Medication Therapies
If you need treatment for symptoms due to benign prostatic hyperplasia (BPH), but do not want or need surgery, medication may be a useful choice. Medication has limitations. It is not always completely effective in getting rid of your urinary symptoms, and you have to keep taking it to prevent your symptoms from coming back. But medication also has advantages. It may work well for you, is not invasive, does not require you to heal afterward, and is not associated with the same kinds of complications as surgery or other invasive procedures.
Remember that all medications have potential side effects. Before beginning a new medication, it’s wise to become familiar with them. Talk to your doctor or pharmacist and read the label to make sure you have the correct medication and understand how to take it as recommended.
5-Alpha-Reductase Inhibitors
The 5-alpha-reductase inhibitors include the drugs finasteride (Proscar®) and dutasteride (Avodart®). They block the action of 5-alpha-reductase, an enzyme that normally converts the male hormone testosterone to another type of male hormone, dihydrotestosterone. Dihydrotestosterone stimulates the prostate cell division and is important in prostate growth. As the drugs prevent 5-alpha-reductase from producing dihydrotestosterone, the prostate no longer grows larger and actually begins to shrink.
Finasteride has been shown to improve urine flow and prevent urinary retention (having urine in the bladder after trying to empty it) after about 3 to 6 months. However, it may take as long as a year to see the full benefit of finasteride in improving urinary symptoms. Finasteride also stops or slows down the progression of BPH.
There is more than one type of 5-alpha-reductase enzyme. Finasteride works by blocking 5-alpha-reductase type 2. The drug reduces the levels of dihydrotestosterone by as much as 70 percent in the blood and by as much as 90 percent in the prostate. Over time, in men who continue to take it every day, finasteride may reduce the volume of the prostate gland by about 20 percent.
Studies suggest that finasteride works best in men with larger prostates. It should not be given to men without prostate enlargement. The drug does not affect testosterone levels or the ability of testosterone to stimulate normal male functions. A few men may experience sexual problems (lack of desire, problems with erections or ejaculation) or breast enlargement or tenderness after taking finasteride. However, these side effects are uncommon.
Dutasteride blocks the action of both 5-alpha-reductase type 1 and type 2. This reduces the blood levels of dihydrotestosterone by more than 90 percent in most men. Like finasteride, dutasteride reduces the volume of the prostate, improves urinary symptoms, and stops or slows down the progression of BPH. Dutasteride may work faster than finasteride, although it still takes months to see its full benefits.
Like finasteride, dutasteride works best in men with larger prostates. It should not be prescribed to men with lower urinary tract symptoms (LUTS) who do not have prostate enlargement. Side effects with dutasteride are uncommon, affecting a small percentage of men who take it. When side effects occur, they involve the same kinds of sexual problems or breast enlargement or tenderness that have been reported for finasteride.
Alpha Blockers
The alpha blockers include terazosin (Hytrin®), doxazosin (Cardura®), tamsulosin (Flomax®), and alfuzosin (Uroxatral®). They represent a separate class of drugs for treating BPH that act differently than the 5-alpha-reductase inhibitors. The alpha blockers show their benefits more quickly, within a matter of days.
Alpha-blocking drugs prevent the alpha adrenergic receptors within the autonomic nervous system from being stimulated. This causes certain types of muscle fibers in the body to relax and reverses blood vessel constriction. The alpha blockers were originally found to be useful in lowering blood pressure.
The alpha blockers act more quickly than the 5-alpha-reductase inhibitors in relieving urinary symptoms due to BPH. After a man takes an alpha blocker, the drug acts to relax the smooth muscle fibers in the prostate and the neck of the bladder (the part of the bladder that opens into the urethra). Muscle relaxation helps open up more space for urine to flow along the urethra and results in a stronger urine flow.
The alpha blockers are just as likely to be effective for any men with BPH, not just those with larger prostates. However, not all men find them to be completely effective in relieving urinary symptoms. In addition, the alpha blockers may lower blood pressure, a disadvantage for men who don’t need this effect. The side effects of alpha blockers can include dizziness, excessive drops in blood pressure, swelling of the ankles, and drowsiness.
The alpha-blocking drugs tamsulosin and alfuzosin act more specifically on the prostate. Because they are less likely to lower blood pressure, they may be safer for men who are already taking blood pressure medication or who have heart disease. Unfortunately, their prostate-specific action also makes them more likely to cause retrograde ejaculation, a side effect that may be reversible after the drugs are stopped.
Combination Therapy
Because the 5-alpha-reductase inhibitors and the alpha blockers act so differently to treat BPH, and act on such different timetables, doctors have tried prescribing both types of drugs at once. Although it is possible for a doctor to combine either 5-alpha-reductase inhibitor with any of the 4-alpha blockers, so far the best-tested combination is finasteride and doxazosin.
A long-term study of 3,047 men sponsored by the National Institutes of Health showed that combination therapy with finasteride and doxazosin together is an effective strategy for treating LUTS due to BPH. Taking both finasteride and doxazosin together was more effective in relieving urinary symptoms, preventing urinary retention, and preventing the progression of BPH than taking either drug alone. The availability of combination therapy provides an important new alternative to men who otherwise might have to consider surgical options sooner.