Use of alpha-adrenergic inhibitors in treatment of benign prostatic hyperplasia and implications on sexual function

Evaluation of silodosin in comparison to tamsulosin in benign prostatic hyperplasia: a randomized controlled trial

Objectives:

Benign prostatic hyperplasia (BPH) is the most common cause of lower urinary tract symptoms in elderly men. Selective alfa₁-adrenergic antagonists are now first-line drugs in the medical management of BPH. We conducted a single-blind, parallel group, randomized, controlled trial to compare the effectiveness and safety of the new alfa₁-blocker silodosin versus the established drug tamsulosin in symptomatic BPH.

Materials and Methods:

Ambulatory male BPH patients, aged above 50 years, were recruited on the basis of International Prostate Symptom Score (IPSS). Subjects were randomized in 1:1 ratio to receive either tamsulosin 0.4 mg controlled release or silodosin 8 mg once daily after dinner for 12 weeks. Primary outcome measure was reduction in IPSS. Proportion of subjects who achieved IPSS <8, change in prostate size as assessed by ultrasonography and changes in peak urine flow rate and allied uroflowmetry parameters, were secondary effectiveness variables. Treatment emergent adverse events were recorded.

Results:

Data of 53 subjects – 26 on silodosin and 27 on tamsulosin were analyzed. Final IPSS at 12-week was significantly less than baseline for both groups. However, groups remained comparable in terms of IPSS at all visits. There was a significant impact on sexual function (assessed by IPSS sexual function score) in silodosin arm compared with tamsulosin. Prostate size and uroflowmetry parameters did not change. Both treatments were well-tolerated. Retrograde ejaculation was encountered only with silodosin and postural hypotension only with tamsulosin.

Conclusions:

Silodosin is comparable to tamsulosin in the treatment of BPH in Indian men. However, retrograde ejaculation may be troublesome for sexually active patients.

[From lab to clinical activity: adrenergic receptors and human uro-genital tissues]

BACKGROUND

Nowadays translational medicine is acquiring a more and more important role in connecting laboratory experimental results on human tissues to clinical findings and drug employment. We want to underline the importance of in vitro studies, which have been extensively performed on animal organs, but few studies have been performed on human tissues. Nevertheless, a more accurate result when compared to the in vivo use of drugs can be given only by testing the very same human tissues in a lab. We related clinical treatments of different pathologies with the results obtained in laboratory studying in vitro fragments of human organs extracted during surgery exposed to different mediators and drugs.

METHODS

Fragments of urethers, bladder (detrusorial muscle and bladder neck muscle fibers), corpora cavernosa, and vas deferens were extracted during demolitive surgery trying not to traumatize the tissue, in order to keep it alive and not to ruin its contractile fibers. The fragments were then put into polisaline solution and, once in the laboratory, fixed on suitable isolated organ support, fixed at one side of the thermostatic pool and on the other side connected to a digital monitoring system. The contractility was then studied after adding different mediators.

RESULTS

The urethers have shown a stronger response to NE and PGF2a, with a different contractility in their distal part due to a major concentration of alpha-receptors; the bladder neck has also shown a strong contractile response to NE and PGF2a, and is inhibited by alpha-blockers; the bladder detrusor, instead, responds to ACH (acetylcholine) and PGF2a; the vas deferens shows a different type of contractility in the prostatic part compared to the epididimary part when stimulated with noradrenaline and PGF2a; the corpora cavernosa respond to NE and PGF2a.

CONCLUSIONS

The results obtained after stimulating the fragments can explain and prove the receptorial activity of inner mediators and of commonly used drugs which have, for years, been used empirically; the simplicity and repetitivity of the method can be considered and used not only to research the physiological functioning of different organs, but also the functioning of new drugs before testing them on patients, being more reliable and accurate than tests on animal tissues. This experimental work has shown that using human tissues in testing specific mediators is the most reliable laboratory method.

The effect of alpha1-adrenergic receptor antagonist tamsulosin (Flomax) on iris dilator smooth muscle anatomy

PURPOSE

To characterize and determine the effect of tamsulosin (Flomax) on the human iris dilator muscle anatomy.

DESIGN

Retrospective, case-control study.

PARTICIPANTS

This study comprised 51 cadaveric eyes from 27 patients (14 with a history of tamsulosin use and 13 control patients) who underwent autopsy at the Duke University Medical Center, Durham, North Carolina.

METHODS

Patients' records were reviewed, and age, medical, surgical, and ocular history; gender; medications; and duration and dosage of tamsulosin were recorded. Specimens were sectioned through the pupillary axis in the horizontal meridian and reviewed by light microscopy. A morphometric analysis was performed to measure the maximum and minimum iris dilator muscle thickness and the iris stromal thickness (micrometers) at 6 points in each eye. All microscopic evaluations and measurements were performed by the same masked observer.

MAIN OUTCOME MEASURES

To determine whether there is a significant difference in the iris dilator muscle or stromal thickness in those patients receiving tamsulosin treatment compared with age-matched controls.

RESULTS

The mean iris dilator muscle thickness in the tamsulosin-treated group (6.53+/-1.99 microm) was significantly thinner compared with that of the control group (8.50+/-1.61 microm) (P=0.006). There was no difference in iris stromal thickness between the 2 groups (P=0.268). There was no direct relationship between duration of tamsulosin use and iris dilator muscle or stromal thickness. Statistical significance was maintained when the iris dilator muscle thickness was compared between the groups using history of diabetes and cataract extraction as separate variables. No difference was noted when comparing the iris stromal thickness using diabetes as a separate variable. However, stromal thickness was significantly different between the groups in pseudophakic eyes (P=0.005).

CONCLUSIONS

According to histologic examination of cadaver eyes, patients receiving tamsulosin treatment exhibited decreased iris dilator muscle thickness compared with control patients. There was no difference noted in the iris stromal thickness within the groups. We believe this finding may shed light on the pathophysiology of intraoperative floppy iris syndrome. Further studies need to be performed to assess the significance of this histologic finding.

Managing enlarged prostate in primary care

Assessment and treatment of benign prostatic hyperplasia, or enlarged prostate, has evolved considerably in recent years; clear evidence has accumulated for the progression of disease over time, the association between disease progression and negative outcomes, and the potential for medical management of this condition. Commensurate with the long-term preventive role of primary care, efforts can and should be made to treat the underlying condition of enlarged prostate as well as to manage the symptoms short-term. This review outlines evaluation of men presenting with lower urinary tract symptoms, examines the challenges for medical treatment and suggests how treatment choice can address these challenges.

"Ejaculatory disorders and alpha1-adrenoceptor antagonists therapy: clinical and experimental researches"

BACKGROUND

It is well known that the use of the alpha-adrenergic receptor antagonists in the BPH therapy may induce ejaculatory disorder. A review of clinical literature shows a greater incidence of ejaculatory disorder during the use of tamsulosin compared with alfuzosin. Anejaculation has been until now referred to retrograde ejaculation due to relaxation of prostatic and bladder neck smooth muscle tone. In a recent researches was evaluated the effect of tamsulosin and alfuzosin on rat vas deferent "in vitro", concluding that tamsulosin may "cause ejaculatory dysfunction by altering the progression and emission of sperm". An abnormal increase of contraction would be the cause of ejaculatory disorder. The aim of our paper is to compare human and rat vas deferens contractile activity and to evaluate with a clinical study if tamsulosin causes retrograde ejaculation disorder.

METHODS

We have revaluated the human and rat vas deferens contractile activity in vitro according to our experience and literature. We have also performed a clinical study on 10 patients (48-72 y) affected by anejaculation. Post-coital urine was examined to search spermatozoa.

RESULTS

Human and rat vas deferens activity is not comparable. Contractile activity induced by norepinephrin after tamsulosin incubation in rat prostatic vas deferens strips is similar to the contractile activity evoked by norepinephrin in human strips. Spermatozoa were found in post coital urine of 6 patients.

CONCLUSION

In our opinion the treatment with tamsulosin may induce retrograde ejaculation but not other ejaculatory disorder due to abnormal sperm progression.

Use of sympathetic alpha antagonists in the management of pediatric urologic disorders

PURPOSE OF REVIEW

To update the physician regarding the use of alpha-adrenergic antagonists in the management of various pediatric urologic problems.

RECENT FINDINGS

The use of alpha-adrenergic antagonist for the treatment of pediatric urologic disorders has expanded greatly over the past decade. This review summarizes the current use of these medications in the treatment of pediatric voiding dysfunction, neurogenic bladder, chronic lower urinary tract symptomatology, idiopathic urethritis, and the passage of ureteral calculi.

SUMMARY

Currently alpha antagonist therapy although not useful in the primary treatment of voiding dysfunction is equivalent in potency to biofeedback therapy for the treatment of recalcitrant voiding dysfunction. In the management of neurogenic bladder and chronic lower urinary tract symptomatology, alpha antagonists working alone or in conjunction with anticholinergic medications will improve clinical symptoms, increase bladder compliance, and decrease detrusor instability. In addition, alpha antagonists may decrease the intensity and duration of symptoms in patients with idiopathic urethritis. Compared with placebo, alpha-adrenergic antagonists will also aid significantly in the spontaneous passage of distal ureteral calculi, thereby reducing the need for surgical intervention and analgesia. The findings noted above significantly expand the clinical usefulness of alpha antagonist therapy within the field of pediatric urology.

Lower urinary tract symptoms and erectile dysfunction: epidemiology and treatment in the aging man

Lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) are common urologic problems that are seen in the aging male population. Until recently, aging itself was considered the common link between ED and LUTS. However, recent studies have shown that the links between these two disease processes are much more complex and are possibly inter-related with a common mechanism. This newly recognized independent relationship between ED and LUTS has the potential to have a profound impact on the way we diagnose and treat these common urologic disorders.

Treatment of lower urinary tract symptoms in benign prostatic hyperplasia and its impact on sexual function

BACKGROUND

Benign prostatic hyperplasia (BPH) is a common disorder in older men and may be associated with lower urinary tract symptoms (LUTS) and sexual dysfunction. Men who present with symptomatic BPH and LUTS are at increased risk for sexual dysfunction, including erectile dysfunction (ED) and ejaculatory dysfunction (EjD).

OBJECTIVE

This review describes treatment options recommended by the 2003 American Urological Association (AUA) guideline panel for the relief of LUTS associated with BPH, with a focus on the effects of each treatment on ED and EjD.

METHODS

Relevant articles were identified via MEDLINE searches of all English-language articles published from January 1984 to January 2005 using the following search terms: benign prostatic hyperplasia and sexual dysfunction, lower urinary tract symptoms and sexual dysfunction, alfuzosin, doxazosin, terazosin, tamsulosin, dutasteride, finasteride, transurethral resection of prostate, erectile dysfunction, and ejaculatory dysfunction. Data on the effects of BPH treatments on sexual function were extracted from the articles and summarized. Because properly designed, adequately powered, direct-comparator studies have not yet been conducted, the AUA's report provides the most comprehensive analyses regarding the efficacy and safety of the current BPH treatment options.

RESULTS

LUTS are an independent risk factor for sexual dysfunction in aging men, even after controlling for age and comorbidities. Although surgery, minimally invasive therapies, and pharmacologic therapies can all improve LUTS and the peak urinary flow rate, some can cause or exacerbate ED (incidence rates: surgery, 10%; minimally invasive therapies, 1%-3%; pharmacologic monotherapy or combination therapy, 3%-10%) and EjD (incidence rates: surgery, 65%; minimally invasive therapies, 4%-16%; pharmacologic monotherapy or combination therapy, 0%-10%). Among pharmacologic therapies for BPH, the frequency of EjD appears to be greater with tamsulosin (10%) than with other alpha(1)-blockers (0%-1%) or the 5alpha-reductase inhibitor finasteride (4%), based on data from a single-arm meta-analysis conducted by the AUA.

CONCLUSION

Sexual function should be assessed and discussed with the patient when contemplating the appropriate management strategy for LUTS associated with BPH, as well as when evaluating the patient's response to treatment.

Combination of phosphodiesterase-5 inhibitors and alpha-blockers in patients with benign prostatic hyperplasia: treatments of lower urinary tract symptoms, erectile dysfunction, or both?

As the prevalence of both erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) increases with age, physicians could be in the position to manage these two conditions simultaneously. Moreover, medical therapies for either one of these conditions can affect the other and this should be carefully considered when making treatment decisions. Pharmacotherapy for benign prostatic hyperplasia (BPH)/LUTS can cause side-effects affecting sexual function. Hence, 5alpha-reductase inhibitors such as finasteride and dutasteride are associated with a greater risk of ED, ejaculatory disorders (EjD) and decreased libido than is placebo. Among alpha1-adrenergic blockers, tamsulosin is associated with an increased risk of EjD. However, some alpha1-adrenergic blockers can also have a positive impact on erection. This is the case for alfuzosin, which has been shown to enhance erectile function in experimental models, probably by reducing the sympathetic tone and thus relaxing corpus cavernosum smooth muscle cells. Phosphodiesterase 5 (PDE-5) inhibitors are commonly used to treat ED. There is increasing evidence that they might also have a beneficial effect on LUTS, probably through the nitric-oxide pathway. Nitric oxide is an important mediator of the relaxation of isolated bladder and urethral smooth muscle, and could modulate prostatic smooth muscle tone. Alpha1-adrenergic blockers and PDE-5 inhibitors can therefore have a positive impact on both ED and LUTS. Although placebo-controlled studies are needed to confirm the impact of these drugs, alone or combined, on both ED and LUTS, this reinforces the need for a common approach to managing these two highly prevalent and bothersome conditions.

Efficacy and safety of alfuzosin 10 mg once daily in the treatment of symptomatic benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a common disorder in ageing men. Patients with BPH often present with bothersome irritative and obstructive lower urinary tract symptoms -- urgency, frequency, nocturia, feeling of insufficient bladder emptying and weak or intermittent flow. alpha(1)-Blockers are the most frequently prescribed oral medications for the first-line treatment of the symptoms associated with BPH. Alfuzosin is a uroselective alpha(1)-blocker that relaxes the smooth muscle of the bladder neck and prostate gland to alleviate BPH symptoms. A pooled analysis of three phase III trials confirmed that treatment with alfuzosin 10 mg q.d. significantly improves the peak urinary flow rate and symptom severity compared with placebo treatment. Unlike some other alpha(1)-blockers, alfuzosin 10 mg q.d. is associated with a low incidence of sexual and vasodilatory side effects. Based on the clinical trials reviewed, alfuzosin 10 mg q.d. is an effective and well-tolerated treatment for the urinary symptoms associated with BPH.

Ejaculatory disorders and lower urinary tract symptoms

A growing body of literature supports the observed association between lower urinary tract symptoms and sexual dysfunction. The causal relationship between these two conditions has not been determined. Ejaculatory function is an important aspect of sexual functioning and recent studies have shown a high prevalence of this ejaculatory dysfunction in men with lower urinary tract symptoms. Furthermore, the degree of bother associated with ejaculatory dysfunction is quite high, making it an important problem for patients. Thus, health care providers should have a heightened sense of awareness for the presence of ejaculatory dysfunction and appropriate patient counseling should be undertaken before initiation of specific treatments for lower urinary tract symptoms.