The doxazosin treatment of the changes in the bladder filling phase in benign prostatic hyperplasia

OBJECTIVE: To analyze the clinical and urodynamic efficacy of treatment with doxazosin during 6 months for bladder filling phase disorders in patients with BPH. METHODS: A prospective clinical and urodynamic study was performed in 65 males with BPH, aged 54-79 years (mean 66.7), who had been treated with doxazosin (4 mg/day) during 6 months. Clinical [International Prostatic Symptom Score (IPSS)] and urodynamic evaluations (cystometry and filling cystography) before and after treatment were performed. IPSS data were obtained according to the WHO recommendation following validation and translation into Spanish. RESULTS: The IPSS score improved significantly from 19.8 +/- 4.8 before treatment to 11.9 +/- 4.6 after treatment (p < 0.001). All the patients were normotensive before and after treatment (systolic and diastolic blood pressures 135.9/78.9 and 135.4/77.8 mmHg, respectively). No tachycardia was observed before (71.9 +/- 5.8) or after treatment (71.8 +/- 5.9). A relationship between the lower IPSS before treatment and urinary symptoms improvement was demonstrated (coef.-0.45939). We found no relationship between prostate volume (digital rectal examination or transabdominal ultrasonography) and IPSS modifications after treatment. Bladder instability decreased significantly from 71.6% before treatment to 33.3% after treatment (p < 0.01). Instability pressure also diminished from 99.2 cms H2O to 60.3 cms H2O after doxazosin treatment (p < 0.001). We found no significant relationship between IPSS and bladder instability post-treatment. CONCLUSIONS: Adrenergic blockade with doxazosin 4 mg/day for 6 months achieves a significant decrease in the bladder instability associated with prostatic obstruction in patients with BPH, although no statistical correlation with the IPSS could be demonstrated.