Comparative evaluation of naftopidil and tamsulosin in the treatment of patients with lower urinary tract symptoms with benign prostatic hyperplasia

Abstract

Introduction:Naftopidil, approved initially in Japan, is an α1d-adrenergic receptor antagonist (α1-blocker) used to treat lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). It is different from tamsulosin hydrochloride and silodosin, in that it has a higher affinity for the α1D-adrenergic receptor subtype than for the α1A subtype and has a superior efficacy to a placebo and comparable efficacy to other α1-blockers such as tamsulosin. The incidences of ejaculatory disorders and intraoperative floppy iris syndrome induced by naftopidil may also be lower than that for tamsulosin and silodosin, which have a high affinity for the α1A-adrenergic receptor subtype. However, it remains unknown if the efficacy and safety of naftopidil in Japanese men is applicable to Indian men having LUTS/BPH.Material and Methods:Two groups of 60 patients each, having LUTS due to BPH, were treated with tamsulosin 0.4 mg and Naftopidil 75 mg for three months. Ultrasonography (for prostate size, post-void residual volume), uroflowmetry, and the International Prostate Symptom Score (IPSS) and Quality of Life (QOL) score were recorded at the beginning of the study, and then at one and three months.Results:The prostate size, post-void residual volume, all the uroflowmetry variables, and the IPSS QOL scores showed a statistically significant improvement (P < 0.001) in both the groups. The improvement in the average flow rate and the QOL index was better in the naftopidil group on the intergroup comparison and was statistically significant (P < 0.001).Conclusion:Although the QOL life index was significantly better in the naftopidil group, overall both naftopidil and tamsulosin were found to be equally effective in the treatment of LUTS due to BPH.

Characterization on Responsiveness of Excitatory Synaptic Transmissions to α1-Adrenoceptor Blockers in Substantia Gelatinosa Neurons Isolated From Lumbo-Sacral Level in Rat Spinal Cords

“…Differences among α1-adrenoceptor blockers with respect to the degree of efficacy in male LUTS have been controversial. Gotoh et al reported that naftopidil is as effective as tamsulosin on the symptom basis using the International Prostate Symptom Score [26,27]. Nishino et al [28] reported that maximum desired volume and first desired volume were higher with naftopidil than with tamsulosin in a pressure flow study.…”

Add-on Therapy With the α-Blockers Tamsulosin and Naftopidil Improves Voiding Function by Enhancing Neuronal Activity in Prostatic Hyperplasia Rats

“…Naftopidil has a 3 fold higher affinity for the α1DARsubtype than for the α1A-AR subtype, and naftopidil shows different effects on lower urinary tract symptoms because many α1D-ARs exist in the bladder neck [ 17 ]. Both α1-AR subtype antagonists alleviate bladder outlet obstruction symptoms, such as residual urine and urinary urge sensation, by reducing the prostate size [ 18 ]. Overactive bladder symptoms, including frequency, urgency, nocturia, and urgency incontinence, were decreased by α1-AR antagonists in clinical and animal studies [ 12 , 19 ].…”

Effects of Combination Treatment of Alpha 1-Adrenergic Receptor Antagonists on Voiding Dysfunction: Study on Target Organs in Overactive Bladder Rats

“…Meanwhile, naftopidil has a 3-fold affinity for the α 1 D-AR subtype rather than the α 1 A-AR subtype, and naftopidil shows different characteristics on LUTS, because major α 1 DAR exists in the bladder neck [10]. Both α 1 -AR subtype antagonists alleviate OAB-related symptoms, such as frequent micturition and urinary urge sensations [11]. Frequency, urgency, nocturia, and urgency incontinence were decreased by α 1 -AR antagonists in clinical research [12].…”