A combination of drugs is significantly more effective than either drug alone for preventing progression of benign prostatic hyperplasia (BPH), especially in high-risk men, according to a study appearing in the Dec. 17 issue of the New England Journal of Medicine.
The Medical Therapy of Prostatic Symptoms (MTOPS) Trial tested whether finasteride (Proscar), doxazosin (Cardura), or a combina- tion of the drugs could prevent progression of BPH and the need for surgery or other invasive treatments. All treatments were compared to placebo.
Physicians at 17 MTOPS medical centers treated 3,047 randomized men with BPH for an average of 4.5 years, longer than previous studies. Vital signs, urinary symptoms, urinary flow, side effects, and medication use were checked every three months. Digital rectal exams were conducted every year, and serum PSA and urine were checked yearly. Prostate size was measured at the beginning and end of the study by ultrasound. Progression of disease was defined by one of the following: a four-point rise in the American Urological Association’s symptom severity score, urinary retention (inability to urinate), recurrent urinary tract infection, or urinary incontinence.
Finasteride and doxazosin together reduced the overall risk of BPH progression by 66% compared to placebo. The combined drugs also provided the greatest symptom relief and improvement in urinary flow rate. Doxazosin alone reduced overall risk of progression by 39% and finasteride alone by 34% relative to placebo. The combination treatment and finasteride alone also significantly reduced the risk of invasive therapy by 67% and 64%, respectively.
MTOPS found that combination therapy was especially effective in men at highest risk for BPH progression — those with prostates larger than 40 mL (30% of participants) or serum PSAs above 4 ng/mL (20% of participants).
BPH progressed in only 5% (49) of men on the two drugs, in 10% (85) of men on doxazosin, in 10% (89 men) of men on finasteride, and in 17% (128 men) of men on placebo. The events signaling disease progression were mostly worsening symptoms (78%), but also included acute urinary retention (12%) and incontinence (9%).