Activity of phosphodiesterase type 5 inhibitors in patients with lower urinary tract symptoms due to benign prostatic hyperplasia

Level of Evidence 1b What's known on the subject? and What does the study add? Phosphodiesterase type 5 inhibitors (PDE 5Is) improve erectile function and lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH), however the exact effects on prostate tissue and its underlying mechanisms remain unclear. PDE 5Is enhanced the production of cyclic nucleotides in the plasma and prostate, and the distribution of PDE 5Is in the prostate was higher than in the plasma. OBJECTIVE center dot To evaluate the impact and distribution of a single phosphodiesterase type 5 inhibitor (PDE5 I) dose (udenafil or tadalafil) in prostate tissue and plasma in patients with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS center dot Thirty BPH patients complaining of erectile dysfunction along with moderate-to-severe lower urinary tract symptoms (LUTS) who underwent transurethral resection of the prostate (TURP) were enrolled in the present study. center dot The patients were randomly divided into the three groups: group 1, TURP without PDE5 Is; group 2, 200 mg of udenafil given 1 h before TURP; and group 3, 20 mg of tadalafil given 1 h before TURP. center dot We evaluated the concentrations of PDE5-I, cAMP and cGMP in prostate tissues and plasma, and calculated the prostate tissue-to-plasma (T/P) ratio. RESULTS center dot The concentration of udenafil in prostate tissue and plasma was 2028.6 +/- 360.8 ng/g and 463.7 +/- 39.1 ng/mL, respectively, and the resulting T/P ratio was 4.4. The tadalafil concentration in prostate tissue and plasma was 385.7 +/- 83.8 ng/g and 305.8 +/- 41.1 ng/mL, respectively, and the T/P ratio was 1.3. center dot Udenafil and tadalafil significantly increased the cAMP and cGMP levels in plasma and prostate tissues. CONCLUSIONS center dot Udenafil and tadalafil significantly increased cAMP and cGMP levels and were more highly distributed in the prostate than plasma. The T/P ratio of udenafil was higher than tadalafil. center dot These findings may help in the assessment of the feasibility of using PDE5 Is to concurrently treat both LUTS and erectile dysfunction.