A Meta-Analysis of Long- Versus Short-Acting Phosphodiesterase 5 Inhibitors: Comparing Combination Use With α-Blockers and α-Blocker Monotherapy for Lower Urinary Tract Symptoms and Erectile Dysfunction

Purpose: Combination therapy with an a-1-adrenergic blocker and phosphodiesterase type 5 inhibitors (PDE5Is) has shown improvements in lower urinary tract symptoms (LUTS) with negligible side effects. Nonetheless, decisive advantages in symptom improvement were insufficient, and there were no clinical differences between long- or short-acting PDE5Is in combination with combination medication. Methods: To review the studies on α-1-adrenergic blocker monotherapy and combination therapy with long vs. short-acting PDE5Is in their use in LUTS and erectile dysfunction (ED). A search of the MEDLINE, Embase, Cochrane Library, and KoreaMed databases was conducted from 2000 to 2014 using combinations of the relevant terms. Among the 323 relevant references discovered, 10 were selected for meta-analysis. The data showed that 616 men received combination therapy (PDE5Is with α-1-adrenergic blockers) or α-1-adrenergic blocker monotherapy. Results: Meta-analysis of the combination therapy showed it was more effective than α-blockers in improving symptoms, with a mean International Prostrate Symptom Score change difference of -1.93 while those of the long- vs. short-acting PDE5I were -2.12 vs. -1.70. Compared to maximum flow rate (Qmax) value with monotherapy, the Qmax increased more with the combination therapy (mean difference of 0.71) while change values were 0.14 and 1.13 for the long- and short-acting PDE5Is, respectively. Residual urine decreased more with the combination therapy than it did with α-1-adrenergic blocker monotherapy with a mean difference of -7.09 while the mean residual urine change values for long- vs. short-acting PDE5Is were -18.83 vs. -5.93. The International Index of Erectile Function value increased by 3.99, 2.85, and 4.85 following combination therapy, and therapy with long- and short-acting PDE5Is. Conclusions: Our meta-analysis suggests that PDE5Is can significantly improve LUTS in men with benign prostatic hyperplasia/ ED. Furthermore, combination PDE5I and α-1-adrenergic blocker could be a more effective treatment than α-1- adrenergic blocker monotherapy, and the differences between long and short-acting agents were minimal.