Tenormin is a brand-name prescription drug that’s FDA-approved for the following uses:

Tenormin is approved for these uses in adults. This drug hasn’t been studied for use in children.

Drug details

Tenormin contains the active drug atenolol. It belongs to a class of drugs called beta-blockers. (A drug class describes a group of medications that work in the same way.) Beta-blockers help your blood vessels to relax, which means your heart doesn’t have to work so hard. This can help lower your blood pressure, and it may prevent heart attack and heart damage.

Tenormin comes as tablets that are taken by mouth. It’s available in three strengths: 25 mg, 50 mg, and 100 mg.

Effectiveness

For information on the effectiveness of Tenormin, see the “Tenormin uses” section below.

Tenormin contains the active drug atenolol. This active drug is available as both the brand-name drug Tenormin and a generic medication. (A generic medication is an exact copy of the active drug in a brand-name medication.)

Generics are considered to be as safe and effective as the original drug. And generics tend to cost less than brand-name drugs.

Tenormin can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Tenormin. These lists don’t include all possible side effects.

For more information on the possible side effects of Tenormin, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to report to the FDA a side effect you’ve had with Tenormin, you can do so through MedWatch.

Mild side effects

Mild side effects of Tenormin can include:*

Most of these side effects may go away within a few days or a couple of weeks. But if they become more severe or don’t go away, talk with your doctor or pharmacist.

* This is a partial list of mild side effects from Tenormin. To learn about other mild side effects, talk with your doctor or pharmacist, or visit Tenormin’s prescribing information.
† This mild side effect is explained further in the “Side effect details” section below.

Serious side effects

Serious side effects from Tenormin aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Serious side effects and their symptoms can include:

* With cardiac arrest, you have a sudden stop in your heart function that’s caused by electrical problem in your heart.
** With cardiogenic shock, your heart isn’t able to pump enough blood to the rest of your body.
† With CAD, you have narrowed arteries in your heart.
‡ This serious side effect is a boxed warning for Tenormin. A boxed warning is the strongest warning required by the Food and Drug Administration (FDA). Boxed warnings alert doctors and patients about drug effects that may be dangerous. This warning is discussed in more detail above in the section “FDA warning: Suddenly stopping Tenormin in people with CAD.”

Side effect details

You may wonder how often certain side effects occur with this drug, or whether certain side effects pertain to it. Here’s some detail on certain side effects this drug may or may not cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Tenormin. But it’s not known how many people taking Tenormin in clinical studies had an allergic reaction to the drug.

Symptoms of a mild allergic reaction can include:

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing

Call your doctor right away if you have a severe allergic reaction to Tenormin. But call 911 or your local emergency number if your symptoms feel life threatening or you think you’re having a medical emergency.

Skin rash

It’s important to note that beta-blockers, such as Tenormin, may cause a skin rash that’s not severe and not related to an allergic reaction. (Beta-blockers are a specific group of drugs that work in a similar way.)

The non-severe skin rash that’s caused by beta-blockers looks different than the rash caused by allergic reaction. For example, the non-severe rash related to beta-blockers may cause dry or itchy skin. Or it may also cause red or purple bumps on your skin.

The skin rash caused by an allergic reaction, on the other hand, typically causes hives (red, itchy bumps). Allergic reaction may also cause swelling of your mouth, lips, tongue, throat, eyelids, hands, or feet.

The skin rash caused by beta-blockers typically goes away if treatment with the beta-blocker is stopped.

If you have any skin changes while you’re taking Tenormin, let your doctor know right away. Your doctor can recommend ways to help you manage your skin symptoms. And they can check to make sure you’re not having an allergic reaction to the drug.

Hair loss

Hair loss has been reported in some people taking Tenormin. But it’s not known for sure how many people have been affected by hair loss with Tenormin. In most cases, this hair loss is reversible once Tenormin is stopped.

If you’re concerned about hair loss during Tenormin treatment, talk with your doctor.

Slowed heart rate

Tenormin can cause a slow heart rate in some people. For example, in clinical studies of people with high blood pressure, slow heart rate occurred in:

  • 3% of people taking Tenormin
  • 0% of people taking a placebo (treatment with no active drug)

Symptoms of slow heart rate may include feeling faint or fainting, dizziness, or tiredness. Slow heart rate may also lead to trouble breathing.

If you’re concerned about having a slow heart rate while taking Tenormin, talk with your doctor. But if you feel faint or have shortness of breath, call your doctor right away.

Dizziness

It’s possible to feel dizzy while you’re taking Tenormin. In clinical studies of people with high blood pressure, dizziness occurred in:

  • 13% of people taking Tenormin
  • 6% of the people taking a placebo (treatment with no active drug)

If you have dizziness while you’re taking Tenormin, talk with your doctor. They may suggest ways to help reduce this side effect. They may also recommend treatment options other than Tenormin for your condition.

Low blood pressure

Tenormin is used to lower blood pressure in people with high blood pressure. And the drug is also used for other heart-related conditions. But in some people, Tenormin may cause low blood pressure.

In a clinical study of people who’d had a heart attack, low blood pressure occurred in:

  • 25% of people taking Tenormin with other typical treatments for heart attack
  • 15% of people taking typical treatments for heart attack

Symptoms of low blood pressure may include feeling faint or fainting, dizziness, and tiredness.

If you’re concerned about having low blood pressure while taking Tenormin, talk with your doctor. But if you feel dizzy or faint, call your doctor right away.

Anxiety (not a side effect)

Anxiety isn’t a reported side effect of Tenormin.

However, anxiety may be a symptom of the condition you’re using Tenormin to treat. For example, people with severe chest pain may have anxiety related to having the chest pain. (Tenormin is used to treat a certain type of chest pain called stable angina.)

Also, keep in mind that Tenormin can cause changes in your heart rate. For some people, anxiety can also cause changes in heart rate. But having changes in your heart rate with Tenormin doesn’t always mean you have anxiety.

If you feel anxious during Tenormin treatment, talk with your doctor. They can suggest ways to help reduce your anxiety.

The Tenormin dosage your doctor prescribes will depend on several factors. These include:

  • the type and severity of the condition you’re using Tenormin to treat
  • your age
  • other medical conditions you may have
  • other medications you may take
  • how your body responds to Tenormin, including any side effects that you may have

Typically, your doctor will start you on a low dosage. Then they’ll adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Drug forms and strengths (25 mg, 50 mg, 100 mg)

Tenormin contains the active drug atenolol. It comes as tablets that are taken by mouth. And it’s available in the following strengths: 25 mg, 50 mg, and 100 mg.

Dosage for high blood pressure

The typical Tenormin dosage for hypertension (high blood pressure) is 50 mg once daily.

Depending on how your body responds to Tenormin, your doctor may gradually increase your dosage of the drug. But Tenormin dosages for high blood pressure typically aren’t greater than 100 mg each day.

Dosage for stable angina due to atherosclerosis in the heart

Tenormin is used to treat stable angina (a type of chest pain) that’s due to atherosclerosis (narrowed arteries) in your heart. The typical starting dose of Tenormin for this use is 50 mg once daily.

Depending on how your body responses to Tenormin, your doctor may increase your dosage of the drug. But Tenormin dosages for this type of chest pain typically aren’t greater than 200 mg each day.

Dosage for heart attack

Tenormin is used in people who’ve had a known or suspected heart attack. For this use, the drug is given to reduce the risk of death that’s related to heart or blood vessel problems.

The typical dosage for this use varies, but it could be 100 mg once daily or 50 mg twice daily.

What if I miss a dose?

If you miss a dose of Tenormin, call your doctor’s office. Your doctor or their medical staff can recommend when you should take your next dose of the drug.

To help make sure that you don’t miss a dose, try setting a reminder on your phone. A kitchen timer may be useful, too.

Will I need to use this drug long term?

Tenormin is meant to be used as a long-term treatment for its approved uses. If you and your doctor determine that Tenormin is safe and effective for you, you’ll likely take it long term.

The Food and Drug Administration (FDA) approves prescription drugs such as Tenormin to treat certain conditions. Tenormin may also be used off-label for other conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Tenormin for high blood pressure

Tenormin is used to treat hypertension (high blood pressure) in adults. For this use, Tenormin may be used alone or in combination with other blood pressure drugs.

Symptoms of high blood pressure can include:

However, many people with high blood pressure don’t have any symptoms of the condition. In some cases, you might have high blood pressure for many years before you notice any symptoms.

If hypertension isn’t treated, it may lead to serious and sometimes fatal complications. These complications include damage to your arteries and heart. In addition, high blood pressure could lead to decreased blood supply to your brain, which may result in brain damage.

Effectiveness for high blood pressure

In clinical studies, Tenormin was effective in treating high blood pressure. When Tenormin was given once daily, it lowered people’s blood pressure over a 24-hour period.

Tenormin for stable angina due to atherosclerosis in the heart

Tenormin is used to treat stable angina (a type of chest pain) that’s due to atherosclerosis (narrowed arteries) in your heart. This condition is also sometimes called angina pectoris due to coronary atherosclerosis.

With atherosclerosis, your arteries become hardened and narrowed. Atherosclerosis that forms in the arteries in your heart leads to a condition called coronary artery disease (CAD).

CAD can cause a type of chest pain called angina. With stable angina you can have chest pain when your heart has to work hard, such as when you’re exercising. But with unstable angina, you can also have chest pain occur when you’re resting.

Tenormin may help reduce chest pain in people with stable angina that’s related to CAD.

Effectiveness for stable angina due to atherosclerosis in the heart

In one study that was done in 1979, people with stable angina who took atenolol had their chest pain reduced. (Atenolol is the active drug in Tenormin.) In addition, they didn’t need to use nitroglycerin treatment as much as they did before taking atenolol. (Nitroglycerin is a medication that’s used to relieve sudden and severe chest pain.)

Because Tenormin has been used for a long time, many of the studies on its use are older. These studies were done differently than studies that are done today. There isn’t always as much information available from older studies as there is from newer studies.

Tenormin for heart attack

Tenormin is approved for use in people who’ve had a known or suspected heart attack. For this use, the drug is given to reduce the risk of death that’s related to heart or blood vessel problems.

During a heart attack, blood flow stops in certain areas of your heart. This can damage your heart, making it weak and less able to function properly.

Tenormin helps to reduce the amount of work your heart has to do as it pumps blood through your body. In this way, the drug may lower your risk of death that’s related to a heart or blood vessel problem.

Effectiveness for heart attack

Clinical studies looked at people who were thought to have had a heart attack. In this study, within the first 7 days after the heart attack, death related to a heart problem occurred in:

  • 3.89% of people who took Tenormin
  • 4.57% of people who didn’t take Tenormin

In other words, the risk of dying due to a heart problem in the first 7 days after a heart attack was reduced by 15% in people who took Tenormin.

Off-label use for Tenormin

In addition to the uses listed above, Tenormin may be used off-label for other purposes. Off-label drug use is when a drug that’s approved for one or more uses is prescribed for a different one that’s not approved. Below is an example of off-label use for Tenormin.

Tenormin for migraine

Tenormin isn’t FDA-approved to treat migraine. However, the drug is sometimes used off-label to treat this condition. With migraine, you can have severe and sometimes debilitating headaches.

In one clinical study, after 3 months, people taking atenolol had fewer days each month with migraine headaches than they had prior to treatment. (Atenolol is the active drug in Tenormin.)

If you’d like to know more about using Tenormin for migraine, talk with your doctor. They can recommend appropriate treatment options for your condition.

Tenormin and children

Tenormin isn’t approved for use in children. This drug has only been studied in adults. So it’s not known whether Tenormin is safe or effective when used in children.

As with all medications, the cost of Tenormin can vary. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

Before approving coverage for Tenormin, your insurance company may require you to get prior authorization. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the prior authorization request and decide if the drug will be covered.

If you’re not sure if you’ll need to get prior authorization for Tenormin, contact your insurance company.

Financial assistance

NeedyMeds.org is a website that lists cost-assistance programs for certain drugs. For more information and to find out if there are ways to lower the cost of Tenormin, visit the NeedyMeds website.

Generic version

Tenormin is available in a generic form called atenolol. A generic drug is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the original drug. And generics tend to cost less than brand-name drugs.

If your doctor has prescribed Tenormin and you’re interested in using atenolol instead, talk with your doctor. They may have a preference for one version or the other. You’ll also need to check your insurance plan, as it may only cover one or the other.

Other drugs are available that can treat your condition. Some may be a better fit for you than others. If you’re interested in finding an alternative to Tenormin, talk with your doctor. They can tell you about other medications that may work well for you.

Note: Some of the drugs listed here are used off-label to treat these specific conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Alternatives for high blood pressure

Examples of other drugs that may be used to treat hypertension (high blood pressure) include:

Alternatives for stable angina due to atherosclerosis in the heart

Examples of other drugs that may be used to treat stable angina (a type of chest pain) that’s due to atherosclerosis (hardened arteries) in your heart include:

Alternatives for heart attack

Examples of other drugs that may be used to lower the risk of death due to heart or blood vessel problem in people who’ve had a heart attack include:

Using more than the recommended dosage of Tenormin can lead to serious side effects. Do not use more Tenormin than your doctor recommends.

Overdose symptoms

Symptoms of Tenormin overdose can include:

What to do in case of overdose

If you think you’ve taken too much of this drug, call your doctor. You can also call the American Association of Poison Control Centers at 800-222-1222 or use their online tool. But if your symptoms are severe, call 911 or your local emergency number, or go to the nearest emergency room right away.

This drug comes with several precautions.

FDA warning: Suddenly stopping Tenormin in people with CAD

This drug has a boxed warning. This is the most serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous.

If you have coronary artery disease (CAD), it’s important that you don’t abruptly stop taking Tenormin. (With CAD, you have narrowed arteries in your heart.) Suddenly stopping Tenormin may cause worsened chest pain or increased blood pressure. It may even lead to heart attack.

If you have CAD and need to stop taking Tenormin, talk with your doctor. They’ll recommend a treatment plan to help you safely stop taking this drug. Typically, your doctor will gradually reduce your Tenormin dosage over a period of time, until it’s safe for you to completely stop treatment.

Other warnings

Before taking Tenormin, talk with your doctor about your health history. Tenormin may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Hyperthyroidism or history of thyroid storm. Using beta-blockers (a certain group of drugs), such as Tenormin, may mask certain symptoms of hyperthyroidism. (With hyperthyroidism, your thyroid hormone levels are elevated.) These masked symptoms may include increased heart rate. And suddenly stopping Tenormin might result in thyroid storm (a dangerous condition that’s related to hyperthyroidism). If you have hyperthyroidism, talk with your doctor before taking Tenormin.
  • Diabetes. If you have diabetes, you may be using certain drugs that increase your risk of low blood sugar level. Taking beta-blockers (a certain group of drugs), including Tenormin, may mask symptoms of low blood sugar level. Specifically, Tenormin may mask the symptom of having an increased heart rate when your blood sugar is low. If you have diabetes, talk with your doctor about how to monitor for low blood sugar while you’re taking Tenormin.
  • Asthma, COPD, or other airway diseases. Using beta-blockers (a certain group of drugs), including Tenormin, may worsen certain conditions that affect your airway. These conditions include asthma and chronic obstructive pulmonary disease (COPD). If you have an airway disease, including asthma or COPD, be sure to tell your doctor before taking Tenormin.
  • Untreated pheochromocytoma. A pheochromocytoma is a tumor that causes your body to secrete too many catecholamines (certain types of hormones). If Tenormin is used in someone with an untreated pheochromocytoma, it could cause serious increases in blood pressure. The drug could also cause their lungs to fill with fluid (pulmonary edema). Before taking Tenormin, tell your doctor if you have a pheochromocytoma.
  • Allergic reaction. If you’ve had an allergic reaction to Tenormin or any of its ingredients, you shouldn’t take Tenormin. Ask your doctor what other medications are better options for you. And if you’re unsure of your medication allergies, talk with your doctor.
  • Pregnancy. It’s recommended that you don’t use Tenormin during pregnancy. If you’re pregnant or planning a pregnancy, talk with your doctor about treatment options that are safe for your condition. For more information, please see the “Tenormin and pregnancy” section above.
  • Breastfeeding. Drugs other than Tenormin may be preferred in people who are breastfeeding. For more information, please see the “Tenormin and breastfeeding” section above.

Note: For more information about the potential negative effects of Tenormin, see the “Tenormin side effects” section above.

Here are answers to some frequently asked questions about Tenormin.

Can Tenormin cause anxiety or depression?

Yes, in some cases, Tenormin may cause depression. For example, in clinical studies, depression occurred in:

  • 12% of people taking Tenormin
  • 9% of people taking a placebo (treatment with no active drug)

In clinical studies, there weren’t any reports of anxiety in people taking Tenormin. But keep in mind that anxiety and depression often occur together.

In addition, anxiety may be a symptom of the condition you’re using Tenormin to treat. For example, people with severe chest pain may have anxiety related to having the chest pain. (Tenormin is used to treat a certain type of chest pain called stable angina.)

Also, keep in mind that Tenormin can cause changes in your heart rate. For some people, anxiety can also cause changes in heart rate. But having changes in your heart rate with Tenormin doesn’t always mean you have anxiety.

If you’re have anxiety or depression while you’re taking Tenormin, talk with your doctor. They can recommend ways to help reduce these symptoms.

Am I able to use Tenormin if I have kidney disease?

Possibly. If you have kidney disease, you might be able to use Tenormin, but it depends on:

  • how well your kidneys are functioning
  • the condition you’re using Tenormin to treat

Before starting Tenormin, tell your doctor about any kidney problems you have. Your doctor will determine if Tenormin is safe for you to use. In some cases, they may prescribe a starting dose of the drug for you that’s lower than the usual starting dose.

Will Tenormin cure my condition?

No, unfortunately it won’t. Tenormin is approved for use in people with high blood pressure, a certain type of angina (chest pain), or known or suspected heart attack. But the drug doesn’t cure these conditions. Instead, it helps to manage symptoms related to these conditions.

If you have questions about what you can expect from Tenormin treatment, talk with your doctor.

What should I know about Tenormin if I have coronary artery disease?

If you have coronary artery disease (CAD), it’s important that you don’t abruptly stop taking Tenormin. (With CAD, you have narrowed arteries in your heart.)

In fact, Tenormin has a boxed warning stating that people with CAD shouldn’t suddenly stop taking the drug. A boxed warning is the strongest warning required by the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.

If you have CAD, abruptly stopping Tenormin may cause worsened chest pain or increased blood pressure. It may even lead to heart attack.

If you have CAD and need to stop taking Tenormin, talk with your doctor. They’ll recommend a treatment plan to help you safely stop taking this drug. Typically, your doctor will gradually reduce your Tenormin dosage over a period of time, until it’s safe for you to completely stop treatment.

Can I use Tenormin if I have COPD or asthma?

In general, you shouldn’t take Tenormin if you have asthma or chronic obstructive pulmonary disease (COPD). However, in some cases, your doctor may prescribe this drug for you if you have one of these conditions. In those cases, your doctor will likely recommend a starting dosage of Tenormin that’s lower than usual. And they’ll carefully monitor you during treatment.

Tenormin works by blocking receptors (attachment sites on cells) in your heart called beta receptors. However, Tenormin can also block beta receptors in other parts of your body, such as your airways. And blocking these receptors in your airways could narrow the airways, making your asthma or COPD symptoms worse.

If you have asthma or COPD, be sure to talk with your doctor before starting Tenormin. They’ll recommend whether it’s safe for you to use this drug.

You may wonder how Tenormin compares with other medications that are prescribed for similar uses. Here we look at how Tenormin and Lopressor are alike and different.

Ingredients

Tenormin contains the drug atenolol, while Lopressor contains the drug metoprolol tartrate. These medications both belong to a group of drugs called beta-blockers.

Uses

Both Tenormin and Lopressor are approved to:

  • treat high blood pressure; for this use, Tenormin and Lopressor can each be used alone or with other blood pressure drugs
  • treat stable angina (a type of chest pain); for this use, Tenormin is specifically approved for use in people with atherosclerosis (hardened arteries) in their heart
  • reduce the risk of death that’s related to heart or blood vessel problems in people with a known or suspected heart attack

Drug forms and administration

Tenormin and Lopressor both come as tablets that are taken by mouth. Typically, Tenormin is taken once each day and Lopressor is taken once or twice each day.

Side effects and risks

Tenormin and Lopressor are both beta-blockers. Therefore, these medications can cause very similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with Tenormin, with Lopressor, or with both drugs (when taken individually).

  • Can occur with Tenormin:
    • no unique mild side effects
  • Can occur with Lopressor:
    • short-term memory loss
    • sleep issues, such as insomnia (trouble sleeping) and nightmares
  • Can occur with both Tenormin and Lopressor:
    • cold hands and feet
    • tiredness
    • diarrhea
    • dizziness
    • leg pain

Serious side effects

These lists contain examples of serious side effects that can occur with Tenormin, with Lopressor, or with both drugs (when taken individually).

* Tenormin and Lopressor both have a boxed warning regarding this risk. A boxed warning is the strongest warning required by the Food and Drug Administration (FDA). Boxed warnings alert doctors and patients about drug effects that may be dangerous.

Effectiveness

In certain situations, both Tenormin and Lopressor are approved for use in people with high blood pressure, stable angina, and known or suspected heart attack.

These drugs haven’t been directly compared in clinical studies. But separate studies have found both Tenormin and Lopressor to be effective for their approved uses.

Costs

Tenormin and Lopressor generally cost about the same. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Tenormin and Lopressor are both brand-name drugs. Tenormin is available as the generic medication atenolol. And Lopressor is available as the generic medication metoprolol tartrate. (A generic drug is an exact copy of the active drug in a brand-name medication.)

Brand-name medications usually cost more than generics.

Like Lopressor (described above), Zestril has uses similar to those of Tenormin. Here’s a comparison of how Tenormin and Zestril are alike and different.

Ingredients

Tenormin contains the active drug atenolol, while Zestril contains the active drug lisinopril.

These drugs belong to different classes of blood pressure medications. (A drug class describes a group of drugs that work in the same way.) Specifically, Tenormin is a beta-blocker and Zestril is an angiotensin converting enzyme (ACE) inhibitor.

Uses

Here is a list of conditions that the Food and Drug Administration (FDA) has approved Tenormin and Zestril to treat.

  • Both Tenormin and Zestril are FDA-approved to:
    • treat high blood pressure;* for this use, Tenormin and Zestril can each be used alone or with other blood pressure drugs
    • reduce the risk of death that’s related to heart or blood vessel problems in people who’ve had a heart attack; for this use, Tenormin may be used in people with a known or suspected heart attack
  • Tenormin is also FDA-approved to treat:
    • stable angina (a type of chest pain) in people with narrowed arteries in their heart
  • Zestril is also FDA-approved to treat:

* For treating high blood pressure, Tenormin is approved for use in adults. But Zestril may be used in adults and children ages 6 years and older.

Drug forms and administration

Tenormin and Zestril both come as tablets that are taken by mouth. Typically, Tenormin is taken once each day and Zestril is taken once or twice each day.

Side effects and risks

Tenormin and Zestril have some similar side effects and others that vary. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with Tenormin, with Zestril, or with both drugs (when taken individually).

Serious side effects

These lists contain examples of serious side effects that can occur with Tenormin, with Zestril, or with both drugs (when taken individually).

* Tenormin has a boxed warning regarding this risk. A boxed warning is the strongest warning required by the Food and Drug Administration (FDA). Boxed warnings alert doctors and patients about drug effects that may be dangerous.
† Zestril has a boxed warning regarding this risk.

Effectiveness

In certain situations, both Tenormin and Zestril are approved for use in people with high blood pressure and heart attack.

These drugs haven’t been directly compared in clinical studies. But separate studies have found both Tenormin and Zestril to be effective in:

  • treating high blood pressure
  • reducing the risk of death that’s related to heart or blood vessel problems in people who’ve had a heart attack

Costs

Tenormin and Zestril generally cost about the same. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Tenormin and Zestril are both brand-name drugs. Tenormin is available as the generic medication atenolol. And Zestril is available as the generic medication lisinopril. (A generic drug is an exact copy of the active drug in a brand-name medication.)

Brand-name medications usually cost more than generics.

Tenormin is approved to treat high blood pressure and a certain type of chest pain. It’s also used to reduce the risk of death related to heart or blood vessel problems in people who’ve had a known or suspected heart attack.

When it’s used to treat high blood pressure, Tenormin can be used alone or with other blood pressure drugs. Examples of other blood pressure drugs that may be used with Tenormin include:

For its other approved uses, Tenormin may be used with certain other drugs, depending on your doctor’s recommendation.

There aren’t any known interactions between Tenormin and alcohol.

However, certain side effects of Tenormin can be worsened if you drink alcohol while taking this drug. These side effects include diarrhea, dizziness, and tiredness.

If you drink alcohol, talk with your doctor about how much is safe for you to drink during Tenormin treatment.

Tenormin can interact with several other medications.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase side effects or make them more severe.

Tenormin and other medications

Below are lists of medications that can interact with Tenormin. These lists doesn’t contain all the drugs that may interact with Tenormin.

Before taking Tenormin, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Tenormin and drugs that lower your level of catecholamines

Taking Tenormin with drugs that lower your level of catecholamines may cause your blood pressure to be too low. (Catecholamines are certain types of hormones.) In addition, taking these medications together could also lower your heart rate.

Symptoms of low blood pressure or low heart rate vary. But they may include dizziness, lightheadedness, and fainting.

Examples of drugs that lower catecholamine levels include:

If you must take drugs that lower catecholamine levels while you’re using Tenormin, your doctor will closely monitor your heart function and blood pressure during treatment.

Tenormin and calcium channel blockers

Taking Tenormin with blood pressure drugs called calcium channel blockers may cause your blood pressure to be too low. In addition, taking these medications together could lower your heart rate.

Symptoms of low blood pressure or low heart rate vary. But they may include dizziness, lightheadedness, and fainting.

Examples of calcium channel blockers include:

If you must take calcium channel blockers while you’re using Tenormin, your doctor will closely monitor your heart function and blood pressure during treatment.

Tenormin and disopyramide

Taking Tenormin with disopyramide (Norpace, Rythmodan) can cause a dangerously slow heart rate. (Disopyramide is used to treat irregular heart rhythm.)

Symptoms of slow heart rate may include dizziness, lightheadedness, and fainting.

If you must take disopyramide while you’re using Tenormin, your doctor will closely monitor your heart function during treatment.

Tenormin and amiodarone

Taking Tenormin with amiodarone (Pacerone, Nexterone) can cause a slow heart rate. (Amiodarone is used to treat irregular heart rhythm.)

Symptoms of slow heart rate may include dizziness, lightheadedness, and fainting.

If you must take amiodarone while you’re using Tenormin, your doctor will closely monitor your heart function during treatment.

Tenormin and clonidine

If you’re taking both Tenormin and clonidine (Catapres), it’s important to talk with your doctor before stopping either medication. (Clonidine is used to treat high blood pressure.)

Abruptly stopping either drug could cause a sudden increase in your blood pressure. (This condition is also called rebound hypertension.)

Tenormin and drugs that lower prostaglandin levels

Taking Tenormin with drugs that lower prostaglandin levels may lower Tenormin’s effectiveness in treating high blood pressure. (Prostaglandins are substances in your body that have hormone-like effects.) This means Tenormin may not work as well as usual to lower your blood pressure.

An example of a drug that lowers prostaglandin levels is the pain reliever indomethacin (Indocin).

If you must take a drug that lowers prostaglandin levels while you’re using Tenormin, your doctor will closely monitor your blood pressure during treatment.

Tenormin and digitalis glycosides

Taking Tenormin with certain heart drugs called digitalis glycosides can cause a dangerously slow heart rate. An example of a digitalis glycoside drug is digoxin (Lanoxin).

Symptoms of slow heart rate may include dizziness, lightheadedness, and fainting.

If you must take a digitalis glycoside drug while you’re taking Tenormin, your doctor will closely monitor your heart function during treatment.

Tenormin and herbs and supplements

There aren’t any herbs or supplements that have been specifically reported to interact with Tenormin. However, you should still check with your doctor or pharmacist before using any of these products while taking Tenormin.

Tenormin and foods

There aren’t any foods that have been specifically reported to interact with Tenormin. If you have any questions about eating certain foods with Tenormin, talk with your doctor.

Tenormin comes as tablets that are taken by mouth. You should take Tenormin according to your doctor’s or another healthcare professional’s instructions.

When to take

Tenormin is typically taken once each day. It’s usually best to take the drug around the same time every day. But it doesn’t matter exactly what time of day you take Tenormin, as long as you’re consistent.

To help make sure that you don’t miss a dose, try setting a reminder on your phone. A kitchen timer may be useful, too.

Taking Tenormin with food

Tenormin can be taken with or without food.

Can Tenormin be split or chewed?

If your doctor recommends it, Tenormin tablets can be split or cut in half. However, it’s not recommended that you chew Tenormin tablets. Instead, they should be swallowed.

Tenormin is approved for the following uses:

  • treating hypertension (high blood pressure)
  • treating stable angina (a type of chest pain) that’s due to atherosclerosis (narrowed arteries) in your heart
  • reducing the risk of death related to heart or blood vessel problems in people who’ve had a known or suspected heart attack

Tenormin contains the active drug atenolol. It belongs to a class of drugs called beta-blockers. (A class of drugs describes a group of medications that work in the same way.)

Beta-blockers work by helping your blood vessels to relax. So with a beta-blocker, your heart doesn’t have to work as hard to pump blood through your body. In addition, your heart has to use less oxygen to do its work.

By working in these ways, Tenormin helps to lower blood pressure. The drug may also help to reduce chest pain and prevent heart attacks and heart damage.

How long does it take to work?

Tenormin starts working right away in your body. This drug continues to work over a period of about 24 hours. So, it’s important to take Tenormin consistently every day to allow it to work well.

Tenormin shouldn’t be used during pregnancy. This is because the drug may cause serious harm to a developing fetus. Tenormin may also cause low birth weight in infants exposed to it during pregnancy.

If you’re pregnant or planning to become pregnant, talk with your doctor before taking Tenormin. Your doctor can recommend appropriate treatment options for your condition.

Tenormin shouldn’t be taken during pregnancy. If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control needs while you’re using Tenormin.

For more information about taking Tenormin during pregnancy, see the “Tenormin and pregnancy” section above.

Tenormin is known to pass into human breast milk. And there’s a possibility that the drug could cause harm in a child who’s breastfed. Because of this, other drugs may be preferred over Tenormin if you’re breastfeeding.

If you’re breastfeeding or planning to breastfeed, talk with your doctor. They can recommend safe and healthy ways to feed your child.

Tenormin doesn’t cause dependence. (With dependence, your body needs a certain drug in order for you to feel normal.) However, stopping Tenormin treatment may cause very serious and possibly dangerous conditions. Below, we describe these possible conditions.

If you need to stop taking Tenormin, talk with your doctor. They’ll recommend a treatment plan to help you safely stop taking this drug.

Suddenly stopping Tenormin in people with CAD

If you have coronary artery disease (CAD), it’s important that you don’t abruptly stop taking Tenormin. (With CAD, you have narrowed arteries in your heart.)

If you have CAD, suddenly stopping Tenormin may cause worsened chest pain or increased blood pressure. It may even lead to a heart attack.

In fact, Tenormin has a boxed warning for this possible effect. This is the most serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous.

If you have CAD and need to stop taking Tenormin, talk with your doctor. They’ll recommend a treatment plan to help you safely stop taking this drug. Typically, your doctor will gradually reduce your Tenormin dosage over a period of time, until it’s safe for you to completely stop treatment.

Stopping Tenormin in people with chest pain

If you’re taking Tenormin for a certain type of chest pain, you shouldn’t suddenly stop taking the drug. Suddenly stopping Tenormin may cause worsened chest pain. Instead, if you need to stop treatment, your doctor will have you gradually stop taking Tenormin.

In addition, your doctor should monitor you closely while you’re stopping treatment. They may also recommend that you limit the amount of physical activity you do while you’re stopping treatment.

Stopping Tenormin in people with hyperthyroidism

If you have hyperthyroidism, using Tenormin may mask certain symptoms of your thyroid condition. (With hyperthyroidism, your thyroid hormone levels are elevated.) And suddenly stopping Tenormin might result in thyroid storm (a dangerous condition that’s related to hyperthyroidism).

If you need to stop taking Tenormin, talk with your doctor. They’ll recommend a treatment plan to help you safely stop taking this drug. Typically, your doctor will gradually reduce your Tenormin dosage over a period of time, until it’s safe for you to completely stop treatment.

When you get Tenormin from the pharmacy, the pharmacist will add an expiration date to the label on the bottle. This date is typically 1 year from the date they dispensed the medication.

The expiration date helps guarantee that the medication is effective during this time. The current stance of the Food and Drug Administration (FDA) is to avoid using expired medications. If you have unused medication that has gone past the expiration date, talk to your pharmacist about whether you might still be able to use it.

Storage

How long a medication remains good can depend on many factors, including how and where you store the medication.

Tenormin tablets should be stored at a room temperature of 68°F to 77°F (20°C to 25°C). They should be kept in a tightly sealed container away from light. Avoid storing this medication in areas where it could get damp or wet, such as in bathrooms.

Disposal

If you no longer need to take Tenormin and have leftover medication, it’s important to dispose of it safely. This helps prevent others, including children and pets, from taking the drug by accident. It also helps keep the drug from harming the environment.

This article provides several useful tips on medication disposal. You can also ask your pharmacist for information on how to dispose of your medication.

The following information is provided for clinicians and other healthcare professionals.

Indications

Tenormin is approved for the following uses in adults:

  • treatment of hypertension
  • long-term treatment of angina pectoris caused by coronary atherosclerosis
  • prevention of cardiovascular-related death in people with known or suspected heart attack

Administration

Tenormin tablets are taken by mouth, typically once daily.

Mechanism of action

Tenormin contains the beta-blocker atenolol. It is a beta-1-selective adrenoreceptor blocking agent, which targets beta receptors in the heart to relax blood vessels and decrease oxygen demand by the heart.

Pharmacokinetics and metabolism

Peak serum concentration of Tenormin occurs 2 hours to 4 hours after administration. The elimination half-life of Tenormin is nearly 6 to 7 hours.

Contraindications

Tenormin is contraindicated in people with the following conditions:

  • sinus bradycardia
  • greater than first-degree heart block
  • cardiogenic shock
  • heart failure
  • hypersensitivity to atenolol or any other ingredients in Tenormin

Misuse, withdrawal, and dependence

Tenormin has a boxed warning regarding the risk of abruptly stopping therapy in people with coronary artery disease (CAD). For people with CAD, Tenormin should not be suddenly discontinued. Doing so may result in severe worsening of angina, myocardial infarction, and ventricular arrhythmias.

In addition, Tenormin has warnings regarding use in people with angina pectoris or hyperthyroidism. In people with these conditions, abrupt discontinuation of therapy should also be avoided.

Storage

Tenormin should be stored at a room temperature of 68°F to 77°F (20°C to 25°C). It should be stored in the original container to protect it from light.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

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