Relief by botulinum toxin of voiding dysfunction due to benign prostatic hyperplasia: results of a randomized, placebo-controlled study.

OBJECTIVES To evaluate the therapeutic role of botulinum toxin injection in men with benign prostatic hyperplasia. METHODS Men with benign prostatic hyperplasia were enrolled in a randomized, placebo-controlled study. After a baseline evaluation, each participant received 4 mL of solution injected into the prostate gland. Patients in the control group received saline solution and patients in the treated group received 200 U of botulinum toxin A. The outcome of each group was evaluated by comparing the symptom scores, serum prostate-specific antigen concentration, prostate volume, postvoid residual urine volume, and peak urinary flow rates. RESULTS Thirty consecutive patients were enrolled. No local complications or systemic side effects were observed in any patient. After 2 months, 13 patients in the treated group and 3 in the control group had subjective symptomatic relief (P = 0.0007). In patients who received botulinum toxin, the symptom score was reduced by 65% compared with baseline values and the serum prostate-specific antigen concentration by 51% from baseline. In patients who received saline, the symptom score and serum prostate-specific antigen concentration were not significantly changed compared with the baseline values and 1-month values. Follow-up averaged 19.6 +/- 3.8 months. CONCLUSIONS Botulinum toxin injected into the prostate seems to be a promising approach for the treatment of benign prostatic hyperplasia. It is safe, effective, and well-tolerated. Furthermore, it is not related to the patient's willingness to complete treatment.