Doxazosin in the treatment of benign prostatic hypertrophy: an update

Alpha1-adrenergic blockers selectively antagonize the contractions induced by 6-nitrodopamine in the human vas deferens

6-Nitrodopamine (6-ND) is released from human vas deferens and plays a modulatory role in the male ejaculation. Therapeutical use of α1-adrenoceptor antagonists is associated with ejaculatory abnormalities. To evaluate the effect of α1-adrenoceptor antagonists on the contractions induced by 6-ND, dopamine, noradrenaline, and adrenaline in the human epididymal vas deferens (HEVD). HEVD strips were suspended in glass chambers containing heated and oxygenated Krebs-Henseleit's solution. Cumulative concentration-response curves to catecholamines (10 nM-300 μM) were constructed in HEVD strips pre-incubated (30 min) with doxazosin (0.1-1 nM), tamsulosin (1-10 nM), prazosin (10-100 nM) and/or silodosin (0.1-10 nM). The effects of these α1-adrenoceptor antagonists were also evaluated in the electric-field stimulation (EFS, 2-32 Hz)-induced contractions. Doxazosin (0.1 nM) caused significant reductions in 6-ND-induced HEVD contractions without affecting the contractions induced by dopamine, noradrenaline, and adrenaline. Similar results were observed with tamsulosin (1 nM) and prazosin (10 nM). At these concentrations, these α1-adrenoceptor antagonists largely reduced the EFS-induced contractions. Silodosin (1 nM) caused concentration-dependent rightward shifts of the concentration-response curves to 6-ND but had no effect on the contractions induced by dopamine and adrenaline. Silodosin (0.1 nM) only inhibited the contractions induced by noradrenaline. Silodosin at 1 nM, but not at 0.1 nM, caused significant reductions in the EFS-induced contractions. The results reinforce the concept that 6-ND plays a major role in the human vas deferens contractility and indicate that the ejaculation disorders caused by doxazosin, tamsulosin, prazosin and silodosin cause in man, may be due to inhibition of the contractions induced by 6-ND rather than by the classical catecholamines dopamine, noradrenaline, and adrenaline.

β1- and β1/β2-adrenergic receptor antagonists block 6-nitrodopamine-induced contractions of the rat isolated epididymal vas deferens

6-Nitrodopamine (6-ND) is an endogenous modulator of the contractility in the rat isolated epididymal vas deferens (RIEVD) and considered to be the main peripheral mediator of the emission process. Use of selective and unselective β-adrenergic receptor antagonists has been associated with ejaculatory failure. Here, the effects of selective β₁- and β₁/β₂-adrenergic receptor antagonists on RIEVD contractions induced by 6-ND, dopamine, noradrenaline, adrenaline, and electric-field stimulation (EFS) were investigated. The selective β₁-adrenergic receptor antagonists atenolol (0.1 and 1 µM), betaxolol (1 µM), and metoprolol (1 µM) and the unselective β₁/β₂-adrenergic receptor antagonists propranolol (1 and 10 µM) and pindolol (10 µM) caused significant rightward shifts of the concentration-response curve to 6-ND (pA₂ 6.41, 6.91, 6.75, 6.47, and 5.74; for atenolol, betaxolol, metoprolol, propranolol, and pindolol), but had no effect on dopamine-, noradrenaline-, and adrenaline-induced contractions. The effects of selective β₁- and β₁/β₂-adrenergic receptor antagonists at a higher concentration (atenolol 1 µM, betaxolol 1 µM, metoprolol 1 µM, propranolol 10 µM, and pindolol 10 µM) also reduced the EFS-induced RIEVD contractions in control, but not in RIEVD obtained from L-NAME-treated animals. The selective β₁-adrenoceptor agonist RO-363, the selective β₂-adrenoceptor agonist salbutamol, and the selective β₃-adrenoceptor agonist mirabegron, up to 300 µM, had no effect on the RIEVD tone. The results demonstrate that β₁- and β₁-/β₂-adrenoceptor receptor antagonists act as 6-ND receptor antagonists in RIEVD, further confirming the main role of 6-ND in the RIEVD contractility.

Alpha1-adrenergic antagonists block 6-nitrodopamine contractions on the rat isolated epididymal vas deferens

6-nitrodopamine (6-ND) is released from rat isolated vas deferens and modulates electrical-field stimulation (EFS) contractions of the rat isolated epididymal vas deferens (RIEVD) via a specific receptor which is blocked by tricyclic antidepressants. Here, the effects of selective α₁-adrenergic receptor antagonists on RIEVD contractions induced by 6-ND, dopamine, noradrenaline, adrenaline and EFS were investigated. Doxazosin and tamsulosin (3-10 nM) caused significant rightward shifts of the concentration-response curve to 6-ND, but had no effect on dopamine-, noradrenaline- and adrenaline-induced contractions. Alfuzosin (10 nM) produced rightward shifts on concentration-response curves to all catecholamines. Silodosin (10 nM) and terazosin (100 nM) displaced to the right the noradrenaline, dopamine and adrenaline curves, but higher concentrations of both antagonists (100 and 300 nM, respectively) were required to displace the 6-ND curves. The EFS-induced contractions were significantly inhibited only at the concentrations that the α₁-adrenergic receptor antagonists caused rightward shifts on the 6-ND concentration-response curves. The inhibition of EFS-induced contractions by doxazosin (10 nM), tamsulosin (10 nM), alfuzosin (10 nM), silodosin (100 nM) and terazosin (300 nM), were not observed in RIEVD obtained from animals chronically treated with L-NAME. This work demonstrates that α₁-adrenoceptor antagonists act as 6-ND receptor antagonists in RIEVD, opening the possibility that many actions previously attributed to noradrenaline could be due to 6-ND antagonism. In addition, blockade of the 6-ND receptors by both tricyclic antidepressants and α₁-adrenergic receptor antagonists may represent the common mechanism of action responsible for their therapeutic use in the treatment of premature ejaculation.

Anticholinergics combined with alpha-blockers for treating lower urinary tract symptoms related to benign prostatic obstruction

BACKGROUND

Lower urinary tract symptoms (LUTS) due to benign prostatic obstruction (BPO) represent one of the most common clinical complaints in men. Alpha-blockers are widely used as first-line therapy for men with LUTS secondary to BPO, but up to one third of men report no improvement in their LUTS after taking alpha-blockers. Anticholinergics used in addition to alpha-blockers may help improve symptoms but it is uncertain how effective they are.  OBJECTIVES: To assess the effects of combination therapy with anticholinergics and alpha-blockers in men with LUTS related to BPO.

SEARCH METHODS

We performed a comprehensive search of medical literature, including the Cochrane Library, MEDLINE, Embase, and trials registries, with no restrictions on the language of publication or publication status. The date of the latest search was 7 August 2020.

SELECTION CRITERIA

We included randomized controlled trials. Inclusion criteria were men with LUTS secondary to BPO, ages 40 years or older, and a total International Prostate Symptom Score of 8 or greater. We excluded trials of men with a known neurogenic bladder due to spinal cord injury, multiple sclerosis, or central nervous system disease, and those examining medical therapy for men who were treated with surgery for BPO. We performed three comparisons: combination therapy versus placebo, combination therapy versus alpha-blockers monotherapy, and combination therapy versus anticholinergics monotherapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the literature, extracted data, and assessed risk of bias. We performed statistical analyses using a random-effects model and interpreted data according to the Cochrane Handbook for Systematic Reviews of Interventions. We used the GRADE approach to rate the certainty of evidence.

MAIN RESULTS

We included 23 studies with 6285 randomized men across three comparisons. The mean age of participants ranged from 54.4 years to 73.9 years (overall mean age 65.7 years). Of the included studies, 12 were conducted with a single-center setting, while 11 used a multi-center setting. We only found short-term effect (12 weeks to 12 months) of combination therapy based on available evidence. Combination therapy versus placebo: based on five studies with 2369 randomized participants, combination therapy may result in little or no difference in urologic symptom scores (mean difference (MD) -2.73, 95% confidence interval (CI) -5.55 to 0.08; low-certainty evidence). We are very uncertain about the effect of combination therapy on quality of life (QoL) (MD -0.97, 95% CI -2.11 to 0.16; very low-certainty evidence). Combination therapy likely increases adverse events (risk ratio (RR) 1.24, 95% CI 1.04 to 1.47; moderate-certainty evidence); based on 252 adverse events per 1000 participants in the placebo group, this corresponds to 61 more adverse events (95% CI 10 more  to 119 more) per 1000 participants treated with combination therapy. Combination therapy versus alpha-blockers alone: based on 22 studies with 4904 randomized participants, we are very uncertain about the effect of combination therapy on urologic symptom scores (MD -2.04, 95% CI -3.56 to -0.52; very low-certainty evidence) and QoL (MD -0.71, 95% CI -1.03 to -0.38; very low-certainty evidence). Combination therapy may result in little or no difference in adverse events rate (RR 1.10, 95% CI 0.90 to 1.34; low-certainty evidence); based on 228 adverse events per 1000 participants in the alpha-blocker group, this corresponds to 23 more adverse events (95% CI 23 fewer to 78 more) per 1000 participants treated with combination therapy. Combination therapy compared to anticholinergics alone: based on three studies with 1218 randomized participants, we are very uncertain about the effect of combination therapy on urologic symptom scores (MD -3.71, 95% CI -9.41 to 1.98; very low-certainty evidence). Combination therapy may result in an improvement in QoL (MD -1.49, 95% CI -1.88 to -1.11; low-certainty evidence). Combination therapy likely results in little to no difference in adverse events (RR 1.26, 95% CI 0.81 to 1.95; moderate-certainty evidence); based on 115 adverse events per 1000 participants in the anticholinergic alone group, this corresponds to 4 fewer adverse events (95% CI 7 fewer to 13 more) per 1000 participants treated with combination therapy.

AUTHORS' CONCLUSIONS

Based on the findings of the review, combination therapy with anticholinergics and alpha-blockers are associated with little or uncertain effects on urologic symptom scores compared to placebo, alpha-blockers, or anticholinergics monotherapy. However, combination therapy may result in an improvement in quality of life compared to anticholinergics monotherapy, but an uncertain effect compared to placebo, or alpha-blockers. Combination therapy likely increases adverse events compared to placebo, but not compared to alpha-blockers or anticholinergics monotherapy. The findings of this review were limited by study limitations, inconsistency, and imprecision. We were unable to conduct any of the predefined subgroup analyses.

Impact of Geriatric Pharmacy Specialist Interventions to Reduce Potentially Inappropriate Medication Among Hospitalized Elderly Patients at Medical Wards: A Prospective Quasi-Experimental Study

Background

Elderly patients are at greater risk of receiving potentially inappropriate medications (PIMs) and developing adverse drug events. Identification and correction of PIMs is essential to maximize medication safety.

Objective

To determine the prevalence of PIMs on admission in Thai elderly patients admitted to a medical ward and to compare changes of PIMs on discharge, following comprehensive care by a ward pharmacist with or without a geriatric pharmacy specialist.

Patients and method

A prospective, quasi-experimental study was performed at a tertiary university hospital in Bangkok, Thailand. Patients aged ≥ 60 years who were admitted to the medical ward were recruited and allocated to one of two groups: intervention (IG) and control (CG). The CG received pharmaceutical care from the ward pharmacist. The IG received pharmaceutical care from the geriatric pharmacy specialist along with the ward pharmacist. The 2012 Beers criteria were used to identify PIMs on admission, during hospitalization, and on discharge.

Results

Prevalence of PIMs on admission was 43.3% (N = 187). On discharge, prevalence of PIMs in the IG decreased significantly compared to that on admission (21.3% and 43.3%, p < 0.05) and was significantly lower than in the CG (21.3% and 40.9%, p = 0.036). Moreover, the percentage of patients without PIMs on discharge in the IG was significantly higher than in the CG (78.7% and 59.1%, p < 0.0001).

Conclusion

Use of PIMs was common among hospitalized elderly patients on admission. Pharmaceutical care provided by a geriatric pharmacy specialist in conjunction with a ward pharmacist significantly reduced the prevalence of PIMs on discharge compared with on admission.

Naftopidil for the treatment of lower urinary tract symptoms compatible with benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) is a common condition in ageing men that may cause lower urinary tract symptoms (LUTS). Treatment aims are to relieve symptoms and prevent disease-related complications. Naftopidil is an alpha-blocker (AB) that has a high affinity for the A1d receptor that may have advantages in treating LUTS in this setting. This is an update of a Cochrane Review first published in 2009. Since that time, several large randomised controlled trials (RCTs) have been reported, making this update relevant.

OBJECTIVES

To evaluate the effects of naftopidil for the treatment of LUTS associated with BPH.

SEARCH METHODS

We performed a comprehensive search using multiple databases (the Cochrane Library, MEDLINE, Embase, Scopus, LILAC, and Web of Science), trials registries, other sources of grey literature, and conference proceedings with no restrictions on the language of publication or publication status up to 31 May 2018 SELECTION CRITERIA: We included all parallel RCTs. We also included cross-over design trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified and abstracted data from the included studies. We performed statistical analyses using a random-effects model and interpreted them according to the Cochrane Handbook for Systematic Reviews of Interventions. Primary outcomes were urological symptom scores, quality of life (QoL) and treatment withdrawals for any reason; secondary outcomes were treatment withdrawals due to adverse events, acute urinary retention, surgical intervention for BPH, and cardiovascular and sexual adverse events. We considered outcomes measured up to 12 months after randomisation as short term, and later than 12 months as long term. We rated the certainty of the evidence according to the GRADE approach.

MAIN RESULTS

We included 22 RCTs with 2223 randomised participants across four comparisons for short-term follow-up. This abstract focuses on only two of four comparisons for which we found data since two comparators (i.e. propiverine and Eviprostat (phytotherapy)) are rarely used. One study comparing naftopidil to placebo did not report any relevant outcomes and was therefore excluded. There were no trials that compared to combination therapy with naftopidil or any 5-alpha reductase inhibitors (5-ARIs) to combination therapy with other ABs and any 5-ARIs.All included studies were conducted in Asian countries. Study duration ranged from four to 12 weeks. Mean age was 67.8 years, prostate volume was 35.4 mL, and International Prostate Symptom Score was 18.3. We were unable to perform any of the preplanned subgroup analyses based on age and baseline symptom score.Naftopidil versus tamsulosinBased on 12 studies with 965 randomised participants, naftopidil may have resulted in little or no difference in urological symptom score (mean difference (MD) 0.47, 95% confidence interval (CI) -0.09 to 1.04 measured on a scale from 0 to 35 with higher score representing increased symptoms), QoL (MD 0.11, 95% CI -0.09 to 0.30; measured on a scale from 0 to 6 with higher scores representing worse QoL), and treatment withdrawals for any reason (risk ratio (RR) 0.92, 95% CI 0.64 to 1.34; corresponding to 7 fewer per 1000 participants, 95% CI 32 fewer to 31 more). Naftopidil may have resulted in little to no difference in sexual adverse events (RR 0.54, 95% CI 0.24 to 1.22); this would result in 26 fewer sexual adverse events per 1000 participants (95% CI 43 fewer to 13 more). We rated the certainty of evidence as moderate for urological symptom score and low for the other outcomes.Naftopidil versus silodosinBased on five studies with 652 randomised participants, naftopidil may have resulted in little or no difference in the urological symptom scores (MD 1.04, 95% CI -0.78 to 2.85), QoL (MD 0.21, 95% CI -0.23 to 0.66), and treatment withdrawals for any reason (RR 0.80, 95% CI 0.52 to 1.23; corresponding to 26 fewer per 1000 participants, 95% CI 62 fewer to 32 more). We rated the certainty of evidence as low for all these outcomes. Naftopidil likely reduced sexual adverse events (RR 0.15, 95% CI 0.06 to 0.42; corresponding to 126 fewer sexual adverse events per 1000 participants, 95% CI 139 fewer to 86 fewer). We rated the certainty of evidence as moderate for sexual adverse events.

AUTHORS' CONCLUSIONS

Naftopidil appears to have similar effects in the urological symptom scores and QoL compared to tamsulosin and silodosin. Naftopidil has similar sexual adverse events compared to tamsulosin but has fewer compared to silodosin.

New alpha blockers to treat male lower urinary tract symptoms

PURPOSE OF REVIEW

To date it is unclear whether the selectivity of new alpha-blockers to alpha-adrenergic receptor subtypes translates into more clinical benefits and less adverse effects in clinical practice. We performed a systematic review of the two new Abs silodosin and naftopidil. With the availability of numerous alpha-blockers to treat lower urinary tract symptoms secondary to benign prostatic hyperplasia, the findings of this review will be highly relevant to the field of urology.

RECENT FINDINGS

Silodosin was found to be more effective than placebo in improving International Prostate Symptom Score (IPSS) and quality of life scores and as effective as other alpha-blockers. Although the incidence of cardiovascular adverse events of silodosin was similar compared with placebo and other alpha-blockers (tamsulosin, naftopidil, alfuzosin), the sexual adverse events were more common with silodosin. No placebo-controlled randomized trial exists investigating the effects of naftopidil in men with lower urinary tract symptoms secondary to benign prostatic hyperplasia. Naftopidil had similar efficacy with regards to IPSS and quality of life compared with tamsulosin. The rate of adverse events was similar compared with tamsulosin.

SUMMARY

The two new selective alpha-blockers, silodosin, and naftopidil showed similar efficacy in IPSS and quality of life compared with other alpha-blockers. However, silodosin has more sexual adverse events.

Silodosin for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia

BACKGROUND

A variety of alpha-blockers are used for treating lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH). Silodosin is a novel, more selective alpha-blocker, which is specific to the lower urinary tract and may have fewer side effects than other alpha-blockers.

OBJECTIVES

To assess the effects of silodosin for the treatment of LUTS in men with BPH.

SEARCH METHODS

We performed a comprehensive search using multiple databases (Cochrane Library, MEDLINE, EMBASE, Scopus, Google Scholar, and Web of Science), trials registries, other sources of grey literature, and conference proceedings with no restrictions on the language of publication or publication status up until 13 June 2017.

SELECTION CRITERIA

We included all parallel, randomized controlled trials. We also included cross-over designs.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies and abstracted data from the included studies. We performed statistical analyses using a random-effects model and interpreted them according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of evidence according to the GRADE approach.

MAIN RESULTS

We included 19 unique studies with 4295 randomized participants across four comparisons for short-term follow-up. The mean age, prostate volume, and International Prostate Symptom Score were 66.5 years, 38.2 mL, and 19.1, respectively. Silodosin versus placeboBased on four studies with a total of 1968 randomized participants, silodosin may reduce urologic symptom scores in an appreciable number of men (mean difference (MD) -2.65, 95% confidence interval (CI) -3.23 to -2.08; low-quality evidence). Silodosin likely does not result in a clinically important reduction in quality of life (MD -0.42, 95% CI -0.71 to -0.13; moderate-quality evidence). It may not increase rates of treatment withdrawal for any reason (relative risk (RR) 1.08, 95% CI 0.70 to 1.66; low-quality evidence). We are uncertain about the effect of silodosin on cardiovascular adverse events (RR 1.28, 95% CI 0.67 to 2.45; very low-quality evidence). Silodosin likely increases sexual adverse events (RR 26.07, 95% CI 12.36 to 54.97; moderate-quality evidence); this would result in 180 more sexual adverse events per 1000 men (95% CI 82 more to 388 more). Silodosin versus tamsulosinBased on 13 studies with a total of 2129 randomized participants, silodosin may result in little to no difference in urologic symptom scores (MD -0.04, 95% CI -1.31 to 1.24; low-quality evidence) and quality of life (MD -0.15, 95% CI -0.53 to 0.22; low-quality evidence). We are uncertain about treatment withdrawals for any reason (RR 1.02, 95% CI 0.62 to 1.69; very low-quality evidence). Silodosin may result in little to no difference in cardiovascular adverse events (RR 0.77, 95% CI 0.53 to 1.12; low-quality evidence). Silodosin likely increases sexual adverse events (RR 6.05, 95% CI 3.55 to 10.31; moderate-quality evidence); this would result in 141 more sexual adverse events per 1000 men (95% CI 71 more to 261 more). Silodosin versus naftopidilBased on five studies with a total of 763 randomized participants, silodosin may result in little to no differences in urologic symptom scores (MD -0.85, 95% CI -2.57 to 0.87; low-quality evidence), quality of life (MD -0.17, 95% CI -0.60 to 0.27; low-quality evidence), treatment withdrawal for any reason (RR 1.25, 95% CI 0.81 to 1.93; low-quality evidence), and cardiovascular adverse events (RR 1.02, 95% CI 0.41 to 2.56; low-quality evidence). Silodosin likely increases sexual adverse events (RR 5.93, 95% CI 2.16 to 16.29; moderate-quality evidence); this would result in 74 more sexual adverse events per 1000 men (95% CI 17 more to 231 more). Silodosin versus alfuzosinBased on two studies with a total of 155 randomized participants, silodosin may or may not result in a clinically important increase in urologic symptom scores (MD 3.83, 95% CI 0.12 to 7.54; low-quality evidence). Silodosin likely results in little to no difference in quality of life (MD 0.14, 95% CI -0.46 to 0.74; moderate-quality evidence). We found no event of treatment withdrawal for any reason. Silodosin may not reduce cardiovascular adverse events (RR 0.67, 95% CI 0.36 to 1.24; low-quality evidence) but likely increases sexual adverse events (RR 37.21, 95% CI 5.32 to 260.07; moderate-quality evidence); this would result in 217 more sexual adverse events per 1000 men (95% CI 26 more to 1000 more).

AUTHORS' CONCLUSIONS

Silodosin may reduce urologic symptom scores in an appreciable number of men compared to placebo. Quality of life and treatment withdrawals for any reason appears similar. Its efficacy appears similar to that of other alpha blockers (tamsulosin, naftopidil and alfuzosin) but the rate of sexual side effects is likely higher. Our certainty in the estimates of effect was lowered due to study limitations, inconsistency and imprecision.

Systems pharmacology identifies drug targets for Stargardt disease-associated retinal degeneration

A systems pharmacological approach that capitalizes on the characterization of intracellular signaling networks can transform our understanding of human diseases and lead to therapy development. Here, we applied this strategy to identify pharmacological targets for the treatment of Stargardt disease, a severe juvenile form of macular degeneration. Diverse GPCRs have previously been implicated in neuronal cell survival, and crosstalk between GPCR signaling pathways represents an unexplored avenue for pharmacological intervention. We focused on this receptor family for potential therapeutic interventions in macular disease. Complete transcriptomes of mouse and human samples were analyzed to assess the expression of GPCRs in the retina. Focusing on adrenergic (AR) and serotonin (5-HT) receptors, we found that adrenoceptor α 2C (Adra2c) and serotonin receptor 2a (Htr2a) were the most highly expressed. Using a mouse model of Stargardt disease, we found that pharmacological interventions that targeted both GPCR signaling pathways and adenylate cyclases (ACs) improved photoreceptor cell survival, preserved photoreceptor function, and attenuated the accumulation of pathological fluorescent deposits in the retina. These findings demonstrate a strategy for the identification of new drug candidates and FDA-approved drugs for the treatment of monogenic and complex diseases.

The efficacy and safety of alpha-1 blockers for benign prostatic hyperplasia: an overview of 15 systematic reviews

OBJECTIVE

A great number of clinical trials and systematic reviews have evaluated the efficacy and safety of α(1) blockers for benign prostatic hyperplasia (BPH). We carried out an overview of reviews to provide an up-to-date summary of evidence regarding the efficacy and safety between different α(1) blockers for BPH.

RESEARCH DESIGN AND METHODS

PubMed, EMBASE, the Cochrane Library, China National Knowledge Infrastructure, Chinese BioMedical Literature Database and VIP were searched for eligible studies. Direct evidence was analyzed narratively. We used a random-effects model within a Bayesian framework to calculate indirect estimates if no direct evidence existed. The GRADE approach was used in summarizing conclusions.

RESULTS

A total of 15 systematic reviews involving five α(1) blockers met the inclusion criteria. Direct evidence demonstrated that α(1) blockers were superior to placebo in reducing urinary symptom scores and improving peak urinary flow PUF. Doxazosin could significantly reduce urinary symptom scores compared with tamsulosin mean difference (MD -1.60, 95% CI -1.80 to -1.40) and alfuzosin (MD1.7, 95% CI 0.76-1.64). Indirect evidence suggested that the urinary symptom score and PUF at endpoint in men treated with naftopidil were similar to those treated with other α(1) blockers. α(1) Blockers generally lead to more adverse effects compared with placebo, and those caused by terazosin were more frequent than others.

CONCLUSIONS

α(1) Blockers are more effective than placebo for BPH, doxazosin and tamsulosin seem to be more effective than other α(1) blockers. The adverse effects caused by α(1) blockers are generally mild and well-tolerated.

Orally applied doxazosin disturbed testosterone homeostasis and changed the transcriptional profile of steroidogenic machinery, cAMP/cGMP signalling and adrenergic receptors in Leydig cells of adult rats

Doxazosin (Doxa) is an α1-selective adrenergic receptor (ADR) antagonist widely used, alone or in combination, to treat high blood pressure, benign prostatic hyperplasia symptoms, and recently has been suggested as a potential drug for prostate cancer prevention/treatment. This study was designed to evaluate the effect of in vivo Doxa po-application, in clinically relevant dose, on: (i) steroidogenic machinery homeostasis; (ii) cAMP/cGMP signalling; (iii) transcription profile of ADR in Leydig cells of adult rats. The results showed that po-application of Doxa for once (1×Doxa), or for two (2×Doxa) or 10 (10×Doxa) consecutive days significantly disturbed steroidogenic machinery homeostasis in Leydig cells. Doxa po-application significantly decreased circulating luteinizing hormone and androgens levels. The level of androgens in testicular interstitial fluid and that extracted from testes obtained from 1×Doxa/2×Doxa rats decreased, although it remained unchanged in 10×Doxa rats. Similarly, the ex vivo basal androgen production followed in testes isolated from 1×Doxa/2×Doxa rats decreased, while remained unchanged in 10×Doxa rats. Differently, ex vivo testosterone production and steroidogenic capacity of Leydig cells isolated from 1×Doxa/2×Doxa rats was stimulated, while 10×Doxa had opposite effect. In the same cells, cAMP content/release showed similar stimulatory effect, but back to control level in Leydig cells of 10×Doxa. 1×Doxa/2×Doxa decreased transcripts for cAMP specific phosphodiesterases Pde7b/Pde8b, whereas 10×Doxa increased Pde4d. All types of treatment reduced the expression of genes encoding protein kinase A (PRKA) regulatory subunit (Prkar2b), whereas only 10×Doxa stimulated catalytic subunit (Prkaca). Doxa application more affected cGMP signalling: stimulated transcription of constitutive nitric oxide synthases (Nos1, Nos3) in time-dependent manner, whereas reduced inducible Nos2. 10×Doxa increased guanylyl cyclase 1 transcript and PRKG1 protein in Leydig cells. Orally applied Doxa significantly disturbed the transcriptional 'signature' of steroidogenic machinery, cAMP/cGMP signalling and ADRs and β-ADRs kinases in Leydig cells, thus giving new molecular insights into the role of cAMP/cGMP/adrenalin signalling in Leydig cells homeostasis.

Effects of electroacupuncture on benign prostate hyperplasia patients with lower urinary tract symptoms: a single-blinded, randomized controlled trial

We tested the effect of electroacupuncture (EA) on lower urinary tract symptoms (LUTS) in benign prostatic hyperplasia (BPH) patients. A total of 42 BPH patients with LUTS were randomly assigned to either the EA group (EG), received 2 Hz EA for 20 min twice/week for a total of twelve treatments, or a sham EA group (CG), received sham EA. The increase of voiding volume, average flow rate, and maximal flow rate in the EG were 32.2 ± 104.4 mL, 1.2 ± 1.6 mL/sec, and 2.3 ± 3.7 mL/sec, respectively, from baseline value (before EA) using the measurement of an uroflowmetry. These increases were greater than -37.9 ± 120.4, -0.22 ± 2.7, and -0.3 ± 4.3, respectively, in the CG (P = .038, .026, and .030, resp.). The changes of prostate special antigen and international prostatic symptom score were not significantly different between two groups (P = .573, .175, resp.), suggesting the clinical improvement of 2 Hz EA was quite limited to the LUTS of patients with BPH.