The U.S. Food and Drug Administration approved Rapaflo (silodosin) capsules for the treatment of symptoms due to benign prostatic hyperplasia (BPH), a condition also known as an enlarged prostate.
BPH is a male disease wherein the prostate gland – located between the bladder, which stores urine, and the urethra, the tube through which urine exits the body – enlarges in men as they age. By age 50, roughly 50 percent of all men suffer from BPH. By age 80, that number jumps to 75 percent.
"Benign prostatic hyperplasia can seriously impact the quality of life of men as they age," said George Benson, deputy director, Division of Reproductive and Urological Products, FDA. "This product will provide another treatment option for men suffering symptoms of an enlarged prostate."
As men age, their prostate gland enlarges and begins to press against their urethra. This pressure can impede the flow of urine and make it difficult to eliminate it from the body. In the early stages of BPH, the disease can also create a need to urinate more frequently, or cause dribbling after urination. BPH can also lead to an increased risk of urinary tract infections and urinary retention. Urinary retention can damage the kidneys and cause urinary tract infections by mixing urine from the ureter with urine from the bladder that is heavily laden with bacteria.
Rapaflo works by blocking the alpha-1 adrenoreceptors in the prostate, bladder, and urethra. By blocking these receptors, this treatment allows the smooth muscle in these tissues to relax, resulting in a reduction in BPH symptoms.
Rapaflo will be available in a once-daily capsule. An 8 milligram (mg) daily dose is recommended for men who do not suffer from kidney or liver impairment. A 4 mg daily dose will be available for men with moderate kidney (renal) impairment. Rapaflo is not recommended for men with severe kidney (renal) or liver (hepatic) impairment and is not approved for pediatric use.
The safety and efficacy of Rapaflo were shown in two 12-week, randomized, double-blind, placebo-controlled, multicenter studies using an 8 mg daily dose of Rapaflo. There were 923 male participants in the studies with an average age of 64.6 years. Of the 923, 89.3 percent were Caucasian, 4.9 percent were Hispanic, 3.9 percent were African-American, 1.2 percent were Asian and 0.8 percent were identified as "other." The participants were randomized and, of the 923 patients, 466 received an 8 mg daily dose of Rapaflo. In these studies, Rapaflo produced a statistically significant improvement in BPH symptoms and urinary flow rate when compared to placebo.