Oral and injectable medications for the treatment of erectile dysfunction

Prostaglandins as a Topical Therapy for Erectile Dysfunction: A Comprehensive Review

INTRODUCTION

Erectile dysfunction (ED) is a substantial cause of dissatisfaction among many men. This discontentment has led to the emergence of various drug treatment options for this problem.

OBJECTIVES

Unfortunately, due to various interactions, contraindications, and side effects, systemic therapies such as phosphodiesterase-5 inhibitors (including sildenafil, tadalafil, vardenafil, avanafil, etc.) are not welcomed in many patients. These problems have led researchers to look for other ways to reduce these complications.

METHODS

This article holistically reviews the efficacy of topical prostaglandins and their role in treating ED. We sought to provide a comprehensive overview of recent findings on the current topic by using the extensive literature search to identify the latest scientific reports on the topic.

RESULTS

In this regard, topical and transdermal treatments can be suitable alternatives. In diverse studies, prostaglandins, remarkably PGE1 (also known as alprostadil), have been suggested to be an acceptable candidate for topical treatment.

CONCLUSION

Numerous formulations of PGE1 have been used to treat patients so far. Still, in general, with the evolution of classical formulation methods toward modern techniques (such as using nanocarriers and skin permeability enhancers), the probability of treatment success also increases.

Relationship between nocturnal penile tumescence parameters, International Index of Erectile Function symptom scores and sildenafil responses

OBJECTIVE

To evaluate the correlation between International Index of Erectile Function (IIEF) questionnaire scores, nocturnal penile tumescence parameters and sildenafil response in patients with erectile dysfunction using a minimal investigations approach.

MATERIAL AND METHODS

A total of 97 patients without any risk factors for erectile dysfunction were included. After completing the IIEF questionnaire, nocturnal penile tumescence monitoring was performed in all patients for 1 or 2 nights. Subsequently, sildenafil was given at a dosage of 50 or 100 mg according to the response. The relationship between nocturnal penile tumescence results, the severity of erectile dysfunction according to the IIEF questionnaire and sildenafil response was evaluated using Pearson's chi2 test.

RESULTS

Based on the questionnaire scores, 25 patients (25.8%) had mild, 44 (45.4%) had moderate and 28 (28.8%) had severe erectile dysfunction. Forty-four patients (45.4%) had normal and 53 (54.6%) had abnormal parameters after nocturnal penile tumescence recording. The sildenafil response was positive in 63 patients (64.9%) who were given 50 mg and in 26 (26.8%) who were given 100 mg. However, eight patients (8.2%) did not respond to sildenafil. While the severity of erectile dysfunction according to IIEF scores and the sildenafil response did not show any correlations with nocturnal penile tumescence results, there was a statistically significant relationship between sildenafil response and the severity of erectile dysfunction.

CONCLUSION

Changing concepts in the evaluation of ED have resulted in the use of effective therapeutic applications consistent with the degree of symptoms of patients without the waste of time caused by performing expensive, invasive, ineffective and time-consuming diagnostic tests.

Specific aspects of erectile dysfunction in spinal cord injury

According to preliminary studies, the overall incidence of spinal cord injury (SCI; traumatic and medical) in Spain is estimated to be between 12 and 20 per million inhabitants, and almost 80% of these injuries occur in young men. SCI causes organic changes in men leading to erectile dysfunction (ED), impaired ejaculation, and changes in genital orgasmic perception. A vast majority of men with both complete and incomplete SCI will require treatment for ED, and the therapeutic options should include sexual counseling so that the patient can be informed about his disorder and can adjust his sexual behavior accordingly. The first-line treatment of choice is oral drugs, such as phosphodiesterase inhibitors (sildenafil, tadalafil, and vardenafil). Sildenafil has been shown to be highly effective and well tolerated in men with ED of various etiologies, including SCI. Data are also presented on sublingual apomorphine, which has limited indications for the treatment of ED in SCI, and on constrictive rings and vacuum systems. Second-line treatments include intracavernous injections of prostaglandin E(1), papaverine, and phentolamine, alone or in combination, which have been shown to be highly effective in the treatment of ED in men with SCI. Finally, for third-line treatments, the indications for surgical methods are given, including penile prostheses and neuroprosthesis of anterior sacral roots. These devices should be reserved for the cases when the above-mentioned methods have repeatedly failed. Historically, the treatment of ED among patients with SCI has been managed by clinicians in physical medicine and rehabilitation. Thus, the criteria for referral and the competencies of these specialists are established, and they should be included as an integral part of the rehabilitation program.

Feline penile erection induced by topical glans penis application of combination alprostadil and SEPA (Topiglan)

The objective of this study was to evaluate the efficacy of topically applied prostaglandin E1 (PGE(1))+5% SEPA (soft enhancement of percutaneous absorption) on the glans penis in a feline erection model. Erectile response after glans penis administration of PGE(1)+5% SEPA cream (Topiglan, MacroChem Co., Lexington, MA, USA) was compared to the erectile response after intracavernosal administration of the triple-drug combination (1.65 mg papaverine, 25 microg phentolamine, and 0.5 microg PGE(1)). The placebo cream and increasing concentrations (0.25%, 2.5 mg/ml; 0.5%, 5 mg/ml; and 1%, 10 mg/ml) of PGE(1)+5% SEPA were applied in a total volume of 0.1 ml via a plastic needle-less syringe. The control triple-drug combination was administrated intracavernosally via a 30-gauge needle at the completion of each experiment to serve as a control reference. With each application of placebo, PGE(1)+SEPA, and the triple-drug combination, changes in intracavernosal pressure and systemic blood pressure were continuously monitored. Topical application of PGE(1)+SEPA induced increases in intracavernosal pressure in a dose-dependent manner, with minimal effects on systemic blood pressure. The increases obtained with 1% PGE(1) Topiglan cream were similar to the intracavernosal pressure values elicited by the standard intracavernosal triple-drug combination. These data demonstrate that topical glans penis application of PGE(1)+SEPA can induce an erectile response in cats with minimal systemic adverse effects. Oral pharmacological agents are the first-line treatment for male ED. Studies investigating the effectiveness of noninvasive modalities such as topical therapy should continue, because these agents have the potential to avoid the systemic effects commonly seen with oral therapies. Additionally, topical therapy may also benefit patients who are unresponsive to oral agents or have explicit contraindications. Topical PGE(1) application to the glans penis may become an important treatment option in selected patients suffering from erectile dysfunction.