Effect of naftopidil on urethral obstruction in benign prostatic hyperplasia: Assessment by urodynamic studies

Abstract

Thirty-two patients with voiding dysfunction attributable to symptomatic benign prostatic hyperplasia were treated with naftopidil, an alpha 1-blocker, at doses of 25-75 mg/day for 4-6 weeks. The efficacy of the drug was assessed from the changes in urinary symptoms and urodynamic data. Total symptom scores were significantly reduced after treatment (P < 0.001). Average flow rate and maximum flow rate were significantly increased (P < 0.001 and P < 0.001, respectively), and residual urine volume, residual urine rate (ratio of residual urine volume/sum of voided volume and residual urine volume), and maximum urethral closure pressure were significantly (P < 0.05, P < 0.01, and P < 0.05, respectively) reduced, and at bladder capacity, the first desire to void was significantly (P < 0.05) increased. The pressure/flow study demonstrated no changes in intravesical pressure at maximum flow, but a significant (P < 0.05) reduction in minimum urethral resistance. A mild side effect (dizziness) was noted in one patient (3.3%), which soon disappeared after the dose was decreased. The efficacy was good or excellent in 21 of 30 patients (70.0%). The drug was evaluated to be promising in the treatment of bladder outlet obstruction due to benign prostatic hyperplasia.

Detrusor Overactivity and Penile Erection in Patients with Lower Lumbar Spine Lesions

“…Detrusor overactivity, however, has also been reported to occur in other lesions such as benign prostatic hypertrophy [6, 7]. Detrusor areflexia is a typical urodynamic finding in lower lumbar spine lesions [1].…”

“…Such postoperative improvements in detrusor overactivity strongly suggest that the lower lumbar spine lesions caused detrusor overactivity. If detrusor overactivity does not improve after surgery, there may be other causative factors, such as bladder outlet obstruction [6, 7], other neurological disorders and aging. Patients with bladder outlet obstruction and disorders due to other upper motor neurons lesions were excluded from the present study.…”

Influence of hypertension on lower urinary tract symptoms in benign prostatic hyperplasia

“…Alpha-1 adrenergic receptor antagonists (alpha-1 antagonists) decrease the prostatic urethral closing pressure. [2][3][4][5][6] These antagonists have been used for the treatment of BPH, and can not only improve voiding disorders but also assist in the treatment of collecting disorders. 2,5,7 Among non-selective alpha-1 antagonists used for the treatment of BPH, terazosin hydrochloride (terazosin), prazosin hydrochloride, and urapidil have also been employed for the treatment of hypertension.…”

“…[2][3][4][5][6] These antagonists have been used for the treatment of BPH, and can not only improve voiding disorders but also assist in the treatment of collecting disorders. 2,5,7 Among non-selective alpha-1 antagonists used for the treatment of BPH, terazosin hydrochloride (terazosin), prazosin hydrochloride, and urapidil have also been employed for the treatment of hypertension. [8][9][10] Our previous study showed that elderly patients with nocturia had a higher blood pressure and higher serum catecholamine levels when compared with healthy elderly controls.…”

<b>Naftopidil improves locomotor activity and urinary frequency in rats with pelvic venous </b><b>congestion </b>

“…Consequently alpha 1-adrenoceptor antagonists have become the first-line treatment for the relief of BPH symptoms (11). Naftopidil, the alpha 1A/D-adrenoceptor antagonist, has been widely used to BPH because it reduces resistance in the prostatic urethra (31). Multiple studies using rats have shown that naftopidil inhibits the micturition reflex after oral administration (9,22), intravenous injection (2), injection into the medial frontal lobe (14), and after injection into the subarachnoid space at the lumbosacral cord level (26).…”