Current status of intracavernosal injection therapy in erectile dysfunction

ABSTRACT

Introduction

Erectile dysfunction (ED) is defined as the inability to attain and/or maintain a penile erection. The first introduction of intracavernosal injection (ICI) for the treatment of erectile failure was in 1982 by Virag who reported the positive effects of papaverine on erectile tissue, followed by Brindley concurrently conducting research on ICI therapy with alpha-blockade. ICI remains a viable option for the treatment of ED, even after FDA approval of phosphodiesterase type 5 inhibitors in 1998. The American Urological Association (AUA) and the European Association of Urology (EAU) both recommend ICI as a second-line therapy for the treatment of ED. We herein provide an overview of the current state of ICI therapy for the treatment of ED.

Areas covered

We performed a literature review from 1977–2022, using PubMed and the current AUA and EAU guidelines to discuss the current state of ICI for the treatment of ED.

Expert opinion

Although other oral agents are considered first line for the treatment of ED, the current guidelines and literature demonstrate that ICI is a safe and effective option for patients; however, careful patient selection and counseling should be performed to maximize the effectiveness and safety of this ED treatment.

KEYWORDS:

• Erectile dysfunction
• intracavernosal injection
• alprostadil
• papaverine
• phentolamine
• Bimix
• Trimix
• Quadmix

Article highlights

• ED is defined as the consistent or recurrent inability to attain and/or maintain a penile erection sufficient for satisfactory sexual performance.

• We have performed a literature review from 1977-2022, using PubMed and the current AUA and EAU guidelines to discuss the current state of ICI therapy for the treatment of ED.

• The AUA and EAU both recommend ICI as a second-line therapy for the treatment of ED after the use of PDE5 inhibitors. Of note, alprostadil is the only ICI therapy currently FDA approved for ED.

• Although combination therapy with Bimix, Trimix, and Quadmix have proven their efficacy, there is currently no FDA approval for any of these agents, making dosing and standardization of treatment difficult. Despite this, after review of the guidelines and literature regarding treatment for ED, it is clear that ICI is an effective treatment option for patients experiencing significant ED.

• Future directions for these agents are the FDA approval and standardization of dosing.

Acknowledgments

The authors wish to thank Scott Bailey, PhD, Department of Urology, Tulane University School of Medicine, for editing and preparing this manuscript.

Declaration of interest

W.J.G.H. reports being a Consultant for Acerus Pharma, Boston Scientific, Coloplast, Endo, and Jazz Pharmaceuticals; and an Advisory Board Member for Gilead, Maximus, Promescent, and Theralogix. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Abbreviations (in order of use)

1. erectile dysfunction – ED

2. intracavernosal injection – ICI

3. American Urological Association – AUA

4. guanylate cyclase – GC

5. smooth muscle – SM

6. cyclic guanosine monophosphate – cGMP

7. phosphodiesterase – PDE

8. phosphodiesterase type 5 – PDE5

9. European Association of Urology – EAU

10. adenylate cyclase – AC

11. cyclic adenosine monophosphate – cAMP

12. prostaglandin E1 - PGE1

13. molecular weight – MW

14. mechanism of action – MOA

15. prostaglandin – PG

16. adrenergic receptor – AR

17. area under the curve – AUC

18. maximum concentration – Cmax

19. volume of distribution – VOD

20. International Index of Erectile Function – IIEF-5

21. liver function tests – LFTs

22. stem cell – SC

Additional information

Funding

This paper was not funded.