Tenormin treats high blood pressure and other heart conditions. Do not stop taking this medication without talking to your doctor first.

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Pharmacist, Anyssa S. Garza, PharmD, overviews the uses and common side effects of Tenormin.
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Pharmacist, Anyssa S. Garza, PharmD, overviews the uses and common side effects of Tenormin.
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Tenormin Overview


Tenormin is a prescription medication used to treat high blood pressure (hypertension), to prevent angina (chest pain), and to improve survival after a heart attack. Tenormin belongs to a group of drugs called beta blockers, which relax blood vessels and reduce heart rate.

This medication comes in tablet form and is taken once or twice a day, with or without food. Tenormin is also available in an injectable form to be given directly into a vein (IV) by a healthcare professional.

Common side effects include tiredness, nausea, and dizziness. Do not drive or operate heavy machinery until you know how Tenormin affects you.

Patient Ratings for Tenormin

How was your experience with Tenormin?

First, a little about yourself

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What tips would you provide a friend before taking Tenormin?

What are you taking Tenormin for?

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  • Other
  • Angina Pectoris
  • Atrial Fibrillation
  • Atrial Flutter
  • Hypertension
  • Myocardial Infarction
  • Tachycardia, Supraventricular
  • Tachycardia, Ventricular
  • Ventricular Fibrillation

How long have you been taking it?

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  • Less than a week
  • A couple weeks
  • A month or so
  • A few months
  • A year or so
  • Two years or more

How well did Tenormin work for you?

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How likely would you be to recommend Tenormin to a friend?

Tenormin Cautionary Labels


Uses of Tenormin

Tenormin is a prescription medicine used alone or in combination with other medicines to treat high blood pressure. It also is used to prevent angina (chest pain) and improve survival after a heart attack.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.


Tenormin Drug Class

Tenormin is part of the drug class:

Side Effects of Tenormin

Tenormin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • dizziness
  • lightheadedness
  • tiredness
  • drowsiness
  • depression
  • nausea
  • diarrhea

Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them, call your doctor immediately:

  • shortness of breath
  • swelling of the hands, feet, ankles, or lower legs
  • unusual weight gain
  • fainting

Tenormin may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

Tenormin Interactions

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take: 

Your doctor may need to change the doses of your medications or monitor you carefully for side effects.

Tenormin Precautions

Before taking Tenormin,

  • tell your doctor and pharmacist if you are allergic to Tenormin or any other medications.
  • tell your doctor if you have or have ever had asthma or other lung disease; diabetes; severe allergies; an overactive thyroid gland (hyperthyroidism); pheochromocytoma; heart failure; a slow heart rate; circulation problems; or heart or kidney disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking Tenormin, call your doctor immediately.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking Tenormin.
  • you should know that if you have allergic reactions to different substances, your reactions may be worse while you are using Tenormin, and your allergic reactions may not respond to the usual doses of injectable epinephrine.

Tenormin can cause dizziness or drowsiness. Do not drive or operate heavy machinery until you know how Tenormin affects you.

Tenormin should not be taken/contraindicated if you:

  • have sinus bradycardia, heart block greater than first degree, cardiogenic shock, and overt cardiac failure. These conditions are diagnosed by your doctor.
  • have an allergy to Tenormin 

Tenormin Food Interactions

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Tenormin there are no specific foods that you must exclude from your diet when receiving. If your doctor prescribes a low-salt or low-sodium diet, follow these directions carefully.

Inform MD

Tell your doctor about all of your medical conditions including if you have: liver or kidney problems, lung disease, or allergies to medications.

Tell your doctor if you are pregnant or breastfeeding.

Tell your doctor about all the medicines you take.

Keep all appointments with your doctor. Your blood pressure should be checked regularly to determine your response to Tenormin. Your doctor may ask you to check your pulse (heart rate). Ask your pharmacist or doctor to teach you how to take your pulse. If your pulse is faster or slower than it should be, call your doctor.

Do not stop taking Tenormin without talking to your doctor. Suddenly stopping Tenormin may cause chest pain, heart attack, or irregular heartbeat. Your doctor will probably decrease your dose gradually.

Tenormin and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant. 

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Tenormin falls into category D. It has been shown that use of Tenormin in pregnant women caused some babies to be born with problems. Tenormin can cause fetal harm when administered to a pregnant woman. Tenormin crosses the placental barrier and appears in cord blood. Tenormin use in pregnant women resulted in children born small in size with low sugar and slow heart rate.  Caution should be exercised Tenormin is used during pregnancy or to a woman who is breast feeding. However, in some serious situations, the benefit of using this medication may be greater than the risk of harm to the baby.

Tenormin and Lactation

Tell your doctor if you are breastfeeding or plan to breastfeed. 

Tenormin is excreted in human breast milk. Slow heart rate has been reported in breast-fed infants. Premature infants, or infants with impaired kidney function, may be more likely to develop adverse effects.


Tenormin Usage

Tenormin comes as a tablet. It is taken once or twice daily.

This medication can be taken with or without food.

Try to take Tenormin at the same time(s) everyday.

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose. 

This medication is also available in an injectable form to be given directly into a vein (IV) by a healthcare professional.

Tenormin Dosage

Take Tenormin exactly as prescribed by your doctor. Follow the directions on your prescription label carefully. Your doctor will determine the best dose for you. The dosage of Tenormin must be individualized.

Do not take more than 200 mg a day.

Tenormin Overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Symptoms of overdose may include:

  • lack of energy
  • difficulty breathing
  • wheezing
  • slow heartbeat
  • fainting
  • swelling of the hands, feet, ankles, or lower legs
  • unusual weight gain
  • shakiness
  • dizziness
  • rapid heartbeat
  • sweating or confusion
  • blurred vision
  • headache
  • numbness or tingling of the mouth
  • weakness
  • excessive tiredness
  • pale color
  • sudden hunger

Other Requirements

  • Keep this medication in the container it came in, tightly closed, and out of reach of children.
  • Store it at room temperature and away from excess heat and moisture (not in the bathroom). 

Tenormin FDA Warning

Cessation of Therapy with Tenormin 

Patients with coronary artery disease, who are being treated with Tenormin, should be advised against abrupt discontinuation of therapy. Severe exacerbation of angina and the occurrence of myocardial infarction and ventricular arrhythmias have been reported in angina patients following the abrupt discontinuation of therapy with beta-blockers. The last two complications may occur with or without preceding exacerbation of the angina pectoris. As with other beta-blockers, when discontinuation of Tenormin tablet, USP, is planned, the patients should be carefully observed and advised to limit physical activity to a minimum. If the angina worsens or acute coronary insufficiency develops, it is recommended that Tenormin  tablet, USP be promptly reinstituted, at least temporarily. Because coronary artery disease is common and may be unrecognized, it may be prudent not to discontinue Tenormin tablet, USP, therapy abruptly even in patients treated only for hypertension.