Beneficial effects of extended‐release doxazosin and doxazosin standard on sexual health

Abstract

The prevalence of benign prostatic hypertrophy (BPH) and erectile dysfunction (ED) both increase with age, and increasing evidence suggests a common cause rather than independent age‐related changes. Arterial hypertension often accompanies these urological disorders, suggesting the possibility that increased α‐adrenoceptor activity may be causal in all three conditions. As evidence for this model, α‐adrenoceptor antagonists such as doxazosin produce therapeutically beneficial effects in lowering blood pressure, reducing prostate growth and BPH symptoms, and relieving ED. At postjunctional α1‐receptors in the corpus cavernosa, noradrenaline causes vascular smooth muscle cell contraction, restricting blood flow, resulting in penile detumescence. Just as α‐adrenoceptor antagonism results in systemic vasorelaxation to lower blood pressure, the same mechanism in the penis modulates the effects of noradrenaline to favour vasodilatation, resulting in improved erectile function. Increasing clinical evidence attests to the effectiveness of doxazosin in relieving ED, even in patients refractory to ED‐specific treatment, as well as in reducing BPH symptoms and elevated blood pressure.

Molecular mechanisms regulating urogenital expression of nitric oxide synthase in spontaneously hypertensive rats

“…Clinical trial data show that doxazosin, an α 1 -adrenoceptor antagonist, not only relieves the symptoms of benign prostatic hyperplasia, i.e., lower urinary tract symptoms, and reduces blood pressure in patients with hypertension, but also improves erectile dysfunction (Kaplan et al 2006). We have previously demonstrated that doxazosin, but not nifedipine, can partially prevent a decrease in urogenital expression of NOS in SHRs (Yono et al 2007), suggesting that α 1 -adrenoceptor antagonists may contribute to the improvement of lower urinary tract symptoms and erectile dysfunction by facilitating the NO-induced smooth muscle relaxation in the urogenital tissues.…”

Effects of doxazosin on blood flow and mRNA expression of nitric oxide synthase in the spontaneously hypertensive rat genitourinary tract

“…Clinical trial data demonstrate that doxazosin, an α 1 -adrenoceptor antagonist, not only relieves the symptoms of BPH, i.e., lower urinary tract symptoms, and reduces blood pressure in patients with hypertension, but also improves erectile dysfunction Life Sciences 81 (2007) 218 -222 www.elsevier.com/locate/lifescie of patients with and without those concomitant conditions (Kaplan et al, 2006). However, it is not clear whether these improvements using doxazosin are primarily due to direct actions on the prostate, urinary bladder and penis, possibly via inhibition of vascular α 1 -adrenoceptors, or other sites of actions.…”

“…Erectile dysfunction, benign prostatic hyperplasia (BPH) and hypertension occur with increasing prevalence with advancing age, and often occur concomitantly (Kaplan et al, 2006), suggesting a common cause rather than independent age-related changes.…”

LUTS, alpha‐blockers and men's health

“…Since doxazosin has been shown to be mildly beneficial to sexual function, it might be considered the alpha-blocker of choice in this situation. 6 Once the patient is stable on this medication, or alternatively on alfuzosin, a PDE5I such as tadalafil (Cialis) 5mg or sildenafil 25mg (increasing if necessary to 50mg or 100mg) once a day can be safely added without significant risk of inducing postural hypotension.…”