Determination of the Efficiency of 8 mg Doxazosin XL Treatment in Patients With an Inadequate Response to 4 mg Doxazosin XL Treatment for Benign Prostatic Hyperplasia

Objective To compare the efficacy of 4 mg and 8 mg doxazosin XL treatments in patients with benign prostatic hyperplasia–related lower urinary tract symptoms and determine the efficiency of 8 mg in those patients with inadequate response to 4 mg. Methods A total of 162 patients were included in this study. Of the patients, 108 were randomized to receive 4 mg doxazosin XL (group 1), and 54 were randomized to receive 8 mg (group 2) treatments. After 1 month of treatment, 31 patients in group 1 whose quality of life (QoL) score was unchanged or had deteriorated were switched to 8 mg doxazosin XL treatment (group 1b). Results The mean age was 59.8 years. After 1 month of treatment, the mean alteration in the International Prostate Symptom Score was 3.9 and 5.2 ( P  = .028), for the maximum urinary flow rate (Q max ), it was 3.0 and 3.6 mL/s ( P  = .206), and for the QoL score it was 1.3 and 1.7 ( P  = .038) in groups 1 and 2, respectively. For group 1b, during the period in which the patients were receiving 4 and 8 mg doxazosin XL treatments; the International Prostate Symptom Score changes were 1.3 and 3.6 ( P max changes were 1.6 and 3.2 mL/s ( P P Conclusion With no changes in side effects, 8 mg doxazosin XL treatment is an efficient choice for patients who did not have an adequate response to 4 mg doxazosin XL treatment.