α1D/A‐adrenoceptor antagonist naftopidil for the male lower urinary tract symptoms associated with benign prostatic hyperplasia: Efficacy of dose increase therapy

Abstract

Abbreviations & AcronymsObjectives: To examine the efficacy of dose increase therapy in patients with lower urinary tract symptoms associated with benign prostatic hyperplasia who responded poorly to 50 mg/day of naftopidil. Methods: A total of 95 patients received 50 mg/day of naftopidil for 8 weeks. After this treatment period, they were divided into two groups: the poor responders were defined as those who either had an International Prostate Symptom Score-Quality of Life Ն4 or with an International Prostate Symptom Score-Quality of Life of 3 whose International Prostate Symptom Score-Quality of Life improved <2 points (group A). All other patients were defined as responders to naftopidil 50 mg/day (group B). The dose of naftopidil was increased to 75 mg/day in group A, and maintained at 50 mg/day in group B. The treatment was continued for a further 8 weeks. Results:The prostate volume at the baseline was significantly larger in group A than group B. The improvement of International Prostate Symptom Score total score, International Prostate Symptom Score-Quality of Life, and voided volume after 8 weeks was significantly better in group B than in group A. However, there was no significant difference in the changes of all parameters between the two groups after 16 weeks. Conclusions: A dose increase to 75 mg/day is an effective treatment strategy in patients with lower urinary tract symptoms associated with benign prostatic hyperplasia who responded poorly to an initial dose of 50 mg/day of naftopidil. Furthermore, a starting dose of 75 mg/day should be considered in patients with a large prostate volume, as this is a predictive factor for dose increase.

The predictive factors of α1-D/A adrenoceptor antagonist, naftopidil, dose increase therapy for male lower urinary tract symptoms caused by benign prostatic hyperplasia: INFORM study

“…[ 9 ] Recently, the efficacy of naftopidil dose increase therapy from 50 to 75 mg/day was evaluated for the patients who were ineffective in 50 mg/day. [ 10 11 ] However, it is unknown about the predictive factors which affect the efficacy of naftopidil dose increase therapy. Hence, we examined the predictive factors which affect the efficacy of naftopidil short-term therapy and dose increase therapy.…”

“…There were some reports that the effective ratio of naftopidil monotherapy for 8∼12 weeks were 50.8%, 52.5% and 68.6%. [ 10 11 12 ] Therefore, it thought that this result was appropriate. Nevertheless, Mizusawa et al .…”

Editorial Comment from Dr Park to α1D/A‐adrenoceptor antagonist naftopidil for the male lower urinary tract symptoms associated with benign prostatic hyperplasia: Efficacy of dose increase therapy

“…Yamaguchi et al . showed that the dose increase to 75 mg/day in the patients who were responding poorly to 50 mg/day of naftopidil was a useful therapy of choice before switching to another α1‐blocker . There was no increase of the incidence of adverse events, even when the drug was increased in dosage.…”

Editorial Comment from Dr Ishizuka to α1D/A‐adrenoceptor antagonist naftopidil for the male lower urinary tract symptoms associated with benign prostatic hyperplasia: Efficacy of dose increase therapy

“…Yamaguchi et al . are to be congratulated for their well‐structured and consequently highly evaluated work on the efficacy of dose increase therapy with the α1D/A‐adrenoceptor antagonist, naftopidil, for the male lower urinary tract symptoms associated with benign prostatic hyperplasia.…”