Usefulness of tamsulosin hydrochloride and naftopidil in patients with urinary disturbances caused by benign prostatic hyperplasia: A comparative, randomized, two‐drug crossover study

Abstract

Background : The aim of the study presented here was to stratify drug therapy for patients with benign prostatic hyperplasia (BPH) displaying various voiding symptoms. Methods : Two different a 1-adrenoceptor antagonists; tamsulosin hydrochloride (Tam) and naftopidil (Naf ), were administered to 96 patients with BPH for 8 weeks in a crossover study.Results : With the administration of both drugs, the International Prostate Symptom Score (I-PSS) significantly decreased and the maximum urinary flow significantly increased. Whereas Naf monotherapy decreased the I-PSS for storage symptoms, Tam monotherapy decreased the I-PSS for voiding symptoms. In both the Naf-to-Tam and Tam-to-Naf groups, crossover was effective when the initial drug was judged subjectively and objectively to have been ineffective. Compliance was acceptable with both drugs. Conclusion : Our results show that either Naf or Tam can be used to treat patients on the basis of objective and subjective assessment of voiding symptoms. Our findings should be helpful for patient guidance and treatment of BPH.

Management of benign prostatic hyperplasia with silodosin

“…In a cross-over study comparing tamsulosin (α 1A -AR  α 1D -AR) with naftopidil (α 1D -AR  α 1A -AR), relief of storage symptoms was significantly better in subjects given naftopidil. 1,[51][52][53][54] However, this issue is still controversial and different results have been reported by other authors. 1,55,56 Recently, Kira and colleagues 57 studied the efficacy of silodosin in 85 patients with LUTS/BPH who were resistant to tamsulosin (n = 39) or naftopidil (n = 46), and reported a rapid and significant decrease in scores of decreased urinary stream and nocturia (both p  0.01), which were the most bothersome symptoms among IPSS.…”

LUTS treatment: Future treatment options

“…This observation is of particular interest considering the findings that in the human spinal cord, a 1D -AR mRNA predominated overall. 39 In an 8-week crossover study of tamsulosin and naftopidil monotherapy given to 96 patients with BPH, Ikemoto et al 40 found that naftopidil significantly decreased the International Prostate Symptom Scores (IPSS) for storage symptoms and tamsulosin decreased the IPSS for voiding symptoms. However, this difference (which was suggested to depend on differences in affinity for a 1 -AR subtypes between the drugs) could not be reproduced in a randomized head-to-head comparison between the drugs.…”

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

“…7,10 Likewise, the treatment strategy of switching from one a1-blocker to another has become possible and allows the utilization of the different characteristics of a1A-AR selective blockers when the 50 mg/day dosage of naftopidil is found to be ineffective. 10 However, it has been reported that the adverse events, such as ejaculate dysfunction 19,20 or sexual dysfunction, 21 and the incidence of intraoperative floppy iris syndrome are higher with a1A-AR selective blockers, such as tamsulosin or silodosin, than naftopidil. 22 Thus, it might be suggested that the dose increase to 75 mg/day in patients with LUTS/BPH who are responding poorly to 50 mg/day of naftopidil used as the first-line drug is a useful therapy of choice before switching to another a1-blocker.…”

“…[6][7][8] Another feature of naftopidil is its flexible dose that allows the treatment strategy of selecting a dose suited to the patient's condition, severity of symptoms and increasing the dose if the initial dosage is ineffective. 9 Although naftopidil is usually administered at 50 mg/day, 7,10 the efficacy of 75 mg/day administration has been recently reported. [11][12][13][14] 50 mg/day based on the IPSS-QoL index, the dosage was maintained at 50 mg/day in the responders, but was increased to 75 mg/day in the poor responders.…”