Naftopidil

Naftopidil (Flivas), a selective α1-adrenergic receptor antagonist or alpha blocker, is an antihypertensive drug.Naftopidil significantly improved the overall international prostatic symptom score ; from 19.2±7.9 to 11.7±5.8 in the M group and from 19.4±6

Efficacy and Safety of Naftopidil in the Medical Expulsion Therapy for Distal Ureteral Stone: A Systematic Review and Meta-Analysis.[Pubmed:28306333]

J Endourol. 2017 May;31(5):427-437.

PURPOSE: The selective alpha-adrenoceptor blocker is widely used as a cost-effective treatment option for medical expulsive therapy (MET) of ureteral stones. In this review, we aimed to assess the efficacy and safety of Naftopidil for MET compared with control or tamsulosin. METHODS: A systematic literature search was performed in PubMed, Cochrane Library, Embase, and Google Scholar to identify randomized controlled trials that compared Naftopidil with either control or tamsulosin for the management of distal ureteral stones. RESULTS: We included 7 publications with 553 patients. Naftopidil was not only effective for distal ureteral calculi but also was comparable to tamsulosin in efficacy. The expulsion rate (risk ratio [RR] 2.00, 95% confidence interval [CI] 1.41, 2.83; P < 0.0001) and expulsion time (days) of distal ureteral stones (mean difference [MD] -1.72, 95% CI -3.27, -0.18, P = 0.03) indicated that Naftopidil was more effective than control. Based on the expulsion rate (RR 1.05, 95% CI 0.74, 1.48; P = 0.80), expulsion time (days) (MD 0.18, 95% CI -0.49, 0.85; P = 0.59), and number of pain episodes (P = 0.87), Naftopidil was comparable to tamsulosin. A little lower adverse effect rate was observed with Naftopidil compared with tamsulosin (RR 0.47, 95% CI 0.23, 0.94; P = 0.03). CONCLUSIONS: In terms of efficacy for distal ureteral calculi, Naftopidil would be superior to control and comparable to tamsulosin; moreover, the safety profile of Naftopidil might be superior to that of tamsulosin. We conclude that Naftopidil might be a powerful candidate in MET for distal ureteral stones.

Ketanserin and Naftopidil Enhance the Potentiating Effect of Alpha-Methyl-Serotonin on the Neurally-Induced Contraction of Human Isolated Urinary Bladder Muscle Strips.[Pubmed:28361518]

Int Neurourol J. 2017 Mar 24;21(1):20-28.

PURPOSE: The aim of this study was to assess the potential involvement of a specific subtype of 5-hydroxytryptamine (5-HT), 5HT2 receptors in neurally-induced contractions of the human detrusor. METHODS: Contractile responses to electrical field stimulation (EFS) were examined in human isolated urinary bladder muscle strips. The potentiation of EFS-induced detrusor contraction was examined by adding cumulative concentrations of a 5-HT and 5-HT2 receptor agonist, alpha-methyl-serotonin (alpha-Me-5-HT) (1nM-100muM) in the presence or absence of a 5-HT2 antagonist, ketanserin (5-HT2A>5-HT2C) or Naftopidil (5-HT2B>5-HT2A) (0.3-3muM). RESULTS: 5-HT and alpha-Me-5-HT potentiated EFS-induced contraction with a maximal effect (Emax) of 37.6% and 38.6%, respectively, and with pEC50 (negative logarithm of the concentration required for a half-maximal response to an agonist) values of 8.3 and 6.8, respectively. Neither ketanserin nor Naftopidil at any concentration produced a rightward displacement of the alpha-Me-5-HT concentration response curve. Instead, the Emax of alpha-Me-5-HT increased in the presence of ketanserin at 0.3-1muM and in the presence of Naftopidil at 1muM to 51% and 56%, respectively, while the Emax in the presence of vehicle alone was 36%. The highest concentration (3muM) of either drug, however, fully reversed the enhancement. CONCLUSIONS: The potentiating effect of alpha-Me-5-HT on neurally-induced contraction of human urinary bladder muscle strips was not found to be mediated via any 5-HT2 receptor subtypes. The underlying mechanism for the enhancement of the alpha-Me-5-HT potentiating effect on detrusor contractility by ketanserin and Naftopidil remains unknown; however, our results suggest that these drugs may be useful for treating contractile dysfunction of the detrusor, as manifested in conditions such as underactive bladder.

Combination treatment with naftopidil increases the efficacy of radiotherapy in PC-3 human prostate cancer cells.[Pubmed:28243746]

J Cancer Res Clin Oncol. 2017 Jun;143(6):933-939.

PURPOSE: Clinically, radiotherapy (RT) often leads to the development of prostate cancer (PCa) resistance because of protective responses in cancer cells. One of the mechanisms includes the upregulation of RT-induced antioxidant enzymes. Thus, combination therapy with RT and certain pharmaceutical drugs targeting antioxidant enzymes may be ideal for increasing the efficacy of RT with minimum side effects. Naftopidil is a subtype-selective alpha1D-adrenoceptor antagonist used for the treatment of benign prostatic hyperplasia (BPH). In our drug repositioning study, Naftopidil showed not only unique growth-inhibitory effects but also AKT phosphorylation-inhibitory effects in PC-3 human PCa cells. Here, we examined the efficacy of additive Naftopidil treatment in combination with RT in PC-3 cells. METHODS: The effects of combination therapy with RT plus Naftopidil were analyzed using an animal model of PC-3 xenografts in BALB/c nude mice. The expression of the antioxidant enzyme manganese superoxide dismutase (MnSOD) was evaluated by western blotting. RESULTS: Combination therapy with RT plus Naftopidil induced a more efficacious delay in PC-3 xenograft tumor growth as compared with monotherapy with Naftopidil or RT. In PC-3 tumors, combination therapy with RT plus Naftopidil suppressed the upregulation of RT-induced MnSOD expression. In vitro, neither AKT inhibitor IV nor Naftopidil directly altered MnSOD expression. Upregulation of RT-induced MnSOD expression was markedly suppressed by combination treatment with RT plus AKT inhibitor IV or Naftopidil. CONCLUSIONS: These results suggest that additive Naftopidil treatment in combination with RT may increase the efficacy of RT for the treatment of PCa.

Pharmaceutical evaluation of naftopidil enantiomers: Rat functional assays in vitro and estrogen/androgen induced rat benign prostatic hyperplasia model in vivo.[Pubmed:27615445]

Eur J Pharmacol. 2016 Nov 15;791:473-481.

Naftopidil (NAF) is a alpha1D/1A adrenoceptor selective drug used for the treatment of both benign prostatic hyperplasia and lower urinary tract symptoms (BPH/LUTS). However, NAF is used as a racemate in clinic. To compare the differences and similarities among two enantiomers and racemate, pharmacological activities were evaluated through rat functional assays in vitro and estrogen/androgen (E/T) induced rat BPH model in vivo. NAF and the two enantiomers showed similar blocking activity on alpha1 receptor. S-NAF exhibited more alpha1D/1A adrenoceptor subtype selectivity than R-NAF and the racemate. The selectivity ratios pA2 (alpha1D)/pA2 (alpha1B) and pA2 (alpha1A)/pA2 (alpha1B) were 40.7- and 16.2-fold, respectively. NAF and its enantiomers effectively prevented the development of rat prostatic hyperplasia via suppressing the increase of the prostatic wet weight, visually. The quantitative analysis of the relative acinus volume, relative stroma volume, relative epithelial volume, epithelial height and expression of proliferating cell nuclear antigen (PCNA) and alpha-smooth muscle actin (alpha-SMA) were carried out. S-NAF showed an advantage on the effect of inhibiting prostate wet weight and stroma volume over R-NAF and racemate NAF (P<0.05). Nevertheless, no other significant difference was observed between these two enantiomers. In conclusion, both R-NAF and S-NAF not only relax prostate muscle but also inhibit the prostate growth, thus relieve BPH.