SIDE EFFECTS: Fatigue, nausea, drowsiness, blurred vision, headache, or stuffy nose may occur. Lightheadedness or dizziness upon standing may also occur, especially after the first dose, and shortly after taking the drug during the first week of treatment. To minimize dizziness and the risk of fainting, get up slowly when rising from a seated or lying position. If dizziness occurs, sit or lie down. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: fainting, fast/irregular heartbeat, burning/tingling in the hands/feet, sexual function problems, swelling of the ankles/hands/feet, unexpected weight gain.

Tell your doctor immediately if any of these rare but serious side effects occur: easy bruising/bleeding, mental/mood changes.

For males, in the very unlikely event you have a painful or prolonged erection lasting 4 or more hours, stop using this drug and seek immediate medical attention, or permanent problems could occur.

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Read the Hytrin (terazosin hcl) Side Effects Center for a complete guide to possible side effects »

PRECAUTIONS: Before taking terazosin, tell your doctor or pharmacist if you are allergic to it; or to other alpha-blockers (e.g., doxazosin, prazosin); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: low blood pressure/fainting, prostate cancer, other prostate/bladder problems, liver disease.

This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. You should avoid driving or hazardous tasks for 12 hours after the first dose, after your dose is increased, and when this medication is restarted after it has been stopped. Limit alcoholic beverages.

To reduce the risk of dizziness and fainting, caution is advised when standing for long periods. Avoid getting overheated during exercise or hot weather. If dizziness occurs, sit or lie down.

Before having surgery (including cataract eye surgery), tell your doctor or dentist that you are taking this medication.

Caution is advised when using this drug in the elderly because they may be more sensitive to its effects, especially dizziness and fainting.

This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor.

It is not known whether this drug passes into breast milk. Consult your doctor before breast-feeding.