Safety and efficacy of doxazosin in benign prostatic hyperplasia: a pooled analysis of three double-blind, placebo-controlled studies

Safety and efficacy of an α1 -blocker plus mirabegron compared with an α1 -blocker plus antimuscarinic in men with lower urinary tract symptoms secondary to benign prostatic hyperplasia and overactive bladder: A systematic review and network meta-analysis

AIM

Antimuscarinics and the β3-adrenoreceptor agonist, mirabegron, are commonly used for treating patients with overactive bladder (OAB) and α1 -adrenoreceptor antagonists (α1 -blockers) are the main pharmacological agents used for treating lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). As these conditions commonly occur together, the aim of this systematic review was to identify publications that compared the use of an α1 -blocker plus mirabegron with an α1 -blocker plus antimuscarinic in men with LUTS secondary to BPH and OAB. A meta-analysis was subsequently conducted to explore the safety and efficacy of these combinations.

METHODS

Included records had to be from a parallel-group, randomized clinical trial that was ≥8 weeks in duration. Participants were male with LUTS secondary to BPH and OAB. The indirect analyses that were identified compared an α1 -blocker plus OAB agent with an α1 -blocker plus placebo. The PubMed/Medical Literature Analysis and Retrieval System Online, the Excerpta Medica Database, the Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov registry were searched for relevant records up until March 5, 2020. Safety outcomes included incidences of overall treatment-emergent adverse events (TEAEs) and urinary retention, postvoid residual volume, and maximum urinary flow (Qmax ). Primary efficacy outcomes were micturitions/day, incontinence episodes/day, and urgency episodes/day, and secondary outcomes were Overactive Bladder Symptom Score and International Prostate Symptom Score. A Bayesian network meta-analysis approach was used for the meta-analysis.

RESULTS

Out of a total of 1039 records identified, 24 were eligible for inclusion in the meta-analysis. There were no statistically significant differences between the α1 -blocker plus mirabegron and α1 -blocker plus antimuscarinic groups in terms of the comparisons identified for all the safety and efficacy analyses conducted. Numerically superior results were frequently observed for the α1 -blocker plus mirabegron group compared with the α1 -blocker plus antimuscarinic group for the safety parameters, including TEAEs, urinary retention, and Qmax . For some of the efficacy parameters, most notably micturitions/day, numerically superior results were noted for the α1 -blocker plus antimuscarinic group. Inconsistency in reporting and study variability were noted in the included records, which hindered data interpretation.

CONCLUSION

This systematic review and meta-analysis showed that an α1 -blocker plus mirabegron and an α1 -blocker plus antimuscarinic have similar safety and efficacy profiles in male patients with LUTS secondary to BPH and OAB. Patients may, therefore, benefit from the use of either combination within the clinical setting.

Clinical Efficacy of Serenoa repens Versus Placebo Versus Alpha-blockers for the Treatment of Lower Urinary Tract Symptoms/Benign Prostatic Enlargement: A Systematic Review and Network Meta-analysis of Randomized Placebo-controlled Clinical Trials

CONTEXT

International guidelines do not make any specific recommendations on Serenoa repens (SeR) for the treatment of male lower urinary tract symptoms (LUTS) secondary to benign prostatic enlargement (BPE), due to product heterogeneity and methodological limitations of the published trials and meta-analyses.

OBJECTIVE

We aimed to compare the clinical efficacy of hexanic extract of SeR (HESr) versus non-HESr (nHESr) versus placebo versus alpha-blockers (ABs) in patients affected by LUTS secondary to BPE through a network meta-analysis method.

EVIDENCE ACQUISITION

The search was conducted until December 31, 2018 using Medline, Scopus, and Web of Science databases without restriction. We included randomized controlled trials (RCTs) with at least one comparison between SeR, ABs, or placebo for the treatment of LUTS/BPE. Outcomes of the study were the mean change in the International Prostate Symptom Score (IPSS) and peak flow (PF). This systematic review has been registered on PROSPERO (CRD42018084360).

EVIDENCE SYNTHESIS

In total, 2115 articles were identified. After the global assessment, 22 RCTs matched with the inclusion criteria, including 8564 patients. For IPSS, the mean efficacies against placebo were +0.48 and -1.69 for HESr and nHESr, respectively, at 3 mo; 0.59 for nHESr at 6 mo; and -1.31 and -3.30 for nHESr and HESr, respectively, at 12 mo. For PF, the mean efficacies against placebo were +0.53 and +2.82 for HESr and nHESr, respectively, at 3 mo; +1.85 for nHESr at 6 mo; and +4.05 and +5.52 for HESr and nHESr, respectively, at 12 mo. Based on the surface under the cumulative ranking curve rankograms, terazosin showed the highest score (99.6%), while alfuzosin, tamsulosin, silodosin, HESr, and nHESr showed scores of 53.7%, 42.3%, 68.5%, 36.7%, and 47.3%, respectively.

CONCLUSIONS

In this network meta-analysis, we demonstrated that SeR did not show clinically meaningful improvement in LUTS and PF.

PATIENT SUMMARY

In the present study, we found no clinically meaningful improvement of Serenoa repens for the treatment of lower urinary tract symptoms/benign prostatic enlargement. The analysis showed that the benefit over placebo was minimal and may not justify its clinical use before higher level of evidence will be available.

Lactogenic hormones regulate mammary protein synthesis in bovine mammary epithelial cells via the mTOR and JAK–STAT signal pathways

The expression of CSN3, hormone receptor, the expression of genes regulating the mTOR, JAK–STAT signal pathways, and the relative content of к-casein as well as total casein were determined in the present study to explore the mechanism of the effect of lactogenic hormones on milk-protein synthesis in bovine mammary epithelial cells. The results showed that apoptosis of the cells was increased by inhibitor LY294002, while the expressions of genes encoding PKB, Rheb, PRAS40 and S6K1 in the mTOR signal pathway, JAK2, STAT5A in the JAK–STAT signal pathway, and genes encoding INSR, PRLR, NR3C1 and CSN3 were all downregulated, and the relative contents of κ-casein and total casein were decreased in the mammary epithelial cells compared with those in the control group. Comparatively, the inhibitory effects of AG-490 were more profound than those of LY294002, and the double block using both inhibitors had a greater effect than the single block. The CSN3 gene expression was downregulated and the content of milk casein was decreased by the inhibitors. In addition, the expression of the hormone receptor genes was downregulated. Our results suggest that lactogenic hormones, via their receptors in the membrane, regulated the JAK–STAT and m-TOR signal pathways, and affected cell proliferation and apoptosis, leading to changes in milk-protein synthesis.

Comparative effectiveness of oral drug therapies for lower urinary tract symptoms due to benign prostatic hyperplasia: a systematic review and network meta-analysis

INTRODUCTION

Lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) are common in elder men and a number of drugs alone or combined are clinically used for this disorder. But available studies investigating the comparative effects of different drug therapies are limited. This study was aimed to compare the efficacy of different drug therapies for LUTS/BPH with network meta-analysis.

MATERIALS AND METHODS

An electronic search of PubMed, Cochrane Library and Embase was performed to identify randomized controlled trials (RCTs) comparing different drug therapies for LUTS/BPH within 24 weeks. Comparative effects were calculated using Aggregate Data Drug Information System. Consistency models of network meta-analysis were created and cumulative probability was used to rank different therapies.

RESULTS

A total 66 RCTs covering seven different therapies with 29384 participants were included. We found that α-blockers (ABs) plus phosphodiesterase 5 inhibitors (PDE5-Is) ranked highest in the test of IPSS total score, storage subscore and voiding subscore. The combination therapy of ABs plus 5α-reductase inhibitors was the best for increasing maximum urinary flow rate (Qmax) with a mean difference (MD) of 1.98 (95% CI, 1.12 to 2.86) as compared to placebo. ABs plus muscarinic receptor antagonists (MRAs) ranked secondly on the reduction of IPSS storage subscore, although monotherapies including MRAs showed no effect on this aspect. Additionally, PDE5-Is alone showed great effectiveness for LUTS/BPH except Qmax.

CONCLUSIONS

Based on our novel findings, combination therapy, especially ABs plus PDE5-Is, is recommended for short-term treatment for LUTS/BPH. There was also evidence that PDE5-Is used alone was efficacious except on Qmax. Additionally, it should be cautious when using MRAs. However, further clinical studies are required for longer duration which considers more treatment outcomes such as disease progression, as well as basic research investigating mechanisms involving PDE5-Is and other pharmacologic agents alleviate the symptoms of LUTS/BPH.

Current role of treatment in men with lower urinary tract symptoms combined with overactive bladder

Lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia (BPH) are highly prevalent in older men. The storage subcategory of LUTS is synonymous with overactive bladder (OAB) syndrome, which is an empirical diagnosis. Traditionally, alpha-blockers are widely prescribed to manage the LUTS of BPH, although storage symptoms may persist in many men despite treatment. Therefore, because therapies that target the prostate often fail to alleviate storage symptoms, they may not be the appropriate therapy for OAB. In past years, most physicians appeared to give more weight in elderly men to voiding symptoms than to storage symptoms and to be more concerned with initial treatment with anticholinergics for males with storage symptoms. Considering the recent increase in data on the efficacy and safety of combination treatment with alpha receptor antagonists and antimuscarinic agents, the standard pharmacologic treatment of patients with LUTS combined with OAB should be an alpha receptor antagonist and an antimuscarinic agent. Beta-3 adrenoreceptor agonists may also potentially be useful for the treatment of male LUTS combined with OAB.

In Vitro-In Vivo Correlation Evaluation of Generic Alfuzosin Modified Release Tablets

Alfuzosin, a selective alpha-1a antagonistis is the most recently approved AARAS, with limited cardiac toxicity and exclusively used for lower urinary tract syndromes (LUTS). In order to reduce pill burden and better patient compliance modified release (MR) formulations have been developed. Alfuzosin MR tablet was developed by the use of hot-melt granulation techniques using mono- and diglycerides as rate controlling membranes to minimize health care cost and uses of costly excipients. The other purpose of the study was to evaluate in vitro-in vivo performance of the scale up batch in healthy human subjects for commercialization. The blend uniformity (mean ± RSD%), assay, cumulative percent dissolution at 24 h, hardness, and friability of the biobatch were 100.2 ± 0.05%, 100.43 ± 0.023%, 93.98%, 4.5 kg, 5 min, and 0.08%, respectively. The in vivo pharmacokinetic parameters under fasting conditions between test and reference formulations (Uroxatral 10 mg extended release tablets) were comparable. The 90% CI, geometric mean ratio (%) and power of C_max, AUCT, and AUCI of the fasting study for the test and reference formulation were 99.03% to 122.78%, 109%, 0.998; 92.94% to 116.71%, 104%, 1; 98.17% to 124.01%, 110% 1, respectively. The scale up biobatch showed negligible difference in in vitro properties with respect to the pilot batch. The formulation developed with these agents was safe to use as there were no serious adverse events developed during the conduction of the clinical trial on the healthy subjects. Furthermore, the developed formulation was bioequivalent with respect to rate and extends of absorption to the reference formulation.

Efficacy of Dose Escalation of Tamsulosin for the Treatment of Lower Urinary Tract Symptoms

OBJECTIVES

The aim of this study was to compare the efficacy of low (0.2 mg) and intermediate (0.4 mg) dose tamsulosin in treating lower urinary tract symptoms (LUTS).

METHODS

Patients were treated with low-dose tamsulosin for an initial run-in period of 12 weeks, then divided into two groups based on their clinical improvement. Patients were measured for objective parameters of peak flow rate and postvoid residual urine volume, as well as subjective symptom scores and perceived patient benefit of treatment. The items were then integrated as the LUTS Outcome Score to determine dose increase or maintenance. Overall outcome was determined at 36 weeks.

RESULTS

One hundred and seventy-four patients were enrolled and started on 0.2 mg tamsulosin treatment. One hundred and fifty-five patients completed the 36-week study. Sixty patients required dose increase to 0.4 mg at the 12th week. Baseline characteristics showed that a patient who would benefit from 0.4 mg dosage had higher age, daytime frequency, and lower peak urine flow rate. Patients receiving both 0.2 and 0.04 mg both showed improved clinical outcome measures. Higher improvement was found in voiding component symptom scores and urine flow rate improvement in patients receiving an increased dose.

CONCLUSION

Both low- and intermediate-dose tamsulosin are effective treatment regimens. Increasing from low to intermediate dose should follow assessment of both objective and subjective improvements.

Tamsulosin oral controlled absorption system (OCAS) in the treatment of benign prostatic hypertrophy

The efficacy of tamsulosin at the cost of a relatively benign side effect profile has been attributed to receptor selectivity directed at the α_1a and α_1d adrenergic receptor subtypes. The oral-controlled absorption system (OCAS^®) represents a drug delivery refinement that incorporates a matrix of gel-forming and gel-enhancing agents to promote a constant drug release independent of environmental food or fluid. There are clinical data to support the concept that drug peaks are lessened and that drug release continues throughout the alimentary tract due to the OCAS formulation. Furthermore this equates with less adverse effects on physiologic parameters. To date however improvements in cardiovascular symptoms such as dizziness, headache and syncope have not been demonstrated in healthy men. Ejaculatory dysfunction appears less problematic with the OCAS preparation. Tamsulosin OCAS may be of greatest benefit to men with cardiovascular co-morbidities taking anti-hypertensive medications that might predispose them to symptomatic hypotensive episodes. It will be necessary to evaluate this group of men more closely in further trials to determine what they stand to gain from changing medications, and then relate this to drug costs to draw a final conclusion as to the place of tamsulosin OCAS in contemporary urological practice.

Measurement of benign prostatic hyperplasia treatment effects on male sexual function

Benign prostatic hyperplasia (BPH) is the leading cause of lower urinary tract symptoms among the aging male population. Epidemiological, pathophysiological and clinical studies indicate that many of these men also suffer from declining sexual function, especially those undergoing treatment for their BPH-related urinary symptoms. Although urinary symptoms and quality of life may improve with BPH therapy, the resulting effects on sexual function vary by medical, surgical and minimally invasive approaches and have not been consistently reported. As comprehensive, validated instruments to measure male sexual function are now available for routine use in the clinical setting, urologists and primary care providers caring for patients with BPH have the opportunity to monitor both urinary and sexual function before, during and after BPH therapy. Herein, we describe the relationship between BPH and its treatments on male sexual function, the role of new measures for sexual functioning and opportunities for future work to improve the care of men suffering from both maladies.

Double-blind randomized placebo-controlled study of Bixa orellana in patients with lower urinary tract symptoms associated to benign prostatic hyperplasia

OBJECTIVE

To determine the efficacy of Bixa Orellana (BO) in patients with benign prostatic hyperplasia (BPH) presenting moderate lower urinary tract symptoms (LUTS).

MATERIALS AND METHODS

It is a prospective double-blind randomized placebo-controlled study. One thousand four hundred and seventy eight patients presenting moderate LUTS associated to BPH were interviewed, from whom we selected 136 to fulfill the criteria of inclusion and exclusion. Assignation was performed at random in blocks of four to receive B0 at a dose of 250 mg 3 times a day or placebo (Pbo) for 12 months, 68 patients were assigned to each group. From the patients in the study we obtained data of demographic, epidemiologic, symptom score, uroflowmetry and post void residual urine variables.

RESULTS

Basically both groups were compared clinically, demographically and biochemically. Throughout the study variations of symptom score, mean delta symptom score during each visit and the final average delta were similar for both groups (BO - 0.79 +/- 1.87 and Pbo - 1.07 +/- 1.49) (p = 0.33). Similarly variations of Qmax mean, Qmax average delta and final average delta were similar (BO 0.44 +/- 1.07 and Pbo 0.47 +/- 1.32) (p = 0.88). Variations of post void residual urine mean, post void residual urine average delta in each visit and the final average delta were similar for both groups (BO 4.24 +/- 11.69 and Pbo 9.01 +/- 18.66) (p = 0.07). No differences were found in the answers of clinically significant improvement assessed with relative risk and risk differences, even though the proportion of adverse effects was similar for both groups.

CONCLUSION

Patients with BPH that present moderate LUTS did not show any benefit receiving BO when compared to placebo.

Alpha1 Adrenoceptors in Human Urinary Tract: Expression, Distribution and Clinical Implications

Adrenergic receptors (ARs) are a class of proteins belonging to the G protein-coupled receptor family. Pharmacological and molecular studies allowed dividing ARs into three different categories: α1, α2 and β. In this review, we focused on α1 ARs and α1 AR antagonists, since α 1 ARs play an important role in the pathophysiology of a number of urinary tract (UT) dysfunctions. α1 ARs are widely expressed in human UT; in particular, the three ureter areas (distal, medial and proximal) show different patterns of receptor expression (i.e. distal > medial = proximal), giving the molecular basis for the use of α1 ARs antagonist in the expulsive therapy of distal ureter calculi. Bladder areas are characterized by important differences among trigone, detrusor and neck, the first showing a different pattern of expression compared to the other parts. Further, there are evidences of both density and subtype gender-dependent expressions. α1 ARs expression in prostate and detrusor is a widely investigated area of research, mainly due to the clinical impact of benign prostatic hyperplasia (BPH). Urethra has not been well studied in human, although it plays a role in the control of continence.

Studies carried out on α1 AR subtype expression in the UT indicate that, although the presence of each subtype is observed, α1A firstly and then α1D ARs seem to be more expressed than α1B ARs. Thus, drugs that demonstrate high α1A/D AR selectivity have drawn the researchers’ attention. As it relates specifically to the α1 AR antagonists used in the treatment of lower UT symptoms, the concept of uroselectivity has been operationally defined; indeed, in a number of recent publications uroselectivity has been defined as the degree to which a given compound inhibits norepinephrine-induced increase in urinary muscle contractions and/or its propensity to generate unwanted cardiovascular effects, such as decreases in blood pressure.

Medical treatment of benign prostatic hyperplasia

Pharmaceutical preparations are commonly used for benign prostate hyperplasia. This article reviews the current understanding of the natural history of the condition and the literature regarding medical treatment.

A novel approach to the treatment of benign prostatic hyperplasia

OBJECTIVE

To assess the clinical efficacy and safety of the combined alpha1- and postsynaptic alpha2-blocker GYKI-16084 compared to placebo during a 28-day active treatment of patients with benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

After a 28-day placebo run-in phase, 7.5 and 15 mg GYKI-16084 or placebo were administered twice daily for 28 days to patients with BPH in a randomized single-blind Phase II study. Efficacy was primarily determined by changes in the American Urological Association (AUA) symptom scores and maximum urinary flow (Q(max)), while safety was assessed by orthostatic changes and adverse-event profile. A simplified International Index of Erectile Function questionnaire was used to assess effects on erectile function.

RESULTS

Data from 63 patients were evaluated; the decrease in the AUA score during the active phase was greater in the 15 mg group (-6.05, -32.7%) than in the placebo (-4.3, 22.7%) or 7.5 mg (-3.55, -19.5%) groups. Q(max) improved in both active treatment groups (+3.3 and +2.16 mL for the 7.5 and 15 mg groups, respectively) compared to placebo (+1.29 mL). None of the drug-related adverse events associated with selective alpha1-blockers were reported.

CONCLUSION

The combined alpha1- and postsynaptically selective alpha2-blocker GYKI-16084 significantly improved the AUA symptom scores and increased Q(max) in patients with BPH, without inducing any adverse reaction, orthostatic changes or erectile dysfunction.

Saw palmetto for benign prostatic hyperplasia

BACKGROUND

Saw palmetto is used by over 2 million men in the United States for the treatment of benign prostatic hyperplasia and is commonly recommended as an alternative to drugs approved by the Food and Drug Administration.

METHODS

In this double-blind trial, we randomly assigned 225 men over the age of 49 years who had moderate-to-severe symptoms of benign prostatic hyperplasia to one year of treatment with saw palmetto extract (160 mg twice a day) or placebo. The primary outcome measures were changes in the scores on the American Urological Association Symptom Index (AUASI) and the maximal urinary flow rate. Secondary outcome measures included changes in prostate size, residual urinary volume after voiding, quality of life, laboratory values, and the rate of reported adverse effects.

RESULTS

There was no significant difference between the saw palmetto and placebo groups in the change in AUASI scores (mean difference, 0.04 point; 95 percent confidence interval, -0.93 to 1.01), maximal urinary flow rate (mean difference, 0.43 ml per minute; 95 percent confidence interval, -0.52 to 1.38), prostate size, residual volume after voiding, quality of life, or serum prostate-specific antigen levels during the one-year study. The incidence of side effects was similar in the two groups.

CONCLUSIONS

In this study, saw palmetto did not improve symptoms or objective measures of benign prostatic hyperplasia. (ClinicalTrials.gov number, NCT00037154.).

Doxazosin in the treatment of benign prostatic hypertrophy: an update

We evaluated the efficacy and safety of alpha 1--blocker doxazosin for treatment of lower urinary tract symptoms (LUTS) compatible with benign prostatic hypertrophy (BPH). Fourteen randomized controlled trials enrolled 6261 men, average age 64 years, who had moderately severe LUTS and flow impairment. Compared with baseline measures and placebo effect, doxazosin resulted in a statistically significant improvement in both LUTS and flow. However, when compared with placebo, the average magnitude of symptom improvement (International Prostate Symptom Score [IPSS] improvement < 3 points) typically did not achieve a level detectable by patients. Combined doxazosin and finasteride therapy improved LUTS and reduced the risk of overall clinical progression of BPH compared to each drug separately in men followed over 4 years. Reported mean changes from baseline in the IPSS were -7.4, -6.6, -5.6, and -4.9 points for combination therapy, doxazosin, finasteride, and placebo, respectively. Combination therapy reduced the need for invasive treatment for BPH and the risk of long-term urinary retention. The absolute reductions compared with placebo were less than 4% and primarily seen in men with prostate gland volume > 40 mL or PSA levels > 4 ng/mL. Efficacy was comparable with other alpha 1--blockers. Withdrawals from treatment for any cause were comparable to placebo. Dizziness and fatigue occurred more frequently with doxazosin compared to placebo.

Lower urinary tract symptoms suggestive of benign prostatic hyperplasia: latest update on alpha-adrenoceptor antagonists

An update of a systematic review of alpha1-adrenoceptor (AR) antagonists in the treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) showed that these agents have comparable efficacy. The total symptom score is improved by 30-45% and maximum urinary flow rate by 15-30% vs baseline. alpha1-AR antagonists that can be started at their therapeutic dose have a more rapid onset of action than alpha1-AR antagonists that have to be titrated. alpha1-AR antagonists can be differentiated according to their tolerability. Alfuzosin (especially the 10 mg once daily dose) and tamsulosin (especially the 0.4 mg once daily dose) are better tolerated than doxazosin and terazosin. However, alfuzosin might induce more cardiovascular adverse events (AEs) in the elderly and/or patients with cardiovascular comorbidity and/or comedication. Tamsulosin tends to interfere less with blood pressure regulation and induce less vasodilatory AEs than alfuzosin, especially in the elderly, and is well tolerated in patients with cardiovascular comorbidity and/or comedication. Cardiovascular AEs might lead to potentially serious complications such as falls, fractures and institutionalization. Abnormal ejaculation has mainly been reported in placebo-controlled trials with tamsulosin but in direct comparative trials its rate with tamsulosin 0.4 mg was similar to, or only slightly higher than, the rate with alfuzosin. In addition, abnormal ejaculation is not reported as bothersome by the patient or associated with serious complications. It can be concluded that an alpha1-AR antagonist with a low potential to interfere with blood pressure regulation and to induce cardiovascular AEs, also in patients with cardiovascular comorbidity and/or comedication, can be considered a first-choice treatment option in LUTS/BPH.

After ALLHAT: doxazosin for the treatment of benign prostatic hyperplasia

Doxazosin mesylate is an alpha1-adrenoceptor antagonist that was used to treat hypertension until a major study (ALLHAT; Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial) showed that it increased the risk of progressing to heart failure. Doxazosin is now being used to treat benign prostatic hyperplasia (BPH). Noradrenaline acts on alpha1-adrenoceptors to contract the smooth muscle in the prostate and bladder, and by opposing these actions, doxazosin is beneficial in BPH. Doxazosin also increases apoptosis in the prostate. Although the standard preparation is suitable for once-daily dosing in BPH, it has to be titrated through three steps to its final dose. The controlled-release gastrointestinal therapeutic system (GITS) formulation of doxazosin is more convenient to use as it only has to be titrated through one step. In the treatment of BPH, standard doxazosin reduced both obstructive and irritative symptoms and increased peak urinary flow rate. The main side effects with doxazosin are those commonly associated with lowering blood pressure, although doxazosin lowers blood pressure to a lesser extent in normotensives than hypertensives. There is some evidence that in addition to being easier to use, doxazosin GITS may cause less adverse effects than the standard preparations. The benefits of doxazosin and the 5alpha-reductase inhibitor, finasteride, may be additive in BPH especially in men with large prostates. Further trials are necessary in order to determine whether doxazosin GITS is superior to other alpha1-adrenoceptor antagonists in BPH.

Doxazosin for treating lower urinary tract symptoms compatible with benign prostatic obstruction: a systematic review of efficacy and adverse effects

OBJECTIVE

To evaluate the efficacy and adverse effects of doxazosin for treating lower urinary tract symptoms (LUTS) compatible with benign prostatic obstruction (BPO).

METHODS

Randomized controlled trials were included in the meta-analysis if: the study duration was > or = 1 month; the study involved men with symptomatic BPO; and doxazosin was compared with placebo or active controls. Study and patient characteristics and outcome data were extracted in duplicate onto standardized forms using a prospectively developed protocol.

RESULTS

Thirteen studies involving 6033 men with (mean age 64 years) met the inclusion criteria; 10 were placebo-controlled, including two with combined doxazosin/finasteride therapy and finasteride monotherapy arms. Three trials were a comparison with other alpha-blockers. The study duration was 1-54 months. The mean baseline symptom scores and peak urinary flow (PUF) rates were indicative of moderate BPO. Doxazosin gave significant improvements in LUTS, assessed by symptom scores, vs placebo and finasteride in the short- to long-term. Two long-term studies (1 and 4 years) reported mean changes from baseline for the International Prostate Symptom Score of - 8.3 and - 6.6 points (-49% and - 39%) for doxazosin and - 5.7 and - 4.9 points (-33% and - 29%) for placebo, respectively. Doxazosin significantly increased PUF rates vs placebo. In pooled results from three studies, the weighted mean difference in the mean change from baseline vs placebo was 1.6 mL/s (95% confidence interval 1.2-2.1). Efficacy was comparable with other alpha1-blockers. In the long-term (>4 years) doxazosin was no better then finasteride in improving PUF. Combined doxazosin and finasteride significantly reduced the risk of overall clinical progression of BPO vs each drug separately in men followed for >4 years. Absolute risk reductions vs placebo were 11.3%, 6.9% and 6.4% for combined therapy, doxazosin and finasteride, respectively (P < 0.001). Improvements in symptom scores and PUF were also significantly greater with combined than monotherapy, and the former reduced the need for invasive treatment for BPO and the risk of long-term urinary retention, although the absolute reductions in risk vs placebo were small (<4%). Dizziness and fatigue were significantly more common with doxazosin than placebo (11% vs 7%, and 6% vs 3%, respectively). Adverse events reported for combined therapy were similar to those with each monotherapy.

CONCLUSION

The evidence indicates that doxazosin is effective and generally well tolerated for improving LUTS and PUF in men with symptomatic BPO. Combined therapy was better than doxazosin alone in reducing the risk of clinical progression of BPO and other long-term complications related to BPO.

Doxazosin for benign prostatic hyperplasia: An open-label, baseline-controlled study in Korean general practice

BACKGROUND

Few studies have reported the treatment of benign prostatic hyperplasia (BPH) in Asian patients. We assessed the safety and efficacy of doxazosin, a selective alpha1-adrenoceptor antagonist, in the treatment of Korean patients with symptomatic BPH.

METHODS

Two hundred and ninety-five men, aged 48 years or older with clinical BPH, were enrolled in a 12-week, open-label, baseline-controlled, dose-titration, multicenter study. A 2-week, single-blind, placebo run-in was followed by 10 weeks of doxazosin treatment, initially administered at 1 mg/day, with upward titrations (2, 4, or 8 mg/day) at 2-week intervals. The international prostate symptom score (IPSS) was used to assess efficacy after 4, 6, and 10 weeks of active treatment.

RESULTS

The intent-to-treat (ITT) population comprised 249 patients (mean age 63.6 years). Doxazosin significantly reduced the mean total IPSS by 48%; similarly, the obstructive and irritative subscores were reduced from baseline by 51% and 39%, respectively (P < 0.001 for all scores: Wilcoxon rank sum test). In a subset analysis of 170 normotensive and 78 hypertensive patients, significant reductions in mean systolic and diastolic blood pressures relative to baseline were observed only in the hypertensive subset (P < 0.01). Similar results in mean IPSS were observed in older (> or =65 years, n = 100) and younger (45-64 years, n = 140) patients, as well as between normotensive and hypertensive patients. Thirty-nine patients reported adverse events: The most frequent were dizziness, dyspepsia, asthenia, somnolence, and dry mouth.

CONCLUSIONS

The efficacy and safety of doxazosin treatment for BPH were confirmed in this Asian population. Significant improvements in total IPSS, as well as obstructive and irritative subscores, were observed.

Comparative efficacy of two alpha-adrenoreceptor antagonists, doxazosin and alfuzosin, in patients with lower urinary tract symptoms from benign prostatic enlargement

OBJECTIVES

To compare doxazosin and alfuzosin in patients with moderate to severe lower urinary tract symptoms (LUTS) suggestive of bladder outlet obstruction.

PATIENTS AND METHODS

In all, 210 men with LUTS were randomized to receive doxazosin 1-8 mg once daily or alfuzosin 5-10 mg divided in two or three daily doses in a 14-week, multicentre, double-blind, baseline-controlled, dose-titration study. The International Prostate Symptom Score (IPSS) and maximum urinary flow rate were used to assess the efficacy of the treatment.

RESULTS

At study completion, the mean dose of doxazosin was 6.1 mg/day and alfuzosin 8.8 mg/day. The least squares mean (se) change from baseline in total IPSS was -9.23 (0.6) for doxazosin and -7.45 (0.6) (both P < 0.001) for alfuzosin. The respective mean change from baseline in irritative symptoms was -3.5 (0.2) and -2.8 (0.3) (both P < 0.001). The differences between the treatment groups were statistically significant in favour of doxazosin (total IPSS, P = 0.036; irritative symptoms, P = 0.049). The improvement between groups was also significantly different for postvoid residual urine volume, at -29.19 (8.6) and + 9.59 (8.9) mL for doxazosin and alfuzosin, respectively (P = 0.002). Improvements in mean and maximum urinary flow rates were similar for both treatments, at + 1.5 and + 1.2, and + 2.8 and + 2.5 mL/s, respectively. Doxazosin and alfuzosin were both well tolerated, with most all-cause adverse events reported as mild or moderate.

CONCLUSIONS

The mean doses of doxazosin and alfuzosin used in this study were not equipotent. Doxazosin 6.1 mg/day produced significantly greater improvements than alfuzosin 8.8 mg/day in total and irritative urinary symptom scores and postvoid residual urine volume in men with moderate to severe LUTS. Changes in maximum and mean flow rates were comparable. Doxazosin and alfuzosin were both well tolerated.

α1-Adrenergic Receptors and Their Inhibitors in Lower Urinary Tract Symptoms and Benign Prostatic Hyperplasia

PURPOSE

We provide a comprehensive overview of the role of alpha1-adrenergic receptors (alpha1ARs) as critical mediators of lower urinary tract symptoms (LUTS) and pathophysiology in benign prostatic hyperplasia (BPH), and we review the pharmacological antagonists of alpha1ARs.

MATERIALS AND METHODS

A review was performed of pertinent studies in the literature relating to the pathophysiology of LUTS and BPH, focusing on the role of alpha1ARs, and of clinical trial and practice data evaluating the different agents that inhibit these receptors.

RESULTS

Further characterization of the alpha1AR gene family indicates that 3 receptor subtypes exist in humans. Their different distribution between urinary tract and cardiovascular tissues has provided a strategy for the development of improved therapeutic agents. Since excessive activity of the alpha1aAR and alpha1dAR subtypes appears to be a common feature in symptomatic BPH and alpha1aARs are enriched in prostatic tissue, drugs that demonstrate high alpha1aAR selectivity have attracted attention. Tamsulosin, which has high affinity for alpha1aAR and alpha1dAR subtypes but not for alpha1bAR, shows efficacy similar to the nonsubtype selective agents terazosin and doxazosin. It is associated with fewer cardiovascular side effects, although it has some ejaculatory side effects. The nonsubtype selective agent alfuzosin also demonstrates efficacy and offers an enhanced side effect profile, particularly minimizing hypotension. Other agents with super selective specificity for the alpha1aAR subtype are under investigation.

CONCLUSIONS

Further advances in the treatment of LUTS associated with BPH may depend not only on receptor subtype selectivity, but also on other pharmacokinetic and pharmacodynamic factors.

Drug treatments for lower urinary tract symptoms secondary to bladder outflow obstruction: focus on quality of life

Benign prostatic hyperplasia (BPH), now referred to as lower urinary tract symptoms suggestive of bladder outflow obstruction (LUTS/BOO), is a significant cause of morbidity in ageing men. Surgery has virtually eliminated BPH-related mortality, and so the focus for men and their urologist is improvement in urinary symptoms and quality of life. Numerous tools have been developed to quantify symptoms and impact on quality of life--the most commonly used is the International Prostate Symptom Score. Sexual function and the avoidance of BPH-related complications such as acute urinary retention and surgery are also important to men--tools are available to assess sexual function but the benefits of complication avoidance are difficult to quantify. Approximately one million men in the UK have brought their symptoms to the attention of their doctor and been given a diagnosis of BPH, but extrapolation from community based studies suggests that many more (up to 2.5 million men) may have significant symptoms without seeking attention. Histopathological BPH, diminishing peak urinary flow rate, worsening lower urinary tract symptoms and increasing impact on quality of life all become more common as men age. Two groups of drugs are commonly used to treat LUTS/BOO--alpha-adrenoreceptor antagonists and 5alpha-reductase inhibitors. Both groups have been shown to improve quality of life measures in randomised, placebo-controlled trials--usually by approximately twice as much as placebo.

The long-term effect of doxazosin, finasteride, and combination therapy on the clinical progression of benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia is commonly treated with alpha-adrenergic-receptor antagonists (alpha-blockers) or 5alpha-reductase inhibitors. The long-term effect of these drugs, singly or combined, on the risk of clinical progression is unknown.

METHODS

We conducted a long-term, double-blind trial (mean follow-up, 4.5 years) involving 3047 men to compare the effects of placebo, doxazosin, finasteride, and combination therapy on measures of the clinical progression of benign prostatic hyperplasia.

RESULTS

The risk of overall clinical progression--defined as an increase above base line of at least 4 points in the American Urological Association symptom score, acute urinary retention, urinary incontinence, renal insufficiency, or recurrent urinary tract infection--was significantly reduced by doxazosin (39 percent risk reduction, P<0.001) and finasteride (34 percent risk reduction, P=0.002), as compared with placebo. The reduction in risk associated with combination therapy (66 percent for the comparison with placebo, P<0.001) was significantly greater than that associated with doxazosin (P<0.001) or finasteride (P<0.001) alone. The risks of acute urinary retention and the need for invasive therapy were significantly reduced by combination therapy (P<0.001) and finasteride (P<0.001) but not by doxazosin. Doxazosin (P<0.001), finasteride (P=0.001), and combination therapy (P<0.001) each resulted in significant improvement in symptom scores, with combination therapy being superior to both doxazosin (P=0.006) and finasteride (P<0.001) alone.

CONCLUSIONS

Long-term combination therapy with doxazosin and finasteride was safe and reduced the risk of overall clinical progression of benign prostatic hyperplasia significantly more than did treatment with either drug alone. Combination therapy and finasteride alone reduced the long-term risk of acute urinary retention and the need for invasive therapy.

Lower urinary tract symptoms/benign prostatic hyperplasia: minimizing morbidity caused by treatment

The beneficial effects of treatment for lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH), or LUTS/BPH, have to be balanced against the morbidity associated with treatment. Invasive surgery, such as transurethral resection of the prostate, has been associated with irreversible complications (eg, impotence and retrograde ejaculation). Alpha(1)-adrenoceptor antagonists provide effective and fast relief of LUTS/BPH. In contrast to finasteride, they are not associated with sexual dysfunction (eg, decreased libido or impotence). Alpha(1)-adrenoceptor antagonists induce adverse events associated with interference with blood pressure regulation. The alpha(1A)/alpha(1D)-adrenoceptor antagonist tamsulosin has the lowest potential to interfere with blood pressure regulation and induce related adverse events. In addition, tamsulosin seems to be as well tolerated as phytotherapy, except for a higher incidence of abnormal ejaculation. Abnormal ejaculation occurs in 4% to 11% of patients receiving a alpha(1)-adrenoceptor antagonist, which is, however, well tolerated; <1% of patients discontinue because of this adverse event. In placebo-controlled trials, abnormal ejaculation has been predominantly reported for tamsulosin, but in most direct comparative studies, the incidence was comparable to that of other alpha(1)-adrenoceptor antagonists. Men with LUTS/BPH have an increased risk of impaired sexual function. However, alpha(1)-adrenoceptor antagonists, such as tamsulosin, may slightly improve sexual dysfunction together with LUTS problems. Combination therapy of an alpha(1)-adrenoceptor antagonist and finasteride has a similar adverse-event profile as each monotherapy, except for an increased risk of abnormal ejaculation. The discontinuation rate because of adverse events does not seem to be higher than with monotherapy. Medical therapies, and particularly alpha(1)-adrenoceptor antagonists such as tamsulosin, can be considered a first-line treatment option for LUTS/BPH because they provide effective relief of bothersome LUTS with excellent tolerability.

Safety and efficacy of alfuzosin 10 mg once-daily in the treatment of lower urinary tract symptoms and clinical benign prostatic hyperplasia: a pooled analysis of three double-blind, placebo-controlled studies

OBJECTIVES

To examine the efficacy and safety of a once-daily formulation of alfuzosin in a pooled analysis of three parallel, randomized, double-blind, placebo-controlled 3-month studies of patients with lower urinary tract symptoms (LUTS) consistent with clinical benign prostatic hyperplasia.

PATIENTS AND METHODS

Patients were randomized to receive alfuzosin, 10 mg once-daily (473) or placebo (482) for 12 weeks. Primary efficacy criteria were improvements in the International Prostate Symptom Score (IPSS) and peak urinary flow rate (PFR).

RESULTS

Alfuzosin significantly improved the mean (sd) IPSS, by - 6.0 (5.1) vs - 4.2 (5.7) with placebo (P < 0.005) and the PFR, by + 2.3 (3.8) vs + 1.1 (3.1) ml/s with placebo (P < 0.001), irrespective of prostate size. The significant improvement in LUTS included the irritative and the obstructive subscore of the IPSS and the nocturia criterion; the PFR increased rapidly and significantly, from the first visit (14 days). The quality-of-life score also improved significantly in alfuzosin-treated patients. Alfuzosin was well tolerated; the number of withdrawals for adverse events was comparable in both treatment groups. The most frequently reported adverse event was dizziness (placebo 2.9%, alfuzosin 6.1%). There were no significant changes in blood pressure with alfuzosin compared with placebo, including in elderly and hypertensive patients. Sexual adverse events were rare (abnormal ejaculation, 0.6%).

CONCLUSIONS

The once-daily formulation of alfuzosin, administered at 10 mg with no dose titration is effective, with a good safety profile, especially in elderly and hypertensive patients.

Medical therapy for benign prostatic hyperplasia: sexual dysfunction and impact on quality of life

Therapies for benign prostatic hyperplasia (BPH) may either improve or exacerbate sexual function with an ensuing impact on quality of life. Here we review a total of 73 papers on medical therapies for BPH with a focus on the effects of different pharmacological agents on sexual function. For example, certain alpha(1)-adrenergic receptor blockers may improve erectile function; however, ejaculatory dysfunction with one of these agents, tamsulosin, occurs at a rate of 4-18%, rising to 30% with long-term use. In addition, treatment with the 5 alpha-reductase inhibitor finasteride is associated with problems of ejaculation (2.1-7.7%), erection (4.9-15.8%), and libido (3.1-5.4%). Such significant and undesirable complications in relation to sexual function produce a well-documented negative impact on quality of life. Thus, optimal treatment for men with BPH requires the use of agents that demonstrate efficacy and safety with fewer sexual side effects.

Heat versus drugs in the treatment of benign prostatic hyperplasia

The improvement in symptoms and voiding function is greater with transurethral microwave thermotherapy than with drug therapy, and the associated morbidity is low. Transient urinary retention necessitating catheterization is of short duration after targeted microwave thermotherapy. The short-term effect of microwave thermotherapy can be improved by neoadjuvant and adjuvant alpha-blockade. Microwave treatment offers greater versatility than drug therapy, allowing patients with severe baseline symptoms and small prostates to be treated successfully. Medical management improves symptoms to a more modest extent than does microwave treatment. Finasteride gives comparatively small symptom and flow rate improvements and requires several months for the maximum responses. With alpha-blockers the onset of action is fast and side-effects reversible, although they limit their utility. Finasteride or alpha-blockers must be continued indefinitely to maintain improvements in patients with BPH, but they have a favourable safety and tolerability profile.

Current concepts in the pharmacotherapy of benign prostatic hyperplasia

Benign prostatic hyperplasia is a major men's health issue, with approximately 80% of all men developing this condition within their lifetime. A variety of oral treatments is available, including alpha-adrenoceptor antagonists (alpha-blockers), 5alpha reductase inhibitors, aromatase inhibitors and phytotherapy. A large number of alpha-blockers can be administered, but no single agent has demonstrated a clear superiority over the other drugs. 5alpha Reductase inhibitors have demonstrated similar efficacy in larger volume prostates but most evidence suggests that there is no benefit in combining them with alpha-blockers. The use of phytotherapy is not entirely novel but requires further long-term evaluation before it can be endorsed for clinical use in benign prostatic hyperplasia.

Serenoa repens for benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH), nonmalignant enlargement of the prostate, can lead to obstructive and irritative lower urinary tract symptoms (LUTS). The pharmacologic use of plants and herbs (phytotherapy) for the treatment of LUTS associated with BPH has been growing steadily. The extract of the American saw palmetto or dwarf palm plant, Serenoa repens (also known by its botanical name of Sabal serrulatum), is one of the several phytotherapeutic agents available for the treatment of BPH.

OBJECTIVES

This systematic review aimed to assess the effects of Serenoa repens in the treatment of LUTS consistent with BPH.

SEARCH STRATEGY

Trials were searched in computerized general and specialized databases (MEDLINE, EMBASE, Cochrane Library, Phytodok), by checking bibliographies, and by contacting manufacturers and researchers.

SELECTION CRITERIA

Trials were eligible if they (1) randomized men with BPH to receive preparations of Serenoa repens (alone or in combination) in comparison with placebo or other BPH medications, and (2) included clinical outcomes such as urologic symptom scales, symptoms, or urodynamic measurements. Eligibility was assessed by at least two independent observers.

DATA COLLECTION AND ANALYSIS

Information on patients, interventions, and outcomes was extracted by at least two independent reviewers using a standard form. The main outcome measure for comparing the effectiveness of Serenoa repens with placebo or other BPH medications was the change in urologic symptom scale scores. Secondary outcomes included changes in nocturia and urodynamic measures. The main outcome measure for side effects was the number of men reporting side effects.

MAIN RESULTS

In this update, 3 new trials involving 230 additional men (7.8%) have been included. 3139 men from 21 randomized trials lasting 4 to 48 weeks were assessed. 18 trials were double-blinded and treatment allocation concealment was adequate in 11 studies. Compared with placebo, Serenoa repens improved urinary symptom scores, symptoms, and flow measures. The weighted mean difference (WMD) for the urinary symptom score was -1.41 points (scale range 0-19), (95%CI = -2.52, -0.30, n = 1 study) and the risk ratio (RR) for self rated improvement was 1.76 (95%CI = 1.21, 2.54, n = 6 studies). The WMD for nocturia was -0.76 times per evening (95%CI = -1.22, -0.32; n = 10 studies). The WMD for peak urine flow was 1.86 ml/sec (95%CI = 0.60, 3.12, n = 9 studies). Compared with finasteride, Serenoa repens produced similar improvements in urinary symptom scores (WMD = 0.37 IPSS points (scale range 0-35), 95%CI = -0.45, 1.19, n = 2 studies) and peak urine flow (WMD = -0.74 ml/sec, 95%CI = -1.66, 0.18, n = 2 studies). Adverse effects due to Serenoa repens were mild and infrequent. Withdrawal rates in men assigned to placebo, Serenoa repens or finasteride were 7%, 9%, and 11%, respectively.

REVIEWER'S CONCLUSIONS

The evidence suggests that Serenoa repens provides mild to moderate improvement in urinary symptoms and flow measures. Serenoa repens produced similar improvement in urinary symptoms and flow compared to finasteride and is associated with fewer adverse treatment events. The long term effectiveness, safety and ability to prevent BPH complications are not known. The results of this update are in agreement with our initial review.

Long-term safety and efficacy of a once-daily formulation of alfuzosin 10 mg in patients with symptomatic benign prostatic hyperplasia: open-label extension study

OBJECTIVES

To evaluate the long-term safety and efficacy of a new, once-daily (o.d.) prolonged-release formulation of the clinically uroselective alpha1-blocker, alfuzosin, in patients with symptomatic benign prostatic hyperplasia (BPH).

METHODS

This is a 9-month open-label extension of a 3-month double-blind, placebo-controlled evaluation of alfuzosin 10 mg o.d. and standard alfuzosin 2.5 mg, three times daily (t.i.d.), administered without dose titration in both cases. A total of 311 patients continued in the extension phase and all received alfuzosin 10 mg o.d. Efficacy was evaluated in all patients enrolled in the extension phase (n = 311). Safety was assessed in all patients exposed to alfuzosin, whether in the double-blind or extension phase (n = 360).

RESULTS

Mean international prostate symptom score (IPSS) improved significantly, from 17.1 to 9.3 (P < 0.0001), and mean peak flow rate (PFR) (assessed at through plasma levels) increased significantly, from 9.1 to 11.3 ml/s (P < 0.0001), between baseline (i.e. beginning of the double-blind phase) and the endpoint of the extension phase. Quality of life (QOL) index also improved significantly, from 3.3 to 2.1 (P < 0.0001). Alfuzosin was well tolerated, with only 16 of 360 patients (4.4%) reporting adverse events potentially related to alpha-blockade (mainly dizziness). Ejaculation disorders were infrequent (0.6%) and did not show a relationship to treatment. The incidence of asymptomatic orthostatic hypotension was low (2.8%), and no age effect was identified.

CONCLUSIONS

Alfuzosin 10 mg o.d. provides effective relief from BPH, and clinical benefits are maintained up to 12 months. This study also demonstrates the satisfactory long-term safety of this formulation, and its safe use even in at-risk populations.

Alfuzosin: overview of pharmacokinetics, safety, and efficacy of a clinically uroselective alpha-blocker

Efficacy and safety of alfuzosin administered as 3-times-daily and 2-times-daily formulations have been previously demonstrated in placebo-controlled studies, and these formulations have been commercially available in many countries. A once-daily formulation of alfuzosin administered through a novel prolonged-release system has been recently developed to improve the convenience of dosing and to provide optimal pharmacokinetic coverage over 24 hours. The results of 2 double-blind, placebo-controlled phase 3 studies in patients with lower urinary tract symptoms associated with benign prostatic hyperplasia suggests that 10 mg of alfuzosin administered once daily without dose titration is superior to placebo in terms of symptom and urinary flow rate improvement. Orthostatic hypotension and first-dose phenomenon related to the alpha-blocking property were rare. The incidences of asthenia and fatigue were comparable to those seen with placebo. Ejaculatory disorders were very rare. The most frequently reported adverse event potentially related to alpha blockade was dizziness, which occurred in 5.0% of patients treated with 10 mg alfuzosin compared with 2.1% of patients given placebo.

Terazosin, doxazosin, and prazosin: current clinical experience

Lower urinary tract symptoms (LUTS) suggestive of benign prostatic obstruction are common in aging men. Nearly 25% of men >40 years of age have LUTS. Medical therapy with alpha-blockade is the most common method of medical therapy for benign prostatic obstruction. Multiple methods of minimally invasive surgical therapies have been introduced in the last decade. These methods include balloon dilatation, temporary and permanent urethral stents, various laser techniques, microwave thermotherapy, transurethral needle ablation, electrovaporization, and high-intensity focused ultrasound. alpha-Receptor blockers to reduce the sympathetic tone of the prostate are considered as first-line therapy to relieve the symptoms of benign prostatic hyperplasia. Selective alpha(1)-receptor blockers relax prostatic smooth muscle, relieve bladder outlet obstruction, and enhance urine flow with fewer side effects. In addition, it was determined that treating patients with alpha-blockers increases prostatic apoptosis. Pharmacokinetic activity, mode of action, clinical efficacy, and side effects of the selective alpha(1)-receptor blockers terazosin, doxazosin, and prazosin are reviewed.

Effects of alpha(1)-adrenoceptor (alpha(1)-AR) antagonists on cell proliferation and apoptosis in the prostate: therapeutic implications in prostatic disease

BACKGROUND

Benign prostate hyperplasia (BPH) and prostate cancer established that disruption of the molecular mechanisms that regulate apoptosis and cell proliferation among the stromal and epithelial cell populations, may underlie the neoplastic development that characterizes the aging gland. This work examined the effects of selected alpha(1)-adrenoceptor (alpha(1)-AR) antagonists (blockers) on cellular dynamics to determine whether induction of apoptosis or inhibition of proliferation could contribute to the overall clinical profile.

METHODS

Our efforts were focused on investigating whether alpha(1)-AR antagonists of two different chemical classes affect prostate pathophysiology via mechanisms other than smooth muscle contraction. In in vitro experiments, the two clinically used quinazoline alpha(1)-adrenoceptor antagonists terazosin and doxazosin and the chemically-distinct sulphonamide, tamsulosin, were examined for effects on prostatic tumor growth, by inhibiting cell proliferation and'or inducing apoptosis.

RESULTS

Our findings suggest that alpha(1)-AR antagonists, terazosin and doxazosin, suppress prostatic growth by inducing apoptosis in a dose-dependent manner and without affecting cell proliferation. Tamsulosin exerted no effect on prostate cancer cell growth. The apoptotic effect of terazosin and doxazosin appears to be independent of the alpha(1)-adrenoceptor block.

CONCLUSIONS

Taken together, our findings demonstrate the ability of the quinazoline alpha-blockers, terazosin and doxazosin, but not the sulphonamide, tamsulosin, to suppress prostate growth by inducing apoptosis among the epithelial cells in the benign and malignant prostate. These studies underwrite the durability of the response seen in long-term studies with terazosin, and suggest the potential of this drug in the treatment of prostate carcinoma.

Transurethral microwave thermotherapy: an alternative to medical management in patients with benign prostatic hyperplasia?

Transurethral microwave thermotherapy (TUMT) is being increasingly considered as an alternative to medical management with alpha-blockers or finasteride in patients with lower urinary tract symptoms (LUTS) of benign prostate hyperplasia (BPH). Enduring clinical benefits have been demonstrated after a single 1-hour microwave treatment session under topical anesthesia, and the associated morbidity is low. Optimal results are obtained with the delivery of high thermal doses and accurate targeting of microwave energy. Extensive evidence from randomized clinical trials supports the safety and efficacy of both microwave treatment and medical management, but randomized trial data have only recently become available directly comparing these two approaches to BPH treatment. These data indicate that greater long-term improvements in symptoms, peak urinary flow rates, and quality of life are attained with microwave treatment than with alpha-blockade. Furthermore, the actuarial rate of treatment failure is markedly lower in patients undergoing microwave v alpha-blocker treatment. However, the onset of action of alpha-blocker treatment is more rapid. The principal limitations of alpha-blockade are side effects and lack of efficacy leading to treatment failure in some patients. The maximal effects of finasteride are modest and require a period of months to be manifested, although the side effect profile and tolerability of this agent are favorable. Neoadjuvant and adjuvant alpha-blocker therapy can accelerate symptom and flow rate improvement after TUMT. In contrast to medical management, microwave treatment is highly versatile, allowing patients over a broad range of baseline symptom severities and prostate sizes to be treated with a high probability of success.