[Clinical efficacy of oxendolene (antiandrogen) and bunazosin hydrochloride (alpha-adrenergic blocker) in the treatment of prostatism--comparative study of oxendolone, bunazocin hydrochloride and their combination].

Antiandrogen and alpha-adrenergic blockers have recently been tried in the medical treatment for benign prostatic hypertrophy and bladder neck contracture. We herein report our results of a randomized comparative study on the clinical efficacy of oxendolone, bunazosin hydrochloride (bunazosin) and their combination for the treatment of benign prostatic hypertrophy and bladder neck contracture. The attending doctors evaluated at twelve weeks the improvement rate for three treatment regimens, 400 mg/day oxendolone, 3 mg/day bunazosin and a combination of both. Oxendolone + bunazosin showed the highest improvement rate in the evaluation of each subjective symptom and objective finding and of both. Oxendolone + bunazosin tended to show a better clinical efficacy than the other of these regimens, when the improvement was defined as that with more than one degree in the severity of retarded voiding, prolonged voiding, urinary stream condition, abdominal pressure on voiding and residual urine sensation. The improvement of such subjective symptoms seemed to occur earlier with oxendolone + bunazosin or bunazosin than with oxendolone. A significant difference was shown among the three treatment regimens in the general improvement rate on four subjective symptoms, with oxendolone + bunazosin being the highest followed by bunazosin and oxendolone in this order. The improvement rates of maximum and mean flow rate which are most important parameters to evaluate the voiding condition, at twelve weeks were significantly higher with oxendolone + bunazosin. No serious side effects were observed in this study, although treatment regimens containing bunazosin caused some minor side effects. These side effects could be prevented by the use of initial low doses of bunazosin with a subsequent gradual increment up to 3 mg/day. Taking the differences in the mechanism of oxendolone and bunazosin and the results of our study into consideration, we believe that the combination of oxendolone and bunazosin would be more useful in a clinical situation.