Terazosin

Pronunciation: ter-ay-zo-sin
Generic name: terazosin
Brand names: Hytrin (discontinued), Tezruly
Dosage form: oral capsule, oral solution
Drug classes: Alpha blockers, Antiadrenergic agents, peripherally acting

Medically reviewed by Carmen Pope, BPharm. Last updated on Jul 31, 2024.

What is terazosin?

Terazosin is in a group of drugs called alpha-adrenergic blockers. Terazosin relaxes your veins and arteries so that blood can more easily pass through them. It also relaxes the muscles in the prostate and bladder neck, making it easier to urinate.

Terazosin is used to treat hypertension (high blood pressure) or to improve urination in men with benign prostatic hyperplasia (enlarged prostate).

Terazosin may also be used for other purposes not listed in this medication guide.

Terazosin is available as generic terazosin capsules and as Tezruly oral solution. The brand Hytrin (oral tablet) has been discontinued in the United States but may be available in other countries. Hytrin gained FDA approval on August 7, 1994, and Tezruly gained FDA approval on July 29, 2024.

Terazosin side effects

The most common side effects of terazosin include:

weakness
puffy feet or hands
nasal congestion
dizziness
lack of energy
drowsiness.

Serious side effects and warnings

Terazosin may cause the following serious side effects.

A sudden drop in blood pressure, especially when you first start treatment or when there is an increase
in your dose of terazosin, is common but can also be serious. This may cause you to have a feeling that
your heart is pounding or racing (palpitations), faint, have a spinning feeling (vertigo), or feel dizzy or
lightheaded.

If you have a spinning feeling, dizziness, or lightheadedness, you should sit or lie down and
be careful when rising from a sitting or lying position.
Your risk of having this problem may be increased if you take terazosin with certain other medicines that lower blood pressure including verapamil and PDE-5 inhibitors, such as sildenafil or tadalafil. Your healthcare provider may monitor your blood pressure while you take terazosin.

A painful erection that will not go away. Terazosin can cause a painful erection (priapism), which cannot be relieved by having sex or masturbation. If this happens, get medical help right away. If priapism is not treated, you may not be able to get an erection in the future.

Eye problems during cataract surgery. A condition called Intraoperative Floppy Iris Syndrome (IFIS)
can happen during cataract surgery if you take or have taken alpha-blockers such as terazosin. If you
need to have cataract surgery, be sure to tell your ophthalmologist (eye doctor) if you take or have taken
terazosin

There is a risk of allergic reactions with terazosin. Do not take terazosin if you are allergic to terazosin or any of the inactive ingredients in the terazosin formulation you are taking (such as generic terazosin, Hytrin, or Tezruly). Get emergency medical help if you have any of these signs of an allergic reaction such as difficulty breathing, or swelling of your face, lips, tongue, or throat.

It is not known if terazosin is safe and effective in children.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Before taking

You should not use this medication if you are allergic to terazosin or any of the inactive ingredients in the formulation.

Before taking terazosin, tell your healthcare provider about all of your medical conditions, including
if you:

have had low blood pressure, especially after taking other medicines. Signs of low blood pressure include
fainting, dizziness, and lightheadedness
have any planned eye surgery
have prostate cancer, or a history of prostate cancer. Your healthcare provider may have you checked for
prostate cancer before you start taking and while you take terazosin
are pregnant or plan to become pregnant. It is not known if terazosin will harm your unborn baby
are breastfeeding or plan to breastfeed. It is not known if terazosin passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby if you take terazosin.

How should I take terazosin?

Take terazosin exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Take terazosin once a day by mouth
The starting dose is 1mg.
- Terazosin may be taken as a 1mg terazosin generic capsule or 1 mL of Tezruly 1 mg/mL solution.
Terazosin may be taken with or without food.

Terazosin lowers blood pressure and may cause dizziness or fainting, especially when you first start taking it, or when you start taking it again.

Do not take more than 1 mg as your starting dose.
You may wish to take this medication only at bedtime if it causes you to feel light-headed. Call your doctor if you have severe dizziness or feel like you might pass out.
You may feel very dizzy when you first wake up. Be careful when standing or sitting up from a lying position.

Take Tezruly oral solution using a marked (calibrated) measuring device, such as an oral syringe or oral dosing cup. Ask your pharmacist for a measuring device and instructions on how to measure and take the correct dose of medicine. A household measuring cup, teaspoon, or tablespoon is not an adequate measuring
device.

Your blood pressure or prostate will need to be checked often. Visit your doctor regularly.

If you are being treated for high blood pressure, keep using terazosin even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

Some things can cause your blood pressure to get too low. This includes vomiting, diarrhea, heavy sweating, heart disease, dialysis, a low-salt diet, or taking diuretics (water pills). Tell your doctor if you have a prolonged illness that causes diarrhea or vomiting.

Call your doctor at once if you have any of these serious side effects:

fast or pounding heartbeats or fluttering in your chest;
feeling like you might pass out;
swelling in your hands, ankles, or feet; or
penis erection that is painful or lasts 4 hours or longer.

Terazosin dosing information

Usual Terazosin Adult Dose for Hypertension:

Initial dose: 1 mg orally once a day at bedtime

Maintenance dose: 1-5 mg orally once a day.

If the response is diminished at 24 hours, increase the dose or use twice daily.

Maximum dose: 20 mg per day.

Usual Terazosin Adult Dose for Benign Prostatic Hyperplasia:

Initial dose: 1 mg orally once a day at bedtime.

Maintenance dose: Increase the dose in a stepwise fashion to 2 mg, 5 mg, or 10 mg once a day to achieve desired improvement of symptoms. Generally, dosages of 10 mg/day are needed for a clinical response.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up for the missed dose.

If you miss your doses for several days in a row, contact your doctor before restarting the medication. You may need a lower dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include extreme dizziness or fainting.

What should I avoid?

Do not drive or perform any hazardous task until at least 12 hours after you have taken terazosin if you are
taking:

your first dose of terazosin
terazosin for the first time after your healthcare provider has increased your dose of it
terazosin for the first time after any breaks (interruptions) in your treatment with terazosin.

Terazosin may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert. You may wish to take this medication only at bedtime if it causes you to feel light-headed.

To prevent dizziness, avoid standing for long periods or becoming overheated during exercise and in hot weather.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall. Drinking alcohol can increase certain side effects of terazosin.

What other drugs will affect terazosin?

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Terazosin may affect the way other medicines work,
and other medicines may affect the way terazosin works causing side effects. Especially tell your healthcare provider if you take:

other medicines for high blood pressure, particularly the calcium channel blocker verapamil. The use of
terazosin with verapamil can lead to a drop in blood pressure or to fainting
medicines to treat erectile dysfunction (ED) called phosphodiesterase type 5 (PDE-5) inhibitors, such as sildenafil (Viagra, Revatio), tadalafil (Cialis), or vardenafil (Levitra). The use of terazosin with PDE-5 inhibitors can lead to a drop in blood pressure or to fainting.

Know your medicines. Keep a list to show your healthcare providers or pharmacist when you get a new
medicine. See the terazosin prescribing information for a full list of interactions.

Storage

Store terazosin at room temperature away from moisture, heat, and light.

Tezruly ingredients

Tezruly active ingredient: terazosin hydrochloride 1 mg/mL.

Tezruly inactive ingredients: artificial cherry flavor, citric acid anhydrous, glycerin, methylparaben, propylparaben, purified water, sodium citrate dihydrate, and sucralose.