Alpha-blockers for benign prostatic hyperplasia

Examples

Alpha-blocker medications approved by Health Canada 's Therapeutic Products Directorate (TPD) for the treatment of benign prostatic hyperplasia (BPH) and high blood pressure:

Generic Name	Brand Name
doxazosin mesylate	Cardura
terazosin hydrochloride	Hytrin

A TPD-approved alpha-blocker for the treatment of BPH:

Generic Name	Brand Name
alfuzosin hydrochloride	Xatral
tamsulosin hydrochloride	Flomax

An alpha-blocker medication that can be used, but has not been recommended, to treat BPH and is normally used to treat high blood pressure:

Generic Name	Brand Name
prazosin hydrochloride	Minipress

How It Works

Alpha-blockers help treat benign prostatic hyperplasia (BPH) by relaxing smooth muscle tissue found in the prostate and the bladder neck. This allows urine to flow out of the bladder more easily.

These medications usually are taken by mouth once or twice a day. Except for alfuzosin and tamsulosin, they also are used to treat high blood pressure.

Why It Is Used

These medications often are used by men who have moderate and bothersome symptoms of prostate enlargement and who want more than home treatment for their symptoms.

How Well It Works

Many men find a 4- to 6-point reduction in their International Prostate Symptom Score (I-PSS). Most men find this a significant improvement in their symptoms.¹ Symptoms generally improve in 2 to 3 weeks.²

A U.S. National Institutes of Health (NIH) study found that combining finasteride with the alpha-blocker doxazosin (Cardura) reduces the chances of symptoms getting worse, urinary retention, and the need to have surgery. The combination of the two medicines worked better than either medicine alone or when compared with a placebo.³

Side Effects

Side effects vary with the medication and individual. Common minor side effects of alpha-blockers include:

• Weakness or fatigue.
• Light-headedness, dizziness, or fainting when you stand up suddenly after sitting or lying down. This may occur if your blood pressure becomes low when you stand up suddenly (postural or orthostatic hypotension).
• Headaches and nasal congestion.

Medicines used to treat erection problems, such as sildenafil (Viagra), vardenafil (Levitra), or tadalafil (Cialis), may make these side effects worse.

Alpha-blockers may cause ejaculation back into the bladder (retrograde ejaculation). This is not harmful.

These side effects go away when the medication is stopped.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Some evidence suggests that alpha-blockers are more effective than finasteride in relieving symptoms.⁴

Long-acting forms of these medications can be taken once a day, which may make them more convenient to take than finasteride.

Fewer side effects, especially low blood pressure when standing up suddenly, may occur if the drug is taken at bedtime.

Alpha-blockers are also used to treat high blood pressure (hypertension). Some of these drugs can be used to treat both high blood pressure and benign prostatic hyperplasia (BPH) in men who have both conditions.

• When using terazosin, some decrease in blood pressure may be expected in men with or without high blood pressure. However, the blood pressure decrease in men who do not have high blood pressure usually is not significant and generally does not cause any problems.
• Doxazosin lowers blood pressure; however, it may not be effective in preventing heart failure in people with high blood pressure who are at high risk for developing heart failure. In a recent study of people ages 55 and older with high blood pressure and a high risk for heart problems, the use of doxazosin was discontinued because of the high number of people experiencing heart failure who were using that medication.⁵ It may be a suitable medication choice for BPH symptoms if you do not have a risk of heart failure.

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Author:	Douglas Dana Ralph Poore	Last Updated: August 30, 2006
Medical Review:	Martin Gabica, MD - Family Medicine Adam Husney, MD - Family Medicine J. Curtis Nickel, MD, FRCSC - Urology Christopher G. Wood, MD, FACS - Urology/Oncology
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