Prazosin comes as a tablet and capsule to take by mouth. It usually is taken three times a day at evenly spaced intervals. The first time taking prazosin, you should take it before you go to bed. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take prazosin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Prazosin controls high blood pressure, but does not cure it. Continue to take prazosin even if you feel well. Do not stop taking prazosin without talking to your doctor.

Although side effects from prazosin are not common, they can occur. Tell your doctor if any of these symptoms are severe or do not go away:

dizziness
drowsiness
weakness
tiredness
headache
upset stomach
If you experience any of the following symptoms, call your doctor immediately:

difficulty breathing
fast heartbeat
irregular heartbeat
chest pain
fainting

Your doctor may prescribe a low-salt or low-sodium diet. Follow these directions carefully.

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Keep all appointments with your doctor and the laboratory. Your blood pressure should be checked regularly to determine your response to prazosin.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one. Check with your doctor if you have missed two or more doses.

Prazosin is used to treat high blood pressure. It works by relaxing the blood vessels so that blood can flow more easily through the body.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information

Prazosin also is used to treat benign prostatic hyperplasia (BPH), congestive heart failure, and Raynaud's disease. Talk to your doctor about the possible risks of using this drug for your condition.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

Before taking prazosin,

tell your doctor and pharmacist if you are allergic to prazosin, doxazosin (Cardura), terazosin (Hytrin), or any other drugs.
tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially beta blockers such as atenolol (Tenormin), carteolol (Cartrol), labetalol (Normodyne,Trandate), metoprolol (Lopressor), nadolol (Corgard), propranolol (Inderal), sotalol (Betapace), and timolol (Blocadren); clonidine (Catapres); indomethacin (Indocin); verapamil (Calan); and vitamins.
tell your doctor if you have or have ever had liver disease.
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking prazosin, call your doctor.
if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking prazosin.
you should know that this drug may make you drowsy or dizzy. Do not drive a car or operate machinery for 12-24 hours after the first time you take prazosin or after your dose is increased.