Guanfacine (By mouth)

Introduction

Guanfacine (GWAHN-fa-seen)

Treats high blood pressure. Also used alone or together with other medicines to treat attention deficit hyperactivity disorder (ADHD).

Brand Name(s)

Tenex, Intuniv

There may be other brand names for this medicine.

When This Medicine Should Not Be Used

You should not use this medicine if you have had an allergic reaction to guanfacine or to other products containing guanfacine (such as Intuniv® or Tenex®).

How to Use This Medicine

Tablet, Long Acting Tablet

  • Your doctor will tell you how much of this medicine to use and how often. Your dose may need to be changed several times in order to find out what works best for you. Do not use more medicine or use it more often than your doctor tells you to.
  • Take this medicine exactly as your doctor ordered. Even if you feel fine your blood pressure can still be high.
  • You may take this medicine with or without food.
  • If you are taking guanfacine once a day, take the dose at bedtime to avoid being drowsy during the day (unless your doctor tells you differently).
  • The extended-release form of this medicine is taken once a day, usually in the morning. It should not be taken with high fat meals.
  • Swallow the extended-release tablet whole. Do not crush, break, or chew it.
  • This medicine is part of an ADHD treatment program that may also include counseling or special education. Carefully follow your doctor's instructions about all treatment measures.
  • Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way.
  • This medicine comes with patient instructions. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions.

If a dose is missed:

  • If you miss a dose or forget to use your medicine, use it as soon as you can. If it is almost time for your next dose, wait until then to use the medicine and skip the missed dose. Do not use extra medicine to make up for a missed dose.
  • If you miss taking guanfacine extended-release tablets for two or more days in a row, check with your doctor.

How to Store and Dispose of This Medicine

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
  • Keep all medicine away from children and never share your medicine with anyone.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Do not use this medicine if you or your child are also using other products containing guanfacine (such as Intuniv® or Tenex®).
  • Make sure your doctor knows if you are also using ketoconazole (Nizoral®), rifampicin (Rifadin®, Rimactane®), medicine to lower blood pressure (such as atenolol, hydrochlorothiazide [HCTZ], lisinopril, metoprolol, quinapril, Accupril®, Cozaar®, Diovan®, Lotrel®, Norvasc®, Toprol®, or Zestril®), a benzodiazepine medicine (such as diazepam, lorazepam, Ativan®, or Valium®), medicine for seizures (such as phenobarbital, valproic acid, Depakene®, or Luminal®), or a phenothiazine medicine (such as prochlorperazine, Compazine®, Mellaril®, Phenergan®, Thorazine®, or Trilafon®).
  • Do not drink alcohol while you are using this medicine.
  • Tell your doctor if you are using any medicines that make you sleepy. These include sleeping pills, cold and allergy medicine, narcotic pain relievers, and sedatives.

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, or depression. Tell your doctor if you have a history of heart or blood vessel disease, heart block, fainting, low blood pressure, slow heart rate, or a recent heart attack or stroke.
  • Do not stop using this medicine suddenly without asking your doctor. You may need to slowly decrease your dose before stopping it completely.
  • Make sure any doctor or dentist who treats you knows that you are using this medicine. You may need to stop using this medicine several days before having surgery or medical tests.
  • This medicine may make you dizzy, drowsy, faint, or lightheaded. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert. Change positions slowly when getting up from a sitting or lying position.
  • Your doctor will need to check your progress at regular visits while you are using this medicine. Be sure to keep all appointments. Blood tests may be needed to check for unwanted effects.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Chest pain.
  • Lightheadedness, dizziness, or fainting.
  • Severe weakness.
  • Slow or uneven heartbeat.
  • Trouble with breathing.
  • Unusual drowsiness or sleepiness.
  • Unusual tiredness or weakness.

If you notice these less serious side effects, talk with your doctor:

  • Constipation, diarrhea, nausea, vomiting, or stomach pain.
  • Decreased appetite.
  • Dry mouth and nose.
  • Feeling depressed or irritable.
  • Headache or eye irritation.
  • Trouble having sex.
  • Trouble sleeping.
  • Weight gain.

If you notice other side effects that you think are caused by this medicine, tell your doctor

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

Version Info

  • Last Reviewed on 06/12/2013

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This page was last updated: June 18, 2013

         
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