Atenolol

Pronunciation: a-TEN-oh-lol.

Generic name
atenolol
Drug class
Beta-1 selective (cardioselective) beta-blocker
Form
Film-coated tablet (25 mg, 50 mg, 100 mg) or oral solution
Route
Oral (tablet or oral solution); intravenous under hospital supervision for some indications
Legal status
Prescription-only

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: Atenolol Sandoz / APX-Atenolol / Tenelol (6) · Full directory

What atenolol is and how it works

Atenolol is a prescription-only beta-blocker that works preferentially on beta-1 receptors in the heart, slowing the heart rate and reducing the heart's workload. It is used to treat high blood pressure and angina, and in some countries also cardiac arrhythmias and after a heart attack. (1) (3)

Take atenolol exactly as your prescriber directs, at the same time each day. Do not change your dose or stop taking it without talking to your prescriber first -- for some people, especially those with heart disease, stopping suddenly can be dangerous and any dose change should be gradually planned and supervised by a clinician.

Mechanism of action: how atenolol works

Atenolol is a beta-1 selective (cardioselective) beta-adrenergic receptor blocking agent without membrane-stabilising or intrinsic sympathomimetic activity. Selectivity for beta-1 receptors is relative, not absolute, and is reduced at higher doses, meaning beta-2 effects (e.g. on bronchial smooth muscle) can still occur. (1) (3)

What atenolol is used for

High blood pressure (hypertension)

Used alone or with other blood pressure medicines to lower blood pressure and reduce the risk of cardiovascular events such as stroke. (1)

Angina pectoris

Used for the long-term management of angina (chest pain) caused by coronary artery disease. (1)

Cardiac arrhythmias and after a heart attack (varies by country)

In some countries, atenolol is also used to help control certain abnormal heart rhythms, and in the acute and long-term management of a heart attack (myocardial infarction), always under close clinical supervision. (3) (7)

Before taking atenolol

Do not take / not appropriate for

  • Do not take atenolol if you have a very slow heart rate (sinus bradycardia), certain heart block conditions, uncontrolled heart failure, cardiogenic shock, very low blood pressure, or severe circulation problems in the limbs, unless your prescriber has specifically decided the benefits outweigh these risks. (all countries) (1) (3)
  • Do not take atenolol if you have had a serious allergic reaction to it or any of its ingredients. (all countries) (1)
  • Atenolol is generally avoided in people with a history of asthma or reversible airway obstruction unless your prescriber decides there is a compelling clinical reason and monitors you closely, since beta-blockers, including cardioselective ones, can still trigger severe bronchospasm in susceptible people. (United Kingdom, New Zealand) (3) (7)

Tell your clinician about

  • Any history of asthma, COPD, or other breathing problems.
  • Any history of heart failure, slow heart rate, or heart block.
  • Kidney problems -- atenolol is cleared by the kidneys and doses need adjustment.
  • Diabetes -- atenolol can mask some of the warning signs of low blood sugar.
  • Any history of severe allergic reactions -- beta-blockers can make these more severe and can make the usual emergency treatment less effective.
  • Pregnancy, plans for pregnancy, or breastfeeding.
  • All other medicines you take, especially other heart or blood pressure medicines such as verapamil, diltiazem, disopyramide, digoxin, or clonidine.
(1) (3)

How to take atenolol

  • Take atenolol at the same time each day, exactly as prescribed.
  • Swallow tablets whole; food can reduce how much atenolol your body absorbs, so try to take it consistently in relation to meals as your prescriber or pharmacist advises.
  • Do not stop taking atenolol or change your dose without your prescriber's guidance -- any change should be gradually planned by your clinician.
(1) (3)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6) (7)

Missed dose

If you miss a dose, take it as soon as you remember unless it is almost time for your next dose -- in that case, skip the missed dose. Do not take a double dose to make up for a missed one. If you are unsure, contact your prescriber or pharmacist.

Overdose

Seek urgent medical attention if you think you have taken too much atenolol, or if you have symptoms such as a very slow heartbeat, severe dizziness, fainting, or difficulty breathing. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Slow heart rate (bradycardia).

What to notice: Slow heart rate (bradycardia).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1) (3)

Cold hands and feet.

What to notice: Cold hands and feet.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1) (3)

Dizziness, tiredness, and fatigue.

What to notice: Dizziness, tiredness, and fatigue.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Low mood.

What to notice: Low mood.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Low blood pressure on standing (postural hypotension).

What to notice: Low blood pressure on standing (postural hypotension).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1) (3)

Nausea and diarrhoea.

What to notice: Nausea and diarrhoea.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Worsening angina, heart attack, or dangerous heart rhythm changes if atenolol is stopped suddenly — high caution

Symptoms: New or worsening chest pain, palpitations, or other signs of a heart problem after any change in your atenolol dose.

Action: Never stop taking atenolol or change your dose on your own. If your prescriber decides atenolol should be stopped, this is done gradually, usually over about 1-2 weeks, with close monitoring -- this is presented as a formal 'Serious Warnings and Precautions' notice in the current Canadian product monograph. Contact your prescriber promptly if you have any concerning symptoms, or seek emergency care for severe chest pain or a suspected heart attack. (4) (1) (3) (7)

Signs of worsening heart failure — emergency

Symptoms: Increasing shortness of breath, swelling in the legs or ankles, or sudden weight gain.

Action: Contact your prescriber promptly or seek emergency care if these symptoms are severe or rapidly worsening. (1) (7)

Severe allergic reaction — emergency

Symptoms: Swelling of the face, lips, tongue, or throat; difficulty breathing; widespread rash or hives. People on beta-blockers with a history of severe allergic reactions may have more severe reactions and standard adrenaline (epinephrine) treatment may be less effective.

Action: Seek emergency medical help immediately and tell emergency responders that you take a beta-blocker. (7) (3)

Very slow heart rate or breathing difficulty (asthma/COPD) — high caution

Symptoms: New wheeze, chest tightness, or shortness of breath, especially in people with a history of asthma or airway disease; or an unusually slow pulse.

Action: Contact your prescriber promptly, or seek emergency care for severe breathing difficulty. (3) (7)

Interactions

  • Verapamil or diltiazem (calcium-channel blockers) can increase the risk of a very slow heart rate or heart block when combined with atenolol. (1) (3)
  • Disopyramide combined with atenolol can cause severe slowing of the heart rate. (1)
  • Digoxin combined with atenolol can increase the risk of a very slow heart rate. (1)
  • Clonidine: if you take both clonidine and atenolol, your prescriber will manage stopping either medicine carefully and in a specific order, since stopping clonidine while still on a beta-blocker can cause a dangerous rebound rise in blood pressure. (1) (3)
  • NSAID pain relievers may reduce how well atenolol lowers blood pressure. (1) (3)
  • Insulin and other diabetes medicines: atenolol can mask some warning signs of low blood sugar (such as a fast heartbeat), and sulfonylurea medicines combined with atenolol may increase the risk of severe hypoglycaemia. (3)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Atenolol crosses the placenta and has been linked with babies being smaller than expected for their stage of pregnancy, particularly with use from the second trimester onward. Discuss the benefits and risks with your prescriber before continuing or starting atenolol in pregnancy. (1) (2) (3) (4) (5) (6) (7)

Breastfeeding

Atenolol passes into breast milk at higher levels than in the blood, and slow heart rate has been reported in breastfed infants, with premature or kidney-impaired infants at higher risk. Discuss with your prescriber before breastfeeding while taking atenolol. (1) (2) (3) (4) (5) (6) (7)

Children

Safety and effectiveness in children have not been established in the sources reviewed for this dossier; not authorised for paediatric use in some markets. (1) (2) (3) (4) (5) (6) (7)

Elderly

Older adults often need a lower dose, particularly if kidney function is reduced. (1) (2) (3) (4) (5) (6) (7)

Hepatic_impairment

No specific dose adjustment is described in the sources reviewed for this dossier; atenolol is mainly cleared by the kidneys rather than the liver. (1) (2) (3) (4) (5) (6) (7)

Renal_impairment

Atenolol is cleared by the kidneys, so people with reduced kidney function need a lower dose, decided by their prescriber based on kidney function tests. (1) (2) (3) (4) (5) (6) (7)

Source_ids

US-DAILYMED-ATENOLOL-2026,UK-EMC-ATENOLOL-2026,NZ-MEDSAFE-ATENOLOL-VIATRIS-2026 (1) (2) (3) (4) (5) (6) (7)

Monitoring

Before starting

  • Blood pressure and heart rate
  • Kidney function
  • Review of other heart/blood pressure medicines and any history of asthma or heart failure

During treatment

  • Regular blood pressure and heart rate checks.
  • Kidney function monitoring, especially in people with existing kidney problems or older adults.
  • Watching for signs of worsening heart failure, very slow heart rate, or breathing difficulty.
(1)

Storage

Store at room temperature (about 20-25C / 68-77F), in the original container, protected from light and moisture. Keep out of reach of children.

Study the drug class: Beta blockers

Professional information

Clinician-facing context only, sourced from current US FDA, UK SmPC, and New Zealand data sheet content reviewed for this dossier; verify against the current full label before prescribing.

United States

Indication: Hypertension, angina pectoris, acute myocardial infarction

Dose summary: Hypertension: 50 mg once daily initially, may increase to 100 mg once daily (doses above 100 mg provide no additional benefit). Angina: 50 mg once daily initially, may increase to 100 mg daily or 200 mg daily for optimal effect. Acute MI: IV 5-10 mg over 5 minutes, then 50 mg oral 10 minutes later, then 50 mg oral 12 hours after that, then 100 mg daily or 50 mg twice daily, under close monitoring.

Renal context: Creatinine clearance 15-35 mL/min/1.73m^2: maximum 50 mg daily. Below 15 mL/min/1.73m^2: maximum 25 mg daily. Haemodialysis: 25-50 mg after each dialysis session, under supervision. (1)

United Kingdom

Indication: Hypertension, angina, arrhythmias, acute myocardial infarction

Dose summary: Hypertension: 100 mg daily (range 50-100 mg). Angina: 100 mg once daily or 50 mg twice daily. Arrhythmias/MI: IV loading then oral maintenance, clinician-directed.

Renal context: Dose adjustment required when creatinine clearance is below 35 mL/min/1.73m^2. (3)

Mechanism of action

Hepatic guidance

Atenolol undergoes little hepatic metabolism; it is eliminated primarily by renal excretion, and its kinetics are not materially altered by hepatic impairment based on the sources reviewed.

Overdose note

Overdose can cause bradycardia, hypotension, bronchospasm, and acute cardiac failure; management is supportive and may include atropine, glucagon, or a beta-agonist under close monitoring, guided by the treating clinician. (1) (3)

Frequently asked questions

Is atenolol available in the US, UK, Europe, Canada, Australia, and New Zealand?

Yes, atenolol is an established, widely available generic medicine approved in all of these regions, originally marketed as Tenormin. (1) (5) (3) (4) (6) (7)

Can I just stop taking atenolol if I feel better?

No -- for many people, especially those with heart disease, stopping a beta-blocker like atenolol suddenly can cause a dangerous rebound of chest pain, a heart attack, or an abnormal heart rhythm. Any decision to reduce or stop atenolol should be made and supervised by your prescriber, usually with a gradual dose reduction over one to two weeks. (4) (1) (3)

Can people with asthma take atenolol?

Atenolol is more heart-selective than some older beta-blockers, but this selectivity is not complete, especially at higher doses, and it can still trigger breathing problems in people with asthma or airway disease. Your prescriber will weigh the risks and benefits carefully and monitor you closely if it is used. (3) (7)

What is the mechanism of action of atenolol?

Atenolol is a beta-1 selective (cardioselective) beta-adrenergic receptor blocking agent without membrane-stabilising or intrinsic sympathomimetic activity. Selectivity for beta-1 receptors is relative, not absolute, and is reduced at higher doses, meaning beta-2 effects (e.g. on bronchial smooth muscle) can still occur. (1) (3)

What is the generic name of Atenolol?

The generic name is atenolol. (1) (3)

What class of drug is atenolol?

Atenolol is classed as: Beta-1 selective (cardioselective) beta-blocker. (1) (3)

References

  1. ATENOLOL tablet -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information (Tenormin/generic atenolol) · United States · accessed 2026-07-29 · source 1
  2. TENORMIN (atenolol) tablets -- FDA label PDFU.S. Food and Drug Administration, drugs@fda label archive · United States · accessed 2026-07-29 · source 2
  3. Atenolol 100mg tablets -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Ipca Laboratories UK Ltd · United Kingdom · accessed 2026-07-29 · source 3
  4. TENORMIN (atenolol tablets BP) Product MonographHealth Canada product monograph, Searchlight Pharma Inc. · Canada · accessed 2026-07-29 · source 4
  5. Atenolol -- list of nationally authorised medicinal products (PSUSA/00000259)European Medicines Agency (EMA) · European Union · accessed 2026-07-29 · source 5
  6. Atenolol Sandoz / APX-Atenolol -- ARTG registrationTherapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-29 · source 6
  7. ATENOLOL VIATRIS New Zealand Data SheetMedsafe (New Zealand regulator), Viatris · New Zealand · accessed 2026-07-29 · source 7

Brand names by country

Single-ingredient atenolol names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • TENORMIN25 mg, 50 mg, 100 mg · upsher-smith laboratories, llc

United Kingdom

  • Atenolol (generic) (3)MHRA licensed emc smpc confirmed · 25 mg, 50 mg, 100 mg, oral solution · Ipca Laboratories UK Ltd (and other licence holders)

Canada

  • TENORMIN
  • MINT-ATENOL
  • APO-ATENOL

Australia

  • Atenolol Sandoz / APX-Atenolol / Tenelol (6)TGA ARTG registered confirmed · 50 mg, 100 mg · Sandoz Pty Ltd and other sponsors

New Zealand

  • Atenolol Viatris (7)Medsafe approved confirmed · 50 mg, 100 mg · Viatris
View brands in additional countries.

European Union

Atenolol (generic, nationally authorised in member states) (5)

This page provides general reference information about atenolol and is not a substitute for advice from the prescriber managing your treatment. All dosing and treatment decisions, including any change to your dose, should be made with your prescriber.

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