Effects of daily low-dose treatment with phosphodiesterase type 5 inhibitor on cognition, depression, somatization and erectile function in patients with erectile dysfunction: A double-blind, placebo-controlled study

Phosphodiesterase type 5 (PDE5) inhibitors have recently been shown to have cognitive-enhancing effects in animal models and in our previous pilot study. To investigate the efficacy of daily low-dose treatment with a PDE5 inhibitor on cognitive function, depression and somatization in patients with erectile dysfunction (ED), 8-week, double-blind, placebo-controlled study enrolled 60 male patients with ED for ≥3 months without cognitive impairment. Forty-nine patients completed the study. Patients were randomized to receive either daily low-dose udenafil 50 mg or placebo for 2 months. The International Index of Erectile Function-5 (IIEF-5), the Korean version of the Mini-Mental State Examination (K-MMSE) for general cognitive function and the Seoul Neuropsychological Screening Battery for comprehensive neuropsychological examination, the Physical Health Questionnaire-9 (PHQ-9) for depression and the Physical Health Questionnaire-15 (PHQ-15) for somatization were administered at baseline and at 2 months. The change in the mean IIEF-5 was significantly higher in the udenafil group than the placebo group (6.08±4.72 vs 2.20±3.50, P=0.008). The changes in the PHQ-9 and PHQ-15 were -2.04±3.14 and -2.17±2.87 in the udenafil group, and 1.20±1.63 and 0.56±2.48 in the placebo group (both, P<0.001). The changes in the K-MMSE and Digit Span Forward were 1.25±1.26 and 0.92±1.02 in the udenafil group, and -0.52±1.19 and -0.24±1.13 in the placebo group (both, P<0.001). However, there were no differences in the other neuropsychological tests. Daily dosing with a PDE5 inhibitor seems to improve cognitive function, depression and somatization, as well as erectile function, in patients with ED.