May 23 2006
When researchers at the Chang Gung University Medical College, Taiwan and the University of Pittsburgh School of Medicine injected botulinum toxin A, or Botox, into the prostate gland of men with benign prostatic hyperplasia (BPH), a condition commonly referred to as enlarged prostate, they found that it eased symptoms and improved quality of life.
Their results, based on 41 men with the condition, will be presented at the annual meeting of the American Urological Association (AUA) in Atlanta and published in abstract 1436 in the AUA proceedings.
"Millions of men in the United States suffer from enlarged prostate," said Michael B. Chancellor, M.D., professor of urology and gynecology at the University of Pittsburgh School of Medicine. "It's a challenging disease to live with because it causes frequent and difficult urination. Unfortunately, common treatments also are problematic because they carry some risk of serious side effects, such as impotence. Our results are encouraging because they indicate that Botox could represent a simple, safe and effective treatment for enlarged prostate."
The patients, ranging in age from 49 to 79 years, with symptomatic BPH that did not respond to standard medical treatment, received injections of Botox directly into their prostate glands. Thirty-one patients, or 75.6 percent, experienced a 30 percent improvement in urinary tract symptoms and quality of life. These improvements were seen up to one year post-injection in some of the patients. Four out of five patients, or 80 percent, were able to completely empty their bladders within a week to one month after the injection, as the Botox caused the prostate gland to relax, putting less pressure on the urethra. Patients did not experience any significant side effects, including stress urinary incontinence or erectile dysfunction.
According to Dr. Chancellor, Botox reduces the size of the prostate gland through a cellular process called apoptosis, in which the prostate cells die in a programmed manner. This reduction in size can improve urine flow and decrease residual urine left in the bladder.
BPH is one of the most common diseases affecting men as they age. More than half of all men over the age of 60, and 80 percent by age 80, will have enlarged prostates. Forty to 50 percent will develop symptoms of BPH, which include more frequent urination, urinary tract infections, the inability to completely empty the bladder and, in severe cases, eventual damage to the bladder and kidneys
Contributors to the study include Yao-Chi Chuang, M.D., Po-Hui Chiang, M.D., and Kaohsiung Hsien, M.D., with the Chang Gung University Medical College, Taiwan; and Naoki Yoshimura M.D., Ph.D., and Fernando de Miguel, Ph.D., with the University of Pittsburgh School of Medicine. The study is funded by a grant from Allergan.