Urodynamic effects of silodosin, a new alpha 1A-adrenoceptor selective antagonist, for the treatment of benign prostatic hyperplasia

AIMS

To investigate urodynamically the effects of silodosin, a new alpha(1A)-adrenoceptor-selective antagonist, in the treatment of benign prostatic hyperplasia (BPH).

METHODS

Thirty six male patients with BPH (69.9 +/- 7.3 years), who were referred as candidates for surgery, were treated with silodosin (4 mg twice daily). The total International Prostate Symptom Score (IPSS) was 20.7 +/- 7.4, maximum flow rate (Q(max)) was 6.7 +/- 3.0 ml/sec, and prostate volume was 45.6 +/- 24.5 ml.

RESULTS

Total IPSS, storage and voiding symptom subscores and QOL score decreased significantly, and Q(max) increased significantly after 1-12 months of therapy (all P < 0.05). In urodynamic study (n = 29), maximum cystometric capacity increased significantly (P = 0.0027), and detrusor overactivity disappeared in 8 of 20 patients (40%) and improved (bladder capacity increased more than 50%) in 7 (35%) after the therapy. In pressure/flow studies (n = 27), the obstruction grade was improved in 15 patients (56%). Detrusor opening pressure, detrusor pressure at Q(max), bladder outlet obstruction index, and Schäfer's obstruction class decreased significantly after therapy (all P < 0.01). After 12 months, 16 patients (44%) are still on silodosin for 23.3 +/- 7.0 (range 12-36) months, and the improvements in IPSS and Q(max) were stable. Twenty patients withdrew because of insufficient effectiveness in 13 patients (12 patients underwent surgery), side effects in 3, and unknown reasons in 4.

CONCLUSION

Silodosin appears to improve detrusor overactivity and obstruction grade in patients with BPH. With silodosin treatment, LUTS could be managed effectively for more than a year in at least 44% of the patients.

Effects of Silodosin on Lower Urinary Tract Symptoms in Patients with Benign Prostatic Hyperplasia: Evaluation by Frequency/Volume Chart

OBJECTIVES

To prospectively evaluate the efficacy of silodosin, a new α1A -adrenoceptor selective antagonist, for the treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) on the basis of a frequency/volume chart.

METHODS

Forty male patients (71.1 ± 6.6 years old) with LUTS/BPH were treated with silodosin (4 mg twice daily). The effects of the drug were assessed by changes in International Prostate Symptom Score, uroflowmetry, and frequency/volume chart at 1 and 3 months after therapy.

RESULTS

The mean total International Prostate Symptom Score, the mean total storage and voiding scores and the mean quality of life score decreased significantly at 1 and 3 months after therapy (all P < 0.01). Average and maximum flow rates increased significantly, and postvoid residual volume decreased significantly after 1 and 3 months (all P < 0.05). The frequency/volume chart showed that daytime frequency in those who initially voided over eight times/day (n = 12) decreased significantly (P = 0.0391) after 1 month, and nighttime frequency in those who initially voided over two times (n = 16) tended to decrease (P = 0.0833) after 3 months. Mean voided volume in those who initially voided less than 250 mL (n = 31) increased significantly after 1 and 3 months (P = 0.0446 and P = 0.0138, respectively), and maximum voided volume in those who initially voided less than 300 mL (n = 18) tended to increase (P = 0.0833) after 1 month.

CONCLUSION

Silodosin appears to be effective for both storage and voiding symptoms by increasing bladder capacity in patients with LUTS/BPH.