Patient leaflet - Atenolol 50 mg tablets
1. What Atenolol is and what it is used for
The name of this medicine is Atenolol 25mg Tablets, Atenolol 50mg Tablets or Atenolol 100mg Tablets referred to as Atenolol throughout this leaflet.
Atenolol belongs to a group of medicines called ‘beta-blockers’.
Atenolol has been prescribed for one of the following:
- relieve angina pectoris (chest pain)
- control hypertension (high blood pressure)
- control irregular heart beat (arrhythmias)
- protect the heart from further damage in the early treatment or long term, after a heart attack (myocardial infarction)
It works by making your heartbeat more slowly and with less force.
2. What you need to know before you take Atenolol
Do not take Atenolol tablets and tell your doctor if:
- you are allergic to atenolol or any of the other ingredients of this medicine (listed in Section 6)
- you have second or third degree heart block (a condition which may be treated by a pacemaker)
- you have shock caused by heart problems
- you have heart failure which is not under control (this usually makes you breathless and causes your ankles to swell)
- you suffer with heart conduction or rhythm problems
- you have a slow heart rate
- you have low blood pressure
- you suffer from severe blood circulation problems (which may cause your fingers and toes to tingle or turn pale or blue)
- you suffer from an increased acidity of the blood (metabolic acidosis)
- you suffer from untreated phaeochromocytoma (high blood pressure due to a tumour near the kidney). If you are being treated for phaeochromocytoma, your doctor will give you another medicine, called an alphablocker, to take as well as Atenolol Tablets.
- you have or have had breathing problems such as asthma, difficulty breathing due to narrowing of the airways or reversible obstructive airways disease. Do not take this medicine if you have a history of wheezing or asthma. Consult your doctor or pharmacist first.
- you have recently received treatment or are being treated with intravenous verapamil or diltiazem.
Do not take Atenolol if any of the above apply to you. If you are not sure, talk to your doctor or pharmacist before taking Atenolol.
Warnings and precautions:
Talk to your doctor or pharmacist before taking Atenolol if you:
- have asthma, wheezing or any other similar breathing problems, or you get allergic reactions, for example to insect stings. If you have ever had asthma or wheezing, do not take this medicine without first checking with your doctor.
- have heart problems such as heart failure, untreated congestive heart failure, ischaemic heart disease, poor heart function (poor cardiac reserve), first degree heart block, slow heart beat or irregular heart beat
- suffer from blood circulation problems (which may cause your fingers and toes to tingle or turn pale or blue) or cramping pain causing limping (intermittent claudication)
- suffer with diabetes mellitus (low blood sugar levels may be hidden by this medicine). Your medicine may change how you respond to having low blood sugar. You may feel your heart beating faster. Atenolol could also increase the risk of severe hypoglycaemia when used with certain type of antidiabetic drugs called sulfonylureas (e.g. gliquidone, gliclazide, glibenclamide, glipizide, glimepiride or tolbutamide).
- have impaired liver or kidney function. You may need to have some check-ups during your treatment.
- are elderly
- suffer from a tight, painful feeling in the chest in periods of rest (Prinzmetal’s angina)
- have or have had psoriasis
- suffer from treated phaeochromocytoma (high blood pressure due to a tumour near the kidney)
- have high levels of thyroid hormone in the body (thyrotoxicosis). Your medicine may hide the symptoms of thyrotoxicosis.
- suffer from obstruction of the lungs or airways (chronic obstruction pulmonary disease)
- are about to undergo surgery where an anaesthetic will be used (including dentistry).
Other medicines and Atenolol
Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. This includes medicines obtained without a prescription or herbal medicines. This is because Atenolol can affect the way some other medicines work. Also some other medicines can affect the way Atenolol works.
Please tell your doctor or pharmacist if you are taking any of the following:
- clonidine (to treat high blood pressure or migraine) If you are taking clonidine and Atenolol tablets together, do not stop taking clonidine unless your doctor tells you to do so. If you have to stop taking clonidine, your doctor will give you careful instructions about how to do it.
- disopyramide, quinidine and amiodarone (to treat irregular heartbeat (arrhythmia))
- medicines to treat diabetes such as drugs called sulfonylureas (e.g.gliquidone, gliclazide, glibenclamide, glipizide,glimepiride or tolbutamide) including insulin
- Non-Steroidal Anti-Inflammatory Drug (NSAIDs) e.g. indomethacin, ibuprofen
- digitalis glycosides such as digoxin (to treat heart conditions)
- nifedipine, diltiazem, verapamil, prazosin, alfuzosin and terazosin (to treat high blood pressure)
- sympathicomimetic agents (decongestant, asthma or heart medicine)
- isoprenaline or dobutamine (widens blood vessels)
- tricyclic antidepressants e.g. amitriptyline
- barbiturates e.g. phenobarbital (used for insomnia, epilepsy or as an anaesthetic)
- phenothiazines e.g. chlorpromazine (for mental illness).
- baclofen (a muscle relaxant)
- adrenaline, also known as epinephrine (a medicine that stimulates the heart)
- contrast media (injection used with x-rays)
- ampicillin (used in urinary tract infections).
- anaesthetic drugs such as cyclopropane and trichlorethylene, lidocaine, procainamide and beta-adrenoceptor stimulants such as noradrenaline (norepinephrine).
- Calcium channel blockers – concomitant administration of dihydropyridine derivatives (e.g. nifedipine).
- Medicines to treat nose or sinus congestion or other cold remedies (including those you can buy in the pharmacy).
Pregnancy and breast-feeding
If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.
Atenolol with alcohol
You are advised to avoid alcohol whilst taking this medicine.
Driving and using machines
Atenolol may cause dizziness or tiredness. Make sure you are not affected before driving or operating machinery. If you feel dizzy or tired when taking this medicine, do not drive or use any tools or machines.
Anaesthetics and surgery
If you are going to have an operation or an anaesthetic, please tell your doctor or dentist that you are taking Atenolol as your heart beat might slow down too much and there may be an increased risk of developing low blood pressure.
Atenolol contains sodium
This medicine contains less than 1 mmol sodium (23mg) per tablet, that is to say essentially 'sodium free'.
3. How to take Atenolol
Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure.
Taking this medicine
- Swallow the tablets with a glass of water.
- You will be started on a low dose of Atenolol. This will gradually be increased by your doctor your condition is controlled.
The dose of Atenolol tablets can be varied by your doctor to suit your individual needs.
Do not alter the dose unless your doctor has told you to.
- Do NOT stop taking this medicine except on your doctor’s advice. In some cases, it may be necessary to stop taking your medicine gradually
- Try to take your tablet at the same time each day.
- If you have the impression that the effect of Atenolol is too strong or too weak, talk to your doctor or pharmacist.
How much to take – adults
High blood pressure (hypertension)
- 25mg tablets: the recommended dose is two to four tablets, once a day
- 50mg tablets: the recommended dose is one to two tablets, once a day
- 100mg tablets: the recommended dose is half to one tablet, once a day.
Angina (chest pain)
- 25mg tablets: the recommended dose is four tablets once a day OR two tablets twice a day.
- 50mg tablets: the recommended dose is two tablets once a day OR one tablet twice a day.
- 100mg tablets: the recommended dose is one tablet once a day OR half a tablet twice a day.
Irregular heartbeats (arrhythmias)
- 25mg tablets: the recommended dose is two to four tablets, once a day.
- 50mg tablets: the recommended dose is one to two tablets, once a day.
- 100mg tablets: the recommended dose is half to one tablet, once a day.
After a heart attack
Initial treatment will usually be by injection followed by subsequent oral treatment:
- 25mg tablets: two tablets 10 minutes after the injection and a further two tablets 12 hours later. Four tablets to be taken once a day thereafter.
- 50mg tablets: one tablet 10 minutes after the injection and a further tablet 12 hours later. Two tablets to be taken once a day thereafter.
- 100mg tablets: half a tablet 10 minutes after the injection and a further half tablet 12 hours later. One tablet to be taken once a day thereafter.
Patients with severe kidney problems
If you suffer with kidney problems the dose of Atenolol will be adjusted depending on how well your kidneys are functioning. Kidney function is calculated by testing your blood and urine. The recommended doses are:
- Mild to moderate kidney failure - 50mg a day or 100mg once every two days.
- Moderate to severe kidney failure - 50mg once every two days or 100mg once every four days.
If you are having dialysis treatment you will normally receive 50mg of Atenolol under hospital supervision, following each dialysis. Your doctor will let you know what your dose should be.
Elderly adults
Your doctor may prescribe you a lower dose to that described above if you are over 65 years of age, especially if you have kidney problems.
Children under 18 years
Not recommended.
If you take more Atenolol than you should
If you take more Atenolol than you should, talk to a doctor or go to a hospital straight away. Take the medicine pack with you. If possible, get someone else to drive you. Symptoms of an overdose include a slow or irregular heartbeat, low blood pressure, difficulty breathing due to fluid on the lungs, acute impaired heart function and shock, fainting.
If you forget to take Atenolol
If you forget to take a dose, take it as soon as you remember. However, if it is nearly time for the next dose, skip the missed dose. Then go on as before. Do not take a double dose to make up for a forgotten dose.
If you stop taking the Atenolol
Do not stop treatment early, especially if you have ischaemic heart disease. Talk to your doctor before you stop taking the tablets and follow their advice.
If you have any further questions on the use of this medicine, ask your doctor or nurse.
4. Possible side effects
Like all medicines, this medicine can cause side effects, although not everybody gets them.
Contact your doctor at once if you have the following:
- An allergic reaction such as itching, difficulty breathing or swelling of the face, lips, throat or tongue
- Altered numbers and types of your blood cells. If you notice increased bruising, nosebleeds, sore throats or infections, you should tell your doctor who may want to give you a blood test
- Breathing difficulties caused by narrowing of the airways in patients who have asthma or have had breathing problems
- Heart attack or shock.
Tell your doctor if you notice any of the following side effects, they get worse or you notice any not listed:
- Common (may affect up to 1 in 10 people): slow heartbeat, feeling sick, cold hands and feet, diarrhoea, tiredness, aching and tired muscles, GI disturbances such as stomach pains, heartburn and constipation
- Uncommon (may affect up to 1 in 100 people): increased levels of liver enzymes which may cause yellowing of the skin or eyes, abdominal swelling, itchy skin, tiredness., sleep disturbances such as difficulty sleeping
- Rare (may affect up to 1 in 1,000 people): disturbances in thinking (depression, mood swings, hallucinations, paranoia - psychoses), confusion, depression, reduced sexual potency in men (impotence), nightmares, headaches, dizziness, ‘pins and needles’ or tingling in the hands or feet, dry eyes, impaired vision, heart conduction problems (causing dizziness, abnormal heartbeat, fainting or tiredness), heart failure deterioration, Raynaud’s phenomenon (condition causing pain, numbness, coldness and blueness of the fingers), liver disorders, disorder of the skin especially a rash, hair loss (alopecia), worsening of psoriasis or skin reactions similar to psoriasis, insomnia, worsening of existing cramping pains causing limping (intermittent claudication), dry mouth, low blood pressure on standing, reduced numbers of platelets in your blood (this may make you bruise more easily), purplish marks on your skin, jaundice (causing yellowing of your skin or the whites of your eyes)
- Very Rare (may affect up to 1 in 10,000 people): Changes to some of the cells or other parts of your blood. Your doctor may take blood samples every so often to check whether Atenolol Tablets has had any effect on your blood
- Not known (frequency cannot be estimated from the available data): Lupus-like syndrome (a disease where the immune system produces antibodies that attacks mainly skin and joints)
- Other: symptoms of an overactive thyroid (increased heart rate and appetite, sweating, tremor, anxiety, weight loss and heat intolerance) or low blood sugar (muscle weakness, reduced movements, mental confusion and sweating) may be hidden by Atenolol.
Conditions that may get worse: If you have any of the following conditions, they may get worse when you start to take your medicine. This happens rarely affecting less than 1 in 1,000 people.
psoriasis (a skin condition), being short of breath or having swollen ankles (if you have heart failure), asthma or breathing problems, poor circulation.
Reporting of side effects
If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
By reporting side effects you can help provide more information on the safety of this medicine.
5. How to store Atenolol
- Keep this medicine out of the sight and reach of children.
- Do not store above 25°C.
- Store in the original container.
- Do not use this medicine after the expiry date which is stated on the carton after EXP. The expiry date refers to the last day of that month.
- Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.
6. Contents of the pack and other information
What Atenolol contains
- The active substance is atenolol. Each tablet contains 25mg, 50mg or 100mg of the drug substance atenolol.
- The other ingredients are heavy magnesium carbonate, maize starch, microcrystalline cellulose, magnesium stearate, sodium laurilsulfate, talc and gelatin.
What Atenolol Tablets look like and contents of the pack
- Atenolol Tablets are plain, white to off white, round, flat tablets with a score line on one side.
- Atenolol is only available from your pharmacist on prescription in blister pack sizes of 28, 100 or 250 tablets.
MA Holder: Steranco Healthcare UK Limited, John Eccles House, Robert Robinson Avenue, Oxford Science Park, Oxford, Oxfordshire, OX4 4GP, UK
Manufacturer: Medley Pharma Limited, Unit 2A, Olympic Way, Sefton Business Park, Bootle, Merseyside, L30 1RD, UK
Other sources of information
To request a copy of this leaflet in braille, please email medinfo@steranco.co.uk OR call +44(0)1865 684 083.
This leaflet was last revised in June 2026.