In this session, we will be discussing the consumer medication information for guanfacine, trade name TenexTM.

What it’s for & How to take

Guanfacine works in your brain to relax pressure on your blood vessels. This medication is used to treat high blood pressure. Guanfacine is also used for the treatment of other conditions not listed here. If you are using this medication for something other than high blood pressure, please discuss this with your doctor or pharmacist.

Guanfacine is also available in an extended-release tablet under the trade name of IntunivTM and is used to treat attention deficit hyperactivity disorder. Guanfacine ER will be reviewed in a separate session.

If high blood pressure is not treated, your blood vessels will harden, and this will eventually lead to a heart attack or a stroke. High blood pressure may also cause vision problems, kidney failure and eventually heart failure.

Guanfacine is usually taken once daily at bedtime or as directed by your doctor. You may take this medication with or without food. Take guanfacine at the same time each day with a full glass of water.

If you forget to take a dose, take it as soon as you remember. If it is near the time of your next dose, skip it and continue with your normal dose time. Do not take a double dose to make up the missed dose.

Keep using this medication, even if you don’t feel sick. You may need to treat your high blood pressure for many years.

Your blood pressure should be checked often to make sure the medication is working correctly.

Warnings & Cautions

  • Do not stop guanfacine or decrease the dose unless your doctor tells you to do so. If you stop this medication quickly, you may feel nervous and shaky. Your blood pressure may increase very quickly if this medication is stopped too quickly.
  • If you need to stop this medication, your doctor may slowly decrease your dose over 1-2 weeks to decrease the chance of heart problems.
  • Blood pressure medication may make you feel light-headed or dizzy. Take it slow when you go from a sitting to standing position. Balance yourself to make sure you are stable before taking a step.
  • The elderly may be more sensitive to the side effects of this medication, especially the drowsiness and dizziness. The chance of loss of balance and falling are increased.
  • Let your pharmacist or doctor know if you are pregnant or breastfeeding before taking this medication.
  • This medication may make you dizzy, drowsy, or blur your vision. Do not drive or do any activity that requires focus and attention until you are sure you can do them safely. Avoid alcoholic beverages while taking guanfacine.

Interactions & Side Effects

  • Tell your pharmacist or doctor all your medication allergies so they may determine if guanfacine is safe for you to take.
  • Avoid dangerous drug interactions. Tell your pharmacist or doctor all the other medication you are taking, including over the counter supplements, even if you don’t take them very often.
  • Ask your doctor if this medication is safe to take with your current health conditions. Tell your doctor if you have any history of heart rhythm problems, liver or kidney disease, diabetes, any circulation problems, or any mental/mood issues.
  • While taking this medication, you may feel some drowsiness, constipation and possibly a dry mouth. If these or any other unwanted side effects persist, contact your doctor or pharmacist to talk about it with them.
  • Call your doctor right away if you feel severe dizziness or fainting, very slow heartbeat, or any big mood changes such as depression or agitation.
  • Call emergency 911 if you have any symptoms of a heart attack such as chest and left arm pain, shortness of breath and sweating or if you have symptoms of a stroke such as weakness on one side of your body, slurred speech, sudden vision changes, and confusion.

If you have any questions about what you have heard, contact your pharmacist or doctor. This session does not include all the potential interactions or side effects that this medication may cause. Ask your pharmacist how your medication should be stored and how you should dispose of it when you are done taking it. Do not share your medication with anyone, ever. Remember, this is not meant to replace your counseling session with your pharmacist. In case of overdose, call your local poison control center at 1-800-222-1222.

Updated 7/20