The aim of this systematic review and meta-analysis is provide an answer whether a combined treatment with alpha blocker and phosphodiesterase-5 inhibitor is safe or not.
The study is conducted according to the PRISMA statement. The included studies are only randomized controlled trials, which have at least one group on alpha blocker monotherapy and one group on a combined treatment with an alpha blocker and a phosphodiesterase-5 inhibitor. The primary endpoint were the hemodynamic effects of the two groups and specifically the clinically significant changes and the positive orthostatic test. The secondary endpoint were the adverse events of the two treatment modalities.
Following the screening of 6687 studies, it was decided that 19 randomized controlled trials were eligible for the meta-analysis. The combined treatment provoked more often a clinically significant hemodynamic change with a MD of 4.73 (CI: 1.25, 17.94; I2=0%; p=0.02), but the positive orthostatic test was similar between the groups with a MD of 1.64 (CI: 0.36, 7.47; I2=50%; p=0.52). The meta-analysis for the adverse events was in favor of alpha blocker monotherapy with an OD of 0.5 (CI: 0.32, 0.78; I2=44%; p=0.002), but if we consider only the adverse events due to hypotension, the result is similar between the two groups with OD of 0.97 (CI: 0.58, 1.64; I2=0%; p=0.92).
Despite the fact the combined treatment may occur a clinically significant hemodynamic change, the combination of alpha blocker and phosphodiesterase-5 inhibitor is considered safe, because it does not increase the rate of adverse events due to hypotension.