Tenex

Generic name: guanfacine (oral route)
Drug class: Antiadrenergic agents, centrally acting

Medically reviewed by  A Ras MD

What is Tenex?

Tenex is a prescription medication that is used to treat high blood pressure.

Tenex may be given to you for other reasons. Talk to your doctor.

Description

Tenex (guanfacine hydrochloride) is a centrally acting antihypertensive with α2-adrenoceptor agonist properties in tablet form for oral administration.

The chemical name of Tenex (guanfacine hydrochloride) is N-amidino- 2-(2,6-dichlorophenyl) acetamide hydrochloride and its molecular weight is 282.56. Its structural formula is:

Guanfacine hydrochloride is a white to off-white powder; sparingly soluble in water and alcohol and slightly soluble in acetone. The tablets contain the following inactive ingredients:

• 1 mg—FD&C Red 40 aluminum lake, lactose, microcrystalline cellulose, povidone, stearic acid.
• 2 mg—D&C Yellow 10 aluminum lake, lactose, microcrystalline cellulose, povidone, stearic acid.

Before taking Tenex, tell your doctor:

• If you are allergic to Tenex; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.

This is not a list of all drugs or health problems that interact with this medicine.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take Tenex with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Tenex?

• Tell all of your health care providers that you take Tenex. This includes your doctors, nurses, pharmacists, and dentists.
• Avoid driving and doing other tasks or actions that call for you to be alert until you see how Tenex affects you.
• To lower the chance of feeling dizzy or passing out, rise slowly if you have been sitting or lying down. Be careful going up and down stairs.
• Check blood pressure and heart rate as the doctor has told you.
• Avoid drinking alcohol while taking Tenex.
• Talk with your doctor before you use other drugs and natural products that slow your actions.
• If you are taking Tenex and have high blood pressure, talk with your doctor before using OTC products that may raise blood pressure. These include cough or cold drugs, diet pills, stimulants, ibuprofen or like products, and some natural products or aids.
• Tell your doctor if you have too much sweat, fluid loss, throwing up, or loose stools. This may lead to low blood pressure.
• Be careful in hot weather or while being active. Drink lots of fluids to stop fluid loss.
• Do not stop taking Tenex all of a sudden without calling your doctor. High blood pressure and fast heartbeat can happen if Tenex is stopped all of a sudden. Other signs of withdrawal like headache, shakiness, or feeling agitated, confused, or nervous can also happen. If these get worse and are not treated, it could lead to a very bad health problem with signs like feeling very sleepy or tired, very bad headache, throwing up, change in eyesight, or seizures. If you need to stop Tenex, you will want to slowly stop it as ordered by your doctor.
• Tell your doctor if you have been throwing up and cannot take Tenex.
• If your doctor has told you to lower your dose or slowly stop taking Tenex, you will need to check your blood pressure and heart rate closely. Follow what your doctor has told you to do.
• Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.

How is Tenex best taken?

Use Tenex as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• Take Tenex at bedtime.
• Keep taking Tenex as you have been told by your doctor or other health care provider, even if you feel well.

What do I do if I miss a dose?

• Take a missed dose as soon as you think about it.
• If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
• Do not take 2 doses at the same time or extra doses.

What are the side effects of Tenex that I need to call my doctor about immediately?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Very bad dizziness or passing out.
• Slow heartbeat.
• A heartbeat that does not feel normal.
• Not able to get or keep an erection.

What are some other side effects of Tenex?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Feeling dizzy, sleepy, tired, or weak.
• Dry mouth.
• Headache.
• Constipation.
• Upset stomach.
• Stomach pain.
• Trouble sleeping.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

Label

PRINCIPAL DISPLAY PANEL

PRINCIPAL DISPLAY PANEL

If overdose is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Tenex?

• Store at room temperature.
• Store in a dry place. Do not store in a bathroom.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

SRC: NLM .