Medical Treatment of Lower Urinary Tract Symptoms Suggestive of Benign Prostatic Hyperplasia

Potential side effects of currently available pharmacotherapies in male lower urinary tract symptoms suggestive of benign prostatic hyperplasia

INTRODUCTION

The drug classes of α1-adrenoceptor antagonists, 5α-reductase inhibitors, and phosphodiesterase type 5 inhibitors are guideline-recommended treatments of lower urinary tract symptoms suggestive of benign prostatic hyperplasia; muscarinic receptor antagonists and β3-adrenoceptor agonists are also recommended if storage symptoms are insufficiently addressed with one of the other three drug classes.

AREAS COVERED

We provide a narrative review (no formalized literature searches performed) of the tolerability of these drug classes with emphasis on the more recently introduced medications, on combination treatment, and on more lately emerging risks.

EXPERT OPINION/COMMENTARY

The tolerability profiles are distinct between drug classes but, with few exceptions, similar within a drug class. Within a drug, formulations with longer duration of action tend to have better tolerability. Efficacy gains using combination treatment at least partly come at a cost of lesser tolerability. Greater susceptibility to experience adverse events based on age, comorbidities, and comedications appears conceptually important but remains under-investigated in this therapeutic area.

Simple Modification of the Bladder Outlet Obstruction Index for Better Prediction of Endoscopically-Proven Prostatic Obstruction: A Preliminary Study

Purpose

The bladder outlet obstruction index (BOOI), also known as the Abrams-Griffiths (AG) number, is the most widely used index for predicting BOO. However, the obstructed prostatic urethra determined by the BOOI is often inconsistent with endoscopically-proven obstruction. We assessed abdominal straining pattern as a novel parameter for improving the prediction of BOO.

Materials and Methods

We retrospectively reviewed the pressure-flow studies (PFS) and cystourethroscopy in 176 BPH/LUTS patients who were unresponsive to medical therapy. During PFS, some groups of patients tried to urinate with abdominal straining, which can increases intravesical pressure and underestimate BOOI theoretically. Accordingly, the modified BOOI was defined as (P_detQ_max+ΔP_abd)-2Q_max.

Results

Ultimately, 130 patients were eligible for the analysis. In PFS, ΔP_abd (P_abdQ_max-initial P_abd) was 11.81±13.04 cmH₂O, and it was 0–9 cmH₂O in 75 (57.7%), 10–19 cmH₂O in 23 (17.7%) and ≥20 cmH₂O in 32 (24.6%) patients. An endoscopically obstructed prostatic urethra in 92 patients was correctly determined in 47 patients (51.1%) by the original BOOI versus 72 patients (78.3%) based on the modified BOOI. Meanwhile, an “unobstructed” urethra according to the original BOOI was present in 11 patients (12.0%), whereas according to the modified BOOI, only 2 (2.1%) would be labeled as “unobstructed”. In receiver operating characteristic curves, the area under the curve was 0.906 using the modified BOOI number versus 0.849 in the original BOOI (p<0.05).

Conclusions

The change in abdominal pressure was correlated with endoscopically-proven obstruction. Our simple modification of the BOOI on the basis of this finding better predicted bladder outlet obstruction and, therefore, should be considered when evaluating BOO in patients with LUTS/BPH.

Custom 4-Plex DiLeu Isobaric Labels Enable Relative Quantification of Urinary Proteins in Men with Lower Urinary Tract Symptoms (LUTS)

The relative quantification of proteins using liquid chromatography mass spectrometry (LC-MS) has allowed researchers to compile lists of potential disease markers. These complex quantitative workflows often include isobaric labeling of enzymatically-produced peptides to analyze their relative abundances across multiple samples in a single LC-MS run. Recent efforts by our lab have provided scientists with cost-effective alternatives to expensive commercial labels. Although the quantitative performance of these dimethyl leucine (DiLeu) labels has been reported using known ratios of complex protein and peptide standards, their potential in large-scale proteomics studies using a clinically relevant system has never been investigated. Our work rectifies this oversight by implementing 4-plex DiLeu to quantify proteins in the urine of aging human males who suffer from lower urinary tract symptoms (LUTS). Protein abundances in 25 LUTS and 15 control patients were compared, revealing that of the 836 proteins quantified, 50 were found to be differentially expressed (>20% change) and statistically significant (p-value <0.05). Gene ontology (GO) analysis of the differentiated proteins showed that many were involved in inflammatory responses and implicated in fibrosis. While confirmation of individual protein abundance changes would be required to verify protein expression, this study represents the first report using the custom isobaric label, 4-plex DiLeu, to quantify protein abundances in a clinically relevant system.

Urine chemokines indicate pathogenic association of obesity with BPH/LUTS

OBJECTIVES

High prevalence of lower urinary tract symptoms (LUTS) consistent with benign prostate hyperplasia (BPH) is associated with obesity and prostatic inflammation. Here, we investigated whether chemokines associated with obesity and prostatic inflammation can be measured in normally voided urine of BPH/LUTS patients to demonstrate the mechanistic association between obesity and BPH/LUTS.

METHODS

Frozen urine specimens of BPH/LUTS patients enrolled in the Nashville Men's Health Study were sent for blinded analysis to University of Pittsburgh. Thirty patients were blocked by their AUA-SI (>7 or ≤7) and prostatic enlargement (<40, 40-60, >60 cc). Clinical parameters including age, prostate size, and medications were derived from chart review. CXC chemokines (CXCL-1, CXCL-8, and CXCL-10), CC chemokines (CCL2 and CCL3), and sIL-1ra were measured in thawed urine using Luminex™ xMAP(®) technology and ELISA for NGF.

RESULTS

Urinary CCL2 levels were several fold higher compared with the other six proteins, of which CCL3 was detectable in less than one-fourth of patients. Urine levels of sIL-1ra and CXCL-8 were significantly associated with increasing BMI and waist circumference in BPH patients. CXCL-8 showed a marginal association with overall AUA-SI scores, as well as obstructive (p = 0.08) symptom subscores. Prostate volume was inversely and marginally associated with urinary CXCL-10 (p = 0.09).

CONCLUSIONS

Urine levels of CXCL-8, CXCL-10, and sIL-1ra were associated with varying degrees with LUTS severity, prostate size, and obesity, respectively. These findings in urine are consistent with past studies of chemokine levels from expressed prostatic secretions and demonstrate the potential of noninvasively measured chemokine in urine to objectively classify BPH/LUTS patients.

EAU guidelines on the treatment and follow-up of non-neurogenic male lower urinary tract symptoms including benign prostatic obstruction

OBJECTIVE

To present a summary of the 2013 version of the European Association of Urology guidelines on the treatment and follow-up of male lower urinary tract symptoms (LUTS).

EVIDENCE ACQUISITION

We conducted a literature search in computer databases for relevant articles published between 1966 and 31 October 2012. The Oxford classification system (2001) was used to determine the level of evidence for each article and to assign the grade of recommendation for each treatment modality.

EVIDENCE SYNTHESIS

Men with mild symptoms are suitable for watchful waiting. All men with bothersome LUTS should be offered lifestyle advice prior to or concurrent with any treatment. Men with bothersome moderate-to-severe LUTS quickly benefit from α1-blockers. Men with enlarged prostates, especially those >40ml, profit from 5α-reductase inhibitors (5-ARIs) that slowly reduce LUTS and the probability of urinary retention or the need for surgery. Antimuscarinics might be considered for patients who have predominant bladder storage symptoms. The phosphodiesterase type 5 inhibitor tadalafil can quickly reduce LUTS to a similar extent as α1-blockers, and it also improves erectile dysfunction. Desmopressin can be used in men with nocturia due to nocturnal polyuria. Treatment with an α1-blocker and 5-ARI (in men with enlarged prostates) or antimuscarinics (with persistent storage symptoms) combines the positive effects of either drug class to achieve greater efficacy. Prostate surgery is indicated in men with absolute indications or drug treatment-resistant LUTS due to benign prostatic obstruction. Transurethral resection of the prostate (TURP) is the current standard operation for men with prostates 30-80ml, whereas open surgery or transurethral holmium laser enucleation is appropriate for men with prostates >80ml. Alternatives for monopolar TURP include bipolar TURP and transurethral incision of the prostate (for glands <30ml) and laser treatments. Transurethral microwave therapy and transurethral needle ablation are effective minimally invasive treatments with higher retreatment rates compared with TURP. Prostate stents are an alternative to catheterisation for men unfit for surgery. Ethanol or botulinum toxin injections into the prostate are still experimental.

CONCLUSIONS

These symptom-oriented guidelines provide practical guidance for the management of men experiencing LUTS. The full version is available online (www.uroweb.org/gls/pdf/12_Male_LUTS.pdf).

Evaluation of the clinical value of a simple flowmeter in the management of male lower urinary tract symptoms

Study Type - Diagnostic (exploratory cohort) Level of Evidence 3b What's known on the subject? and What does the study add? Electronic uroflowmetry reasonably predicts the likelihood of bladder outlet obstruction (BOO) and risk of AUR. This low-cost device, Uflowmeter(™) , allows men to perform uroflowmetry at home with ease and the results are compatible with that of electronic uroflowmentry. It can also estimates risk of AUR and the need for TURP to relieve LUTS.

OBJECTIVE

To show the clinical value of a simple flowmeter, which has been devised to measure uroflow on an ordinal scale (<10, 10-15, 15-19 and >19 mL/s) at home, for the management of male lower urinary tract symptoms (LUTS).

PATIENTS AND METHODS

A total of 186 men with LUTS were enrolled in the study. The mean (range) follow-up was 220 (68-431) days. The men's mean (range) age was 65.5 (46-83) years, mean (range) maximum urinary flow rate (Qmax) 12.8 (4.3-39.5) mL/s, mean (range) voided volume 294.8 (151-686) mL; mean (range) postvoid residual urine volume (PVR) 50 (0-303) mL and mean (range) International Prostate Symptom Score (IPSS) 13.5 (1-31). The men underwent electronic uroflowmetry ('clinic uroflowmetry') and completed an IPSS questionnaire in the clinic. They then conducted 10 measurements with the device at home ('home uroflowetry'). The uroflowmetry and IPSS questionnaire were repeated 2 weeks later. Quadratically weighted Kappa analysis (κ) of the home uroflowmetry vs. clinic uroflowmetry, and of the sensitivity and specificity of the home uroflowmetry values to correspond to the mean Qmax of clinic uroflowmetry (<10, 10-15, 15-19 and >19 mL/s) was performed. Similar analyses were performed for the IPSS. Kaplan-Meier analysis was performed to evaluate whether home uroflowmetry was able to prognosticate acute urinary retention (AUR) or the need for transurethral resection of the prostate (TURP).

RESULTS

The home uroflowmetry values (κ= 0.84, 95% confidence interval [CI]: 0.78-0.90) were superior to the IPSS (κ= 0.083; 95% CI: 0-0.173) in correlating with the mean Qmax of clinic uroflowmetry. Home uroflowmetry was most sensitive in identifying a mean Qmax of >19 mL/s (sensitivity: 0.99; 95% CI:0.97-1.00) and most specific in identifying a mean Qmax of <10 mL/s (specificity: 0.90; 95% CI:0.83-0.94). The home uroflowmetry works best in ruling out a mean Qmax of <19 mL/s (diagnostic odds ratio [DOR]= 349.3; 95% CI:40.24-3037.7), followed by a mean Qmax of <15 mL/s (DOR = 91.02; 95% CI:31.23-265.23) and a mean Qmax of <10 mL/s (DOR = 32.04; 95% CI:14.0-73.19). Men with a home uroflowmetry value ≤10 mL/s were more likely (n= 6; 8.8%) than those with a home uroflowmetry value >10 mL/s (n= 2; 1.7%) to develop AUR or require TURP (log-rank test: P= 0.017; hazard ratio:5.61(95% CI:1.10-28.64)). The IPSS failed to display the same discriminative capability.

CONCLUSION

Home uroflowmetry using this simple device is a satisfactory estimation of clinic uroflowmetry using an electronic flowmeter and can predict the significant progression of male LUTS.

The forefront for novel therapeutic agents based on the pathophysiology of lower urinary tract dysfunction: alpha-blockers in the treatment of male voiding dysfunction - how do they work and why do they differ in tolerability?

alpha(1)-Adrenoceptor antagonists are the mainstay of medical treatment of male voiding dysfunction which typically is attributed to benign prostatic hyperplasia. While original concepts have assumed that they relieve voiding dysfunction by relaxing prostatic smooth muscle, newer data indicate that their therapeutic effects at least partly occur independent of prostatic relaxation, perhaps involving direct effects on blood vessels, urothelium, afferent nerves, and/or smooth muscle of the urinary bladder. The adverse event profiles differ among alpha(1)-adrenoceptor antagonists, with tamsulosin having a particularly good cardiovascular tolerability. While this was originally attributed to its selectivity for alpha(1A)-adrenoceptors, it appears that alfuzosin which lacks subtype-selectivity, has a very similar tolerability. In contrast, doxazosin and terazosin, which are chemically and pharmacologically more closely related to alfuzosin than to tamsulosin, appear to have more side effects attributable to the cardiovascular system. More recent data indicate that tolerability differences between alpha(1)-adrenoceptor antagonists may at least partly relate to pharmacokinetic rather than to pharmacodynamic differences. Taken together, these data emphasize the idea that concepts about drug efficacy and tolerability despite being highly plausible may not necessarily be true and always require thorough experimental testing.