Does tadalafil prevent erectile dysfunction in patients undergoing radiation therapy for prostate cancer?

A recently published paper addressed the interesting topic of prevention of erectile dysfunction (ED) with tadalafil, a phosphodiesterase-type 5 inhibitor (PDE5i) in patients undergoing radiation therapy for localized prostate cancer.1 Tadalafil 5 mg or placebo was administered once-daily for 24 weeks in patients undergoing external-beam radiotherapy (EBRT) or brachytherapy (BT) for prostate cancer. This randomized trial did not show superior efficacy of the active drug compared with placebo 4–6 weeks after stopping the study drug. Furthermore, patients younger than 65 years did not respond significantly better than older patients.