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Medications and Drugs

Brand Names: Wytensin

Generic Name: guanabenz (Pronunciation: GWAN a benz)

What is guanabenz (Wytensin)?

Guanabenz lowers blood pressure by decreasing the levels of certain chemicals in the blood. This allows the blood vessels (veins and arteries) to relax (widen).

Guanabenz is used to treat hypertension (high blood pressure).

Guanabenz may also be used for purposes other than those listed in this medication guide.

Guanabenz 4 mg-IVA

round, peach, imprinted with 4226, Z

Guanabenz 8 mg-IVA

round, gray, imprinted with 4227, Z

What are the possible side effects of guanabenz (Wytensin)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

  • very slow heart rate;
  • chest pain, severe headache, ringing in your ears; or
  • feeling like you might pass out.

Less serious side effects may include:

  • dizziness, drowsiness;
  • headache;
  • dry mouth; or
  • weakness.

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 FDA at 1-800-FDA-1088. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about guanabenz (Wytensin)?

Do not stop taking this medication without first talking to your doctor. Stopping suddenly may make your condition worse.

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

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.

Keep using this medicine as directed, 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.

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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