Alpha-blockers in benign prostatic hyperplasia

Selecting therapy for maintaining sexual function in patients with benign prostatic hyperplasia

In the first of these mini-reviews the selection of therapy for the maintenance of sexual function in patients with BPH is outlined, along with an explanation of how altered regulation of neurotransmitters, especially noradrenaline, may underlie the syndrome of LUTS and sexual dysfunction. Other mini-reviews outline the current status of robotic surgery to treat renal and adrenal disorders, and its future applications, and the potential use of the nitric oxide/cGMP pathway as a potential target to treat BOO associated with benign prostatic enlargement. Finally, the capacity to be creative in academic departments is extolled as a core property of academicians, and its surfacing described as having the potential to revitalize individuals and departments.

Change in parameters before and after alpha-1-blocker therapy for men with lower urinary tract symptoms using color doppler ultrasound urodynamics: possible application for prediction of clinical outcome

INTRODUCTION

We previously developed a noninvasive video urodynamic study using color Doppler ultrasonography. We sought the best flow velocity-related parameter which would allow prediction of an improvement in lower urinary tract symptoms (LUTS) after alpha 1-blocker treatment.

METHODS

Twenty-two men with benign prostatic hyperplasia who were treated with a nonselective alpha 1-blocker (urapidil) were included. Subjective symptoms were evaluated using the International Prostate Symptom Score (IPSS) before and after alpha 1-blocker treatment. We measured the flow velocities using a transperineal ultrasound technique in the distal prostatic urethra just proximal to the external urethral sphincter (V1) and in the sphincteric urethra (V2), and used them to obtain the velocity ratio (VR=V1/V2). The corresponding functional cross-sectional areas of the urethra at these two sites (A1 and A2) were calculated as Q(max)/V. All these parameters obtained by the velocity-flow urodynamics were compared before treatment and after 4 weeks.

RESULTS

After treatment, V1 and VR were decreased, and A1 was increased. V2 correlated best with the change in IPSS before and after alpha 1-blocker therapy, with Spearman's rho of 0.584. All men with V2 exceeding 50 cm/s did not show an improvement in the LUTS.

CONCLUSIONS

The maximum flow velocity at the sphincteric urethra (V2) can predict the subjective outcome of alpha 1-blocker treatment. The velocity-flow parameters changed after alpha 1-blocker treatment. We confirmed that the transperineal ultrasound urodynamic study is not only noninvasive but also informative.

Apoptotic impact of alpha1-blockers on prostate cancer growth: a myth or an inviting reality?

BACKGROUND

Pharmacological manipulation or genetic targeting of the major apoptosis regulators, such as bcl-2, caspases, and inhibitors of apoptosis (IAPs), represent clinically attractive avenues towards effective therapeutic strategies for advanced prostate cancer. A wealth of evidence established the alpha(1)-adrenoceptor antagonists to be clinically effective in relieving the symptoms associated with benign prostatic hyperplasia (BPH) by relaxing prostatic smooth muscle tone. This action alone however does not fully account for the long-term clinical response to these drugs in BPH patients.

METHODS

Experimental and retrospective clinical studies provided new evidence supporting a differential growth-suppressing function of two alpha(1)-adrenoceptor antagonists against prostate cancer, independent of an alpha(1)-adrenoceptor mechanism.

RESULTS

The quinazoline-based antagonists, doxazosin and terazosin, induce apoptosis, inhibit cell adhesion to the extracellular matrix (by activating anoikis), and prevent cell invasion and migration of prostate tumor epithelial cells and vascular endothelial cells. Tamsulosin, a sulphonamide-based, clinically effective alpha(1)-adrenoceptor antagonist for BPH treatment, fails to exert a similar apoptotic action against prostate cells. Furthermore, at pharmacologically relevant doses, doxazosin suppresses benign and malignant prostate growth in in vivo experimental models. The effect is characterized by three intriguing features: (a) it is mediated by an alpha(1)-adrenoceptor-independent action, (possibly related to the quinazoline nucleus); (b) it is targeted at the apoptotic process without affecting cell proliferation; and (c) the elevated apoptotic index correlated with symptom score improvement in BPH patients.

CONCLUSIONS

This evidence challenges conventional knowledge of the mechanism of action of alpha(1)-adrenoceptor antagonists, and points to a new therapeutic value for these drugs by providing a differential molecular basis for their anti-tumor efficacy. The present review focuses on the characterization of the apoptotic/anti-angiogenic effect of quinazoline-based alpha(1)-adrenoceptor antagonists against prostate cancer cells and discusses the clinical significance of this action in the prevention and treatment of prostate cancer.