo groups by intention-to-treat or per protocol analyses (P = 1.0). However, during open-label assessment, 5 of 8 patients (62.5%) by intention-to-treat analysis and 2 of 3 patients (66.7%) by per protocol analysis met this primary efficacy outcome. No significant differences were found between study groups in rates of adverse effects, although major priapism episodes were decreased 4-fold in patients monitored "on-treatment."

CONCLUSIONS

Sildenafil use by systematic dosing may offer a strategy to prevent recurrent ischemic priapism in patients with sickle cell disease.

American Cancer Society prostate cancer survivorship care guidelines

Prostate cancer survivors approach 2.8 million in number and represent 1 in 5 of all cancer survivors in the United States. While guidelines exist for timely treatment and surveillance for recurrent disease, there is limited availability of guidelines that facilitate the provision of posttreatment clinical follow-up care to address the myriad of long-term and late effects that survivors may face. Based on recommendations set forth by a National Cancer Survivorship Resource Center expert panel, the American Cancer Society developed clinical follow-up care guidelines to facilitate the provision of posttreatment care by primary care clinicians. These guidelines were developed using a combined approach of evidence synthesis and expert consensus. Existing guidelines for health promotion, surveillance, and screening for second primary cancers were referenced when available. To promote comprehensive follow-up care and optimal health and quality of life for the posttreatment survivor, the guidelines address health promotion, surveillance for prostate cancer recurrence, screening for second primary cancers, long-term and late effects assessment and management, psychosocial issues, and care coordination among the oncology team, primary care clinicians, and nononcology specialists. A key challenge to the development of these guidelines was the limited availability of published evidence for management of prostate cancer survivors after treatment. Much of the evidence relies on studies with small sample sizes and retrospective analyses of facility-specific and population databases.

Udenafil for the treatment of erectile dysfunction

Erectile dysfunction (ED) is often perceived by both patients and sexual partners as a serious problem that can jeopardize quality of life, psychosocial or emotional well-being, and the partnership in the long term. Since their introduction, oral phosphodiesterase type 5 inhibitors (PDE5Is) have been found to be highly effective and well tolerated, and are available as the first-line therapy for the treatment of ED. Udenafil is one of the selective PDE5Is made available in recent years for the treatment of ED. Udenafil has clinical properties of both relatively rapid onset and long duration of action due to its pharmacokinetic profile, thereby providing an additional treatment option for ED men to better suit individual needs. There is positive evidence that udenafil is effective and well tolerated in the treatment of ED of a broad spectrum of etiologies or severity. Udenafil is as effective in the treatment of diabetes mellitus-associated ED as other PDE5Is. Due to the clinical property of relatively long duration of action, udenafil may be another option in daily dosing treatment for ED, as suggested by its favorable efficacy and safety profile. Most adverse effects reported from clinical trials are mild or moderate in severity, without any serious adverse event, with headache and flushing being the most common. Also, the concomitant use of anti-hypertensive drugs or alpha-1-blockers does not significantly affect the efficacy and safety profile of udenafil. However, additional studies with larger cohorts including prospective, multicenter, comparative studies with patients of different ethnicities are needed to further validate the favorable findings of udenafil in the treatment of ED.

Mirodenafil for the treatment of erectile dysfunction: a systematic review of the literature

Phosphodiesterase type 5 (PDE5) inhibitors are the most commonly used treatment for erectile dysfunction (ED). Since the launch of sildenafil, several drugs-including mirodenafil, sildenafil citrate (sildenafil), tadalafil, vardenafil HCL (vardenafil), udenafil, and avanafil-have become available. Mirodenafil is a newly developed pyrrolopyrimidinone compound, which is a potent, reversible, and selective oral PDE5 inhibitor. Mirodenafil was launched in Korea in 2007, and an orally disintegrating film of mirodenafil was developed in 2011 for benefitting patients having difficulty in swallowing tablets. This study aimed to review the pharmacokinetic characteristic profile of mirodenafil and report evidence on its efficacy in the case of ED. In addition, we reviewed randomized controlled studies of mirodenafil's daily administration and efficacy for lower urinary tract symptoms.

The Efficacy and Safety of Tadalafil 5 mg Once Daily in the Treatment of Erectile Dysfunction After Robot-Assisted Laparoscopic Radical Prostatectomy: 1-Year Follow-up

PURPOSE

To evaluate the efficacy and safety of tadalafil 5 mg once daily use in the treatment of erectile dysfunction (ED) after robot-assisted laparoscopic radical prostatectomy (RALP).

MATERIALS AND METHODS

The study retrospectively evaluated 92 patients who underwent RALP at Dong-A University Hospital. The patients were surveyed by use of the abridged five-item version of the International Index of Erectile Function (IIEF-5) questionnaire, which was self-administered before surgery and at 6 months and 1 year after surgery. The 92 patients were classified into the tadalafil group (n=47) and the non-tadalafil group (n=45). Each group was then classified depending on the nerve-sparing (NS) procedure used: bilateral NS or unilateral NS.

RESULTS

At 6 months, the total IIEF-5 scores of the tadalafil group and the non-tadalafil group were 10.0±3.4 and 7.0±4.0, respectively. At 1 year, the total IIEF-5 score in the tadalafil group was significantly greater than that in the non-tadalafil group (13.2±5.6 vs. 7.7±4.8, p<0.0001). Statistically significant improvements (p<0.05) were observed in the tadalafil group for all 5 domains of the IIEF-5 score, whereas in the non-tadalafil group there was no significant improvement in any of the domains at 1 year. The reported side effects were flushing (8.5%, n=4), headache (4.3%, n=2), and dizziness (2.1%, n=1).

CONCLUSIONS

In ED patients after NS RALP, a once-daily dose of tadalafil 5 mg was well tolerated and significantly improved EF compared with that in the non-tadalafil group.

Phosphodiesterase type 5 inhibitors as a treatment for erectile dysfunction: Current information and new horizons

INTRODUCTION

Over the past 15 years, the discovery and development of oral medications that selectively inhibit the enzyme phosphodiesterase type 5 (PDE5) have revolutionised the treatment of erectile dysfunction (ED). Currently, three PDE5 inhibitors are widely available clinically, i.e., sildenafil, vardenafil and tadalafil. New PDE5 inhibitors, including avanafil and udenafil, are now in clinical use in a few countries, and other compounds are under development.

METHODS

We describe the current use and future direction of PDE5 inhibitors in the treatment of ED.

RESULTS AND CONCLUSION

Each PDE5 inhibitor has an excellent and comparable efficacy and tolerability. These drugs are highly effective for ED of various causes, and are effective in preventing ED after radical prostatectomy. However, whilst being at least 60% effective, PDE5 inhibitors are still ineffective in at least 30% of patients, prompting current research into other pharmacological targets for ED.