Efficacy Of Testosterone Replacement Therapy Plus Alternate-Day Tadalafil For Patients With Late-Onset Hypogonadism: An Open-Label, Randomized, Crossover Study

Objective To examine the efficacy and safety of combination treatment with testosterone replacement therapy plus alternate-day tadalafil (10 mg) in patients with late-onset hypogonadism.Methods In this open-label, randomized, crossover study, 29 patients with late-onset hypogonadism were randomly assigned to receive testosterone replacement therapy for 12 weeks followed by combination treatment for 12 weeks (Group 1) or combination treatment for 12 weeks followed by testosterone replacement therapy (Group 2). Symptom questionnaires were administered and blood tests were performed prior to and following each treatment to assess safety and efficacy. At the end of the study, participants were asked about their treatment preferences.Results An adverse effect, a rheum symptom, occurred in only one participant, and 26 participants completed the study without any toxicity. Scores on the Aging Male Symptoms scale and the modified short version of the International Index of Erectile Function, and Overactive Bladder Symptom scores were significantly improved in the combination treatment phase of Group 2, whereas no significant difference between the phases were observed in Group 1. In total, 12 out of the 14 participants in Group 1 and 11 out of the 12 participants in Group 2 preferred combination treatment, which reached statistical significance (P = 0.008 and 0.004 for Groups 1 and 2, respectively).Conclusions Testosterone replacement therapy with add-on alternate-day tadalafil is a safe and satisfactory treatment for patients with late-onset hypogonadism.