[Doxazosin treatment of disorders of the voiding phase in benign prostatic hyperplasia]

To analyze the clinical and urodynamic efficacy of treatment with doxazosin during 6 months for voiding phase disorders in patients with BPH.

A prospective clinical and urodynamic study (before and after treatment) was performed in 65 consecutive male patients with BPH, aged 54-79 years (mean 66.7), to evaluate the results of treatment with doxazosin 4 mg/day during 6 months. Clinical evaluation included patient history and the International Prostatic Symptom Score (IPSS) and urodynamic evaluation included uroflowmetry with post-void residual data and pressure-flow test. A static urethral pressure profile was associated with the urodynamic voiding study.

The IPSS score improved significantly from 19.8 +/- 4.8 before treatment to 11.9 +/- 4.6 after treatment (p < 0.001). Urinary symptoms improved significantly more markedly after treatment (coeff. -0.45939) in patients with a lower IPSS score. The symptomatic improvement demonstrated by the IPSS did not correlate with the DRE or the transabdominal US prostatic volume. Mean maximum flow rate before treatment was 9.13 ml/sec and increased to 16.23 ml/sec after treatment (p < 0.01). Postvoid residual dropped from 21.7% to 12.5% (p < 0.01). In the pressure-flow test, foot-point PURR dropped significantly from 69 cms H2O to 45.9 cms H2O (p < 0.001). The PURR curvature diminished from 0.27416 to 0.15964 cms H2O (ml/sec2) (p < 0.01). A statistically significant improvement of the compressive (p < 0.001) and constrictive (p < 0.05) elements of lower urinary tract obstruction was observed. The urethral functional length of the urethral profile showed a significant reduction (pre-treatment: 5.56 cms; post-treatment 4.31 cms) (p < 0.05). A statistical correlation was found between the urethral functional length and the foot-point PURR post-treatment.

Adrenergic blockade with doxazosin reduces both the compressive and constrictive elements of lower urinary tract obstruction in the voiding phase in patients with BPH, although no statistical correlation with the IPSS could be demonstrated.