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.