Atenolol

High blood pressure and angina are long-term cardiovascular conditions that require consistent management to reduce the risk of serious events such as heart attack and stroke. Atenolol tablets are a prescription beta blocker used to treat hypertension, angina, and certain heart rhythm disorders in adults. Atenolol is one of the most widely prescribed beta blockers in the United Kingdom and has been used in cardiovascular therapy for several decades. It is taken once or twice daily depending on the condition being treated. A prescription can only be issued following a clinical consultation with a registered prescriber.

Atenolol tablets are an oral prescription medicine containing atenolol as the active ingredient. Atenolol belongs to the beta-adrenoceptor-blocking agent class of medicines, commonly referred to as beta blockers. It is a cardioselective beta blocker, meaning it acts preferentially on beta-1 receptors found in the heart, rather than on beta-2 receptors found in the airways and blood vessels. This selectivity means atenolol has less effect on the airways compared to non-selective beta blockers, though it is not entirely without effect on the lungs and must still be used with caution in patients with respiratory conditions.

Atenolol is licensed in the United Kingdom for the management of hypertension (high blood pressure), angina pectoris, cardiac arrhythmias (abnormal heart rhythms), and for early intervention in suspected or definite myocardial infarction (heart attack). It is available in three strengths: 25mg, 50mg, and 100mg tablets.

All clinical information on this page is drawn from the current UK Summary of Product Characteristics for atenolol tablets.

Important: Do not stop taking atenolol suddenly without speaking to your prescriber first. Abrupt withdrawal of a beta blocker can cause a rebound increase in heart rate and blood pressure, and may trigger or worsen angina or cause serious cardiac events. Your prescriber will advise on how to reduce your dose gradually if treatment needs to be stopped.

Atenolol works by selectively blocking beta-1 adrenoceptors in the heart. These receptors are normally stimulated by adrenaline and noradrenaline, which increase heart rate and the force of cardiac contraction. By blocking these receptors, atenolol reduces the speed and force of the heartbeat.

Effect on Blood Pressure

The reduction in heart rate and cardiac output lowers the pressure at which blood is pumped through the arteries, reducing systolic and diastolic blood pressure. With regular once-daily dosing, atenolol provides sustained antihypertensive effects throughout the day. It is effective as a standalone treatment for hypertension and is also used in combination with other antihypertensive medicines, particularly where additional blood pressure lowering is required.

Effect on Angina

In angina, the reduced heart rate and decreased force of contraction lower the oxygen demand of the heart muscle. This reduces the likelihood of the heart becoming starved of oxygen during physical activity or emotional stress, which is the trigger for angina episodes. By reducing the workload on the heart, atenolol decreases the frequency and severity of angina attacks and improves exercise tolerance in many patients.

Effect on Heart Rhythm

In cardiac arrhythmias, atenolol slows conduction through the atrioventricular node in the heart, which helps to regulate and slow an abnormally fast heart rate. It is used in conditions such as supraventricular tachycardia and in the rate control of atrial fibrillation. It may also be used following a heart attack to reduce the risk of further cardiac events.

Always take atenolol exactly as your prescriber instructs. The information below summarises key points from the current UK SmPC. Read the Patient Information Leaflet supplied with your medicine before starting treatment.

• Take atenolol once or twice daily as directed by your prescriber, depending on the condition being treated. For hypertension and angina, once-daily dosing is typical.
• Take atenolol at the same time each day. Consistent timing helps maintain a steady level of the medicine in your body.
• Atenolol can be taken with or without food.
• Swallow the tablet whole with a glass of water.
• If you miss a dose, take it as soon as you remember on the same day. If you only remember the following day, skip the missed dose and continue with your normal schedule. Do not take two doses on the same day.
• Never stop taking atenolol suddenly without medical advice. Abrupt withdrawal can cause a significant worsening of your condition. Your prescriber will advise on a gradual reduction if treatment needs to be stopped.

Atenolol tablets are available in three strengths through this service. The appropriate strength and dosing frequency will be determined by your prescriber based on the condition being treated, your age, kidney function, heart rate, and clinical response to treatment.

Atenolol 25mg Tablets

The 25mg tablet is a lower starting dose option, often used in older patients, patients with mild kidney impairment, or those who may be more sensitive to the effects of beta blockade. It provides a useful titration step when initiating treatment or adjusting the dose. Your prescriber will advise whether this strength is appropriate for your circumstances.

Atenolol 50mg Tablets

The 50mg tablet is the standard starting dose for most adults with hypertension or angina. For hypertension, 50mg once daily is the usual effective dose for many patients. For angina, 50mg once daily may be used initially, with the option to increase if symptoms remain inadequately controlled. This strength is also used in the management of cardiac arrhythmias, at doses determined by your prescriber.

Atenolol 100mg Tablets

The 100mg tablet is used when a higher dose is required for adequate blood pressure or angina control. For hypertension, doses above 100mg daily do not generally provide additional benefit. For angina, the prescriber may increase to 100mg once daily or prescribe 50mg twice daily depending on the clinical situation. All dose adjustments are made by your prescriber. Do not increase your dose without medical advice.

Like all medicines, atenolol can cause side effects, although not everyone experiences them. The information below is based on the current UK SmPC. Refer to the Patient Information Leaflet for the full list.

Common Side Effects (may affect up to 1 in 10 people)

• Bradycardia (a slow heart rate) - atenolol reduces heart rate as part of its therapeutic effect, but if the heart rate becomes very slow this may require a dose review
• Cold hands and feet, caused by reduced blood flow to the extremities
• Fatigue and tiredness
• Dizziness or lightheadedness, particularly when standing up quickly
• Gastrointestinal effects such as nausea, diarrhoea, or constipation

Uncommon Side Effects (may affect up to 1 in 100 people)

• Sleep disturbance, including vivid dreams or nightmares
• Mood changes, low mood, or depression
• Headache
• Dry eyes or visual disturbances
• Skin rash or itching

Serious Side Effects: Seek Urgent Medical Attention

Contact your prescriber or go to your nearest accident and emergency department promptly if you experience any of the following:

• A very slow or irregular heartbeat, or sudden worsening of breathlessness
• Significant worsening of breathlessness or wheezing, particularly if you have a respiratory condition - atenolol can occasionally worsen bronchospasm even at therapeutic doses
• Signs of heart failure such as increasing breathlessness, swelling of the ankles or legs, or rapid weight gain due to fluid retention
• Signs of a serious allergic reaction such as sudden swelling of the face, lips, tongue, or throat, difficulty breathing, or a severe skin reaction
• Worsening of symptoms of peripheral artery disease such as leg pain on walking

Report any suspected side effect to your prescriber or pharmacist or via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk.

Atenolol Tablets May Be Suitable If You:

• Are an adult with hypertension, angina, or a cardiac arrhythmia and have been assessed as requiring beta-blocker therapy
• Are already prescribed atenolol and require a repeat prescription through an online prescribing service
• Have hypertension and have not achieved adequate blood pressure control with other antihypertensive medicines alone

Atenolol Tablets Are Not Suitable If You:

• Have asthma or a history of bronchospasm - beta blockers, including cardioselective ones such as atenolol, can trigger bronchospasm and are contraindicated in patients with asthma
• Have severe bradycardia (very slow heart rate) or sick sinus syndrome
• Have second or third degree heart block (unless you have a pacemaker)
• Have cardiogenic shock or uncontrolled heart failure
• Have untreated phaeochromocytoma (a type of adrenal tumour)
• Have severe peripheral artery disease or Raynaud's phenomenon that is severely symptomatic
• Have metabolic acidosis
• Are under 18 years of age (this service is for adults only)

Cautions

Atenolol should be used with caution in patients with chronic obstructive pulmonary disease (COPD), as even cardioselective beta blockers may worsen airway obstruction in some patients. Caution is also required in patients with diabetes mellitus, as atenolol can mask some of the symptoms of hypoglycaemia (low blood sugar), particularly heart palpitations, which would normally alert a patient that their glucose is falling. Patients with kidney impairment may require a lower dose, as atenolol is primarily excreted by the kidneys. Your prescriber will take these factors into account during your consultation.

Important Drug Interactions

Atenolol can interact with a number of commonly prescribed medicines. Tell your prescriber about all medicines you take, including over-the-counter products and herbal supplements. The following interactions are of particular clinical importance:

• Calcium channel blockers of the verapamil or diltiazem type: combining these with atenolol can cause a significant and potentially dangerous slowing of the heart rate and reduction in blood pressure. This combination should generally be avoided unless under close specialist supervision.
• Other antihypertensive medicines: the blood pressure lowering effect of atenolol may be enhanced when taken with other medicines that reduce blood pressure.
• Antiarrhythmic medicines such as amiodarone: concurrent use may increase the risk of bradycardia and heart block.
• Clonidine: if both atenolol and clonidine are being stopped, atenolol should be withdrawn several days before clonidine to avoid a rebound rise in blood pressure.
• NSAIDs such as ibuprofen: these can reduce the antihypertensive effect of atenolol.
• Insulin and oral antidiabetic medicines: atenolol may mask some warning signs of hypoglycaemia. Blood glucose monitoring is particularly important in diabetic patients taking atenolol.

This is not a complete list of interactions. Your prescriber will carry out a full clinical assessment, including a review of your current medicines, before any prescription is considered.

Atenolol is a prescription-only medicine. The clinical consultation is the essential first step. A prescription will only be issued if a registered prescriber determines, based on their individual assessment of your circumstances, that atenolol is clinically appropriate for you.

During your online consultation with Pharmacy Planet, a registered prescriber will review your clinical information. This includes your blood pressure readings or cardiac history, current medicines, relevant medical conditions including any history of asthma, COPD, diabetes, or kidney disease, and any other factors relevant to safe prescribing of a beta blocker. Where you are seeking a repeat prescription, the prescriber will also assess whether your current treatment remains appropriate.

Not all consultations will result in a prescription being issued. The prescriber may recommend a different dose, a different medicine, or suggest that a face-to-face appointment with your GP is more appropriate. This process is designed to ensure your safety.

If you are already being managed for hypertension, angina, or a heart condition by your GP or a hospital team, please keep them informed of all medicines you are taking, including any prescribed through online services.

• Store below 25°C.
• Store in the original packaging to protect from light and moisture.
• Keep out of the sight and reach of children.
• Do not use after the expiry date printed on the packaging.
• Do not dispose of medicines via household waste or wastewater. Return unused or out-of-date tablets to your pharmacist for safe disposal.

Full storage instructions are provided in the Patient Information Leaflet supplied with your medicine.

The table below compares beta blocker tablets available at Pharmacy Planet. Beta blockers reduce heart rate and cardiac output to lower blood pressure. They differ in cardioselectivity, additional properties, and licensed indications.

Important: This comparison is for general information only and does not replace medical advice. A prescriber will decide which treatment is suitable for you following an online consultation.

Pharmacy Planet is a GPhC-registered pharmacy providing prescription medicines through a clinically led consultation process. Our registered prescribers and pharmacists are committed to patient safety, responsible prescribing, and accurate patient information. We follow GPhC standards, MHRA guidance, and ASA advertising regulations in all aspects of our service.

Our pharmacy team is available to answer questions about atenolol, beta-blocker therapy, or cardiovascular health more broadly. We are committed to providing clear, honest information to support you in managing your health safely and with confidence.

References

1. Electronic Medicines Compendium (eMC). Atenolol 25mg, 50mg and 100mg Tablets — Summary of Product Characteristics. https://www.medicines.org.uk/emc. Accessed August 2026.
2. National Institute for Health and Care Excellence (NICE). Hypertension in adults: diagnosis and management. NICE guideline NG136. https://www.nice.org.uk/guidance/ng136. Accessed August 2026.
3. NHS. Atenolol. https://www.nhs.uk/medicines/atenolol. Accessed August 2026.
4. Joint Formulary Committee. British National Formulary (BNF). Atenolol. BMJ Group and Pharmaceutical Press. https://bnf.nice.org.uk. Accessed August 2026.
5. Medicines and Healthcare products Regulatory Agency (MHRA). Yellow Card — report a side effect. https://yellowcard.mhra.gov.uk. Accessed August 2026.