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Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Limited Use [what does this mean?]
Generic drug name: alfuzosin (al FOO zoe sin)
Brand name(s): UROXATRAL
GENERIC: available FAMILY: Alpha Blockers
Find the drug label by searching at DailyMed.

Limited Use [what does this mean?]
Generic drug name: doxazosin [prostate] (DOX a zoe sin)
Brand name(s): CARDURA [PROSTATE], ZONALON
GENERIC: available FAMILY: Alpha Blockers
Find the drug label by searching at DailyMed.

Limited Use [what does this mean?]
Generic drug name: tamsulosin (tam SOO loh sin)
Brand name(s): FLOMAX, JALYN
GENERIC: available FAMILY: Alpha Blockers
Find the drug label by searching at DailyMed.

Limited Use [what does this mean?]
Generic drug name: terazosin [prostate] (ter AY zoe sin)
Brand name(s): HYTRIN [PROSTATE]
GENERIC: available FAMILY: Alpha Blockers
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Breast-feeding Warning

For women who take the alpha-blockers doxazosin or terazosin to lower blood pressure:

Doxazosin accumulates in rat breast milk to a concentration 20 times greater than the level in maternal plasma. Because of the potential for serious adverse effects to the fetus, these drugs should not be used by pregnant women.

Safety Warnings For This Drug [top]

We have listed these alpha-blockers as Do Not Use drugs for the treatment of high blood pressure.

Blood-Pressure-Lowering Effects

The alpha-blocking drugs can cause a sudden drop in blood pressure, especially in the upright position, that can lead to dizziness and fainting. These adverse effects are most common with the first dose but can also occur when there is a dosage increase, or if treatment is interrupted for more than a few days. To decrease the likelihood of excessive blood pressure lowering, it is essential that treatment be started with a low dose.

Facts About This Drug [top]

The alpha-blocker family includes six drugs: alfuzosin (UROXATRAL), doxazosin (CARDURA), prazosin (MINIPRESS), silodosin (RAPAFLO), tamsulosin (FLOMAX) and terazosin (HYTRIN). Three of these drugs — doxazosin, prazosin, and terazosin — are approved by the Food and Drug Administration (FDA) to treat high blood pressure. Five of these drugs are approved by the FDA to treat benign prostatic hyperplasia (BPH), or enlarged prostate gland: alfuzosin, doxazosin, silodosin, tamsulosin and terazosin.

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The alpha-blocker family includes six drugs: alfuzosin (UROXATRAL), doxazosin (CARDURA), prazosin (MINIPRESS), silodosin (RAPAFLO), tamsulosin (FLOMAX) and terazosin (HYTRIN). Three of these drugs — doxazosin, prazosin, and terazosin — are approved by the Food and Drug Administration (FDA) to treat high blood pressure. Five of these drugs are approved by the FDA to treat benign prostatic hyperplasia (BPH), or enlarged prostate gland: alfuzosin, doxazosin, silodosin, tamsulosin and terazosin.

Enlargement of the prostate gland impedes urination, causing a weak stream, double voiding, inability to empty the bladder completely and urinary tract infections. BPH affects 50% of men over age 60 and 90% of men in their seventies and eighties.[1]

Terazosin and doxazosin are approved to treat both high blood pressure and enlarged prostate but should not be used to treat high blood pressure. Public Citizen lists them as Do Not Use drugs for this treatment.

Alpha-blockers relieve the symptoms of BPH by relaxing smooth muscle in the prostate. All alpha-blockers appear to be similarly effective in relieving the symptoms of BPH.[1]

For patients with minimal symptoms of BPH, no treatment is necessary, no matter the size of the prostate gland. For patients who have BPH symptoms and do not have a very enlarged gland, an alpha-blocker such as terazosin would be the best choice. In patients with very enlarged prostates, treatment with an alpha-blocker would, again, be the best choice.

Adverse effects

All alpha-blockers increase the risk of hypotension (low blood pressure), postural hypotension (low blood pressure when standing up) and syncope (fainting). This risk is highest when first starting these drugs. Taking alpha-blockers along with antihypertensive medication or nitrates also increases the risk of hypotension. Other adverse effects commonly seen with alpha blockers are headache and dizziness.

In 2015 an article published in the British Medical Journal (BMJ) showed that alpha-blocker drugs increased the risk of falls, fractures and head trauma in men aged 66 or older.[2]

Alfuzosin differs from the other drugs in this family in that it must not be used in people with moderate-to-severe liver problems. In addition, alfuzosin must not be used together with ketoconazole (NIZORAL), itraconazole (SPORANOX) or ritonavir (NORVIR) because blood levels of alfuzosin will be increased, increasing the risk of hypotension and other adverse effects.[3]

Alfuzosin can cause an adverse effect in the heart known as QT interval prolongation, a change in the electrical activity of the heart that can lead to a fatal heart rhythm disturbance called torsades de pointes, resulting in sudden death.[3]

Men with a known history of QT prolongation or who are using other drugs known to prolong the QT interval should not take alfuzosin. The Arizona Health Sciences Center maintains an extensive list of drugs that prolong QT intervals at www.torsades.org.

A surgical condition termed Intraoperative Floppy Iris Syndrome (IFIS) has been observed during cataract surgery in some patients currently taking or previously treated with alpha-blockers.[3],[4],[5],[6] Most of these reports were in patients taking an alpha-blocker when IFIS occurred, but in some cases, an alpha-blocker had been stopped prior to surgery. If you are scheduled to have cataract surgery and are taking tamsulosin or any other alpha-blocker, make sure to tell your doctor.[7]

A study published in the Journal of the American Medical Association reported that men aged 66 or older who used tamsulosin either at the time of the study or prior to it had a risk of serious eye complications after cataract surgery.[8]

MEDSAFE, an agency in New Zealand similar to the FDA, issued an advisory in April 2014 that the Center for Adverse Reaction Monitoring had received seven reports of nightmares associated with doxazosin therapy since 1992.[9]

In 2018, Pharmacoepidemiology and Drug Safety published a study suggesting that tamsulosin was associated with an increased risk of dementia in older men with BPH.[10]

Before You Use This Drug [top]

Do not use if you have or have had allergies to the drug or any component of the capsule or tablet.

Tell your doctor if you have or have had:

  • angina (chest pain)
  • high blood pressure (symptomatic)
  • previous low blood pressure from other drugs
  • heart problems
  • history of prolonged QTc intervals
  • kidney problems
  • prostate cancer
  • liver problems

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.

When You Use This Drug [top]

  • Avoid alcohol.
  • Try to have a companion stay with you for a few hours when you take your first dose. Move any object that would be dangerous if you fell onto it, during day or night. This includes unanchored rugs. Change positions gradually. If you are lying down, hang your legs over the side of the bed for a few minutes, then get up slowly. When getting up from a chair, stay by the chair until you are sure that you are not dizzy, especially after the first dose. If you become dizzy, sit or lie down.
  • Do not drive or operate hazardous equipment until you know whether or not you become drowsy or dizzy when using an alpha-blocker, especially for the first 24 hours after the first dose, whenever a dose is increased, or when use is resumed after interruption of therapy.
  • Take your blood pressure periodically.
  • Tell any doctor, dentist, emergency help, pharmacist, or surgeon you see that you use an alpha-blocker.
  • Rule out the presence of prostate cancer before starting the drug.
  • It may take two to six weeks before you experience improvement in symptoms.

How to Use This Drug [top]

  • If you miss a dose, take it as soon as you remember, but skip it if it is almost time for the next dose. Do not take double doses.
  • Do not share your medication with others.
  • Take the drug at the same time(s) each day. If you are prescribed more than one dose per day, space the doses at equal intervals.
  • Swallow alfuzosin tablet(s) whole, with food, and with the same meal each day. Do not chew or crush.
  • Swallow doxazosin tablets in the morning or evening.
  • Swallow tamsulosin capsule(s) whole about 30 minutes after the same meal each day, usually breakfast. Do not chew, crush, or open capsules.
  • Swallow terazosin capsule(s) at bedtime.
  • Store capsules or tablets at room temperature with lid on tightly. Do not expose to heat, moisture, or strong light. Keep out of reach of children.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

amlodipine, bepridil, CALAN, CARDENE, CARDIZEM, cimetidine, DIBENZYLINE, diltiazem, DYNACIRC, felodipine, ISOPTIN, isradipine, moxisylyte, nicardipine, nifedipine, nimodipine, NIMOTOP, nisoldipine, NORVASC, phenoxybenzamine, phentolamine, PLENDIL, PROCARDIA, REGITINE, SULAR, TAGAMET, VASCOR, verapamil.

For alfuzosin: itraconazole, ketoconazole, NIZORAL, NORVIR, ritonavir, SPORANOX.

Adverse Effects [top]

Call your doctor immediately if you experience:

  • blood pressure decrease
  • difficulty breathing
  • chest pain
  • dizziness, lightheadedness, or fainting
  • headache
  • difficulty sleeping
  • painful or prolonged erection
  • fast, irregular, or pounding heartbeat
  • numbness or tingling of hands and feet
  • skin itching, rash, or spots
  • swelling of ankles or feet
  • swelling of tongue, lips, neck, or face
  • uncontrollable urination
  • unusual weakness or tiredness
  • drowsiness
  • back pain
  • diarrhea
  • nausea
  • stuffy or runny nose
  • abnormal ejaculation

Call your doctor if these symptoms continue:

  • wheezing
  • constipation
  • diarrhea
  • belching
  • tenderness around eyes
  • trouble swallowing
  • voice changes
  • heartburn
  • tightness in chest
  • drowsiness, fatigue, sleepiness
  • dry cough or cough producing mucus
  • dry mouth
  • ringing in ears
  • sore gums or throat
  • headache
  • joint pain
  • hoarseness
  • nasal congestion
  • nausea or vomiting
  • indigestion
  • nervousness, restlessness, or irritability
  • pain in joints, arms, back, or legs
  • sexual dysfunction, such as diminished ejaculation (especially tamsulosin) or impotence
  • blurred vision
  • undesired weight gain (especially with doxazosin and terazosin)
  • abdominal pain
  • fever

Signs of overdose:

  • profound drowsiness
  • severe headache
  • decreased heart rate
  • depressed reflexes
  • low blood pressure
  • seizures

If you suspect an overdose, call this number to contact your poison control center: (800) 222-1222.

Periodic Tests[top]

Ask your doctor which of these tests should be done periodically while you are taking this drug:

  • blood pressure
  • digital rectal exam
  • peak urinary flow rate
  • PSA (prostate-specific antigen)
  • questionnaires on symptom relief

last reviewed May 31, 2021