Two Drugs Better Than One for Enlarged Prostate
The combination of two drugs, dutasteride and tamsulosin, is more effective at reducing progression of an enlarged prostate than either drug taken alone. That is the finding of researchers from the University of Texas Southwestern Medical Center.
An enlarged prostate, or benign prostatic hypertrophy (BPH), is characterized by urinary frequency, urgency, the need to urinate often at night, weakened urine stream, and incomplete bladder emptying. Approximately 19 million men in the United States have symptomatic BPH, and 14 million of them are undiagnosed, according to the National Association of Continence. Two million men are diagnosed but are not receiving treatment.
As many as 50 percent of men experience symptoms of an enlarged prostate by age 60, and 90 percent of men report symptoms by age 85. The prostate gland typically undergoes two stages of growth: the first is early in life and is complete by the end of puberty; the second stage may begin around age 40.
Two drugs that are often prescribed for symptoms of an enlarged prostate are dutasteride (Avodart®, a 5-alpha reductase inhibitor) and tamsulosin (Flomax®, an alpha blocker), which typically are not prescribed together. But a research team from UT Southwestern Medical Center decided to compare each of these drugs individually and combined in a group of more than 4,800 men with BPH over a four-year period.
The study participants were divided into three treatment groups: dutasteride alone, tamsulosin alone, and both drugs. Dr. Claus Roehrborn, chairman of urology at UT Southwestern and the lead author of the study, notes that they found the two drugs combined “to be superior at reducing risk of BPH progression.” Among the men who received the combination therapy, there was a 25 percent reduction in prostate volume, and these men reported fewer symptoms than those in the other two treatment groups.
Another significant finding in the combination group was a 50 percent reduction in the level of prostate-specific antigen (PSA), the protein that can indicate an increased risk of cancer. Both cancerous and noncancerous prostate cells are capable of producing PSA, thus a rise in this level does not always indicate cancer, although cancer cells usually produce more PSA than do benign cells.
Compared with men in the tamsulosin-only group, men in the combination treatment group also experienced a 67 percent reduction in the incidence of acute urinary retention and a 70 percent reduced need for surgery for BPH. When comparing the combination group with the dutasteride-only group, there was a 19 percent decrease in the risk of acute urinary retention or BPH-related surgery.
These two drugs appears to be better than one for treatment of an enlarged prostate, but currently there is no one drug physicians can prescribe that provides both dutasteride and tamsulosin. Dr. Roehrborn notes that their research “should provide physicians better information when they decide on a course of treatment for patients with BPH.”
National Association for Continence
University of Texas Southwestern Medical Center