Efficacy of tadalafil and l-arginine combination therapy compared with tadalafil-only for the treatment of erectile dysfunction: A systematic review and meta-analysis

Abstract

Introduction: Phosphodiesterase type 5 inhibitors (PDE5-I) has known to be the treatment for erectile dysfunction (ED), whereas tadalafil is a PDE5-I that has a rapid onset of action with a long duration of action and is not affected by dietary intake. L-arginine is a supplement that can improve erectile function by increasing the endogenous amino acids required for ideal nitric oxide (NO) synthesis and production. The combination of tadalafil and L-arginine can improve erectile function and testosterone levels. Thus, we conducted a meta-analysis to determine the efficacy and safety of the tadalafil and L-arginine combination therapy compared to tadalafil monotherapy for ED. Methods: This meta-analysis study is consistent with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A total of four included studies were found by performing a systematic search thoroughly on Embase, MEDLINE, and Scopus databases. This study’s protocol is registered on PROSPERO (CRD42022343590). Result: The study analysis revealed that the The International Index of Erectile Dysfunction 5 (IIEF-5) scores in the tadalafil and L-arginine combination therapy significantly increased the IIEF-5 scores (p < 0.00001; MD 1.64; 95% CI: 1.13-2.15) compared to tadalafil monotherapy. Testosterone levels were also observed to increase in the tadalafil and L-arginine combination therapy group (p < 0.00001; MD 3.05; 95% CI: 2.05-4.04). Conclusion: A significant increase in IIEF-5 score and testosterone level is observed in patients with ED who received combination therapy of tadalafil and L-arginine compared to tadalafil monotherapy.