Q: My doctor diagnosed benign prostatic hyperplasia (BPH) as the cause for my difficulties in urination. Because my symptoms were not too troublesome and I wanted to avoid surgery, treatment with finasteride was tried for about six months; but there was little improvement in my symptoms. Now my doctor has suggested Hytrin, a drug that is supposed to work in a different way than finasteride. I would appreciate information on this drug.
A: BPH is an enlargement of the prostate gland that obstructs the flow of urine as it passes from the bladder through the prostate by putting pressure on the urethra.
The symptoms caused by BPH (referred to as prostatism) include difficulty in starting to urinate, a weak stream of urine, dribbling at the end of urination, frequent urination, the sensation that the bladder is not empty after urination is completed and awakening at night to urinate. The urethra is constricted not only by the overgrowth of prostatic tissue, but also by the contraction of smooth muscles present within the prostate.
Finasteride shrinks the prostate gland and in this way may relieve the symptoms of BPH. Terazasin (Hytrin) is one of a group of drugs, called alpha-adrenergic antagonists, that can decrease pressure on the urethra by relaxing smooth muscle tissue in the prostate. Hytrin is the only drug in this class approved by the Food and Drug Administration for the treatment of BPH.
In trials comparing Hytrin with a sugar pill, men taking high doses of Hytrin had a greater improvement in their prostatism than those taking the placebo. Overall, it appears that about 30 percent of men have a satisfactory response to Hytrin.
Another effect of alpha-adrenergic antagonists is to lower blood pressure by relaxing smooth muscles in the walls of small arteries, and studies with Hytrin have shown a significant reduction in blood pressure in men treated for BPH. Lowering blood pressure is fine in men with high blood pressure, but it is probably also responsible for the dizziness that is a side effect in about 10 percent of men taking a dose large enough to improve symptoms of prostatism.
In order to avoid such side effects, the drug is usually started at the lowest possible dose, then gradually increased to reach the most benefit and least side effects.
Hytrin has other positive features: when effective, it improves symptoms more quickly than finasteride; it improves serum lipid levels; it has no adverse effects on sexual function; and, unlike finasteride, it does not lower the blood level of PSA, which is often used as a screening test for the early detection of prostate cancer.
Since finasteride and Hytrin act in different ways, your experience with finasteride does not mean that Hytrin won't work. So it seems reasonable to give Hytrin a try. You might wonder whether the combination of finasteride and Hytrin would be more effective than either one alone. Such combinations might prove useful in the future, but further trials are needed to answer the question.
Dr. Margolis is professor of medicine and biological chemistry at the Johns Hopkins School of Medicine.