Usefulness and safety of bunazosin hydrochloride in neurogenic bladder after prolonged administration]

Bunazosin hydrochloride (Ea-0643), a selective alpha 1-blocker, was administered to 14 patients with neurogenic bladder over prolonged periods of time in order to determine its efficacy and safety. Subjective symptoms were classified into 4 grades, and their response assessed after 12 weeks of treatment. The proportion of patients showing improvement by at least one grade was 50.0% for retarded urination, 16.7% for prolonged urination, 25.0% for urinary stream condition, 25.0% for abdominal pressure at voiding, and 28.6% for residual urine. Objective symptoms were also assessed after 12 weeks of treatment, and a statistically significant improvement was recognized in the volume of spontaneously voided urine, the maximum and mean flow rates on uroflowmetry. It should be noted that both of those flow rates had improved significantly only 2 weeks into the treatment. The degree of improvement in subjective and objective symptoms and the degree of general improvement were all higher at week 12 than at week 2 of treatment. Current knowledge of the mechanism of action of this drug, coupled with the observations made in this study, suggests that, once it has improved the urodynamics, it exhibits a sustained effect for prolonged periods of treatment. However, further studies are warranted concerning the mechanisms of the pharmacological action of the drug from a pathological viewpoint. The proportion of patients in whom Ea-0643 was judged to be useful at 12 weeks of treatment was 41.7%, but when the assessment of 'slightly useful' was taken into consideration, the usefulness rate rose as high as 91.7%. Stomatitis was observed in only one case as a side effect of this drug.(ABSTRACT TRUNCATED AT 250 WORDS)