Atenolol

What is Atenolol?

Atenolol is a type medication known as a beta-blocker, and is used to treat high blood pressure (hypertension). Reducing blood pressure helps prevent strokes, heart attacks and kidney problems.

How does Atenolol work?

Atenolol is a type of beta blocker. When beta receptors in the heart and blood vessels are activated by adrenaline, blood pressure and heart rate rise. Beta blockers prevent adrenaline from activating beta receptors, causing blood vessels to relax. This reduces the heart’s demand for oxygen, helps lower blood pressure and reduces chest pain.

How long does Atenolol take to work?

It can take up to 2 weeks to feel the benefit of Atenolol. Atenolol needs to be taken regularly for best results, and does not work to treat chest pain as it occurs. Patients usually begin by taking a low dose, which is increased over the course of a few days. Taking the medication at the same time every day can help you remember. 

Active ingredients

The active ingredient in Atenolol tablets is Atenolol.

Inactive ingredients

The inactive ingredients of Atenolol tablets are Heavy Magnesium Carbonate, Maize Starch, Sodium Lauryl Sulphate, Gelatin, Magnesium Stearate, Microcrystalline Cellulose and Purified Talc. 

Please Note: Inactive ingredients may vary between different brands of generic drug.

How to take Atenolol

Atenolol tablets should be taken as instructed by your doctor. Treatment generally begins with the 25mg tablets, the lowest dose and is then gradually built up over the course of a few days. For treatment of high blood pressure, the usual adult dose is 100mg once a day. For treating chest pain or certain heart rhythm disorders, the adult dose can range from 50 - 100mg per day. A doctor may decide to lower the dosage for elderly patients or patients with severe kidney problems. This medicine must not be given to children.

Following a heart attack, the medication will initially be administered by intravenous injection, followed by a 50mg dose administered orally.   

Atenolol dosage

The usual dosage for treatment of hypertension in adults is 100 mg once daily, and 50-100 mg for treatment of angina pectoris (chest pain) and arrhythmias (heart rhythm disorders). Elderly patients, or patients with severe kidney disorders, may be prescribed a lower dosage by their doctor. Atenolol should never be given to children.

Can Atenolol tablets be crushed or split?

Atenolol can be crushed or split if necessary for easier administration, and can be taken with or without food.

What not to eat when taking Atenolol

It is best to avoid drinking apple or orange juice within 4 hours of taking Atenolol, as these can reduce your body’s ability to absorb the medication effectively. 

What should I do if I miss a dose of Atenolol?

If you miss a dose of Atenolol, you should take it as soon as you remember. However, if it is already time for your next dose, do not double the dose to make up for the missed one.

How to stop taking Atenolol

Atenolol should not be stopped suddenly. Your doctor will be able to advise you on how to stop taking Atenolol, which may have to be a gradual process over 7 - 14 days.

What time of day should I take Atenolol?

Atenolol can be taken at any time of the day as long as the time of day remains as consistent as possible. Taking Atenolol at the same time each day can also help you to remember to take the medication regularly. 

Atenolol side effects

If you experience any of the following serious side effects while taking Atenolol, you should go to the hospital immediately:

• Allergic reactions presenting as raised lumps on the skin or swelling of the face, lips, tongue or throat.
• Abnormal and/or erratic heartbeat, feeling of sudden fatigue, dizziness or fainting.
• Shortness of breath or swelling ankles.

Like al medication, a small percentage of patients will experience side effects when taking Atenolol. Common side effects (affecting up to 1 in 10 people) include:

• Slowing of the pulse: this is normal when taking Atenolol, but you should speak to your doctor immediately if you are concerned.
• Cold hands and feet.
• Nausea and/or diarrhoea.
• Fatigue and aching or tired muscles.

Up to 1 in 100 patients may also find that Atenolol disturbs their sleeping pattern. Further, rare side effects (affecting up to 1 in 1,000 people) include:

• Heart block: this can cause dizziness, abnormal heart beat, fatigue and fainting.
• Raynaud’s disease, characterised by numbness and spasm in the fingers, followed by sudden warmth and pain.
• Mood changes.
• Nightmares.
• Confusion, anxiety, changes in personality and/or hallucinations.
• Headaches and dizziness.
• Tingling or coldness in the hands.
• Impotence.
• Dry mouth or dry eyes.
• Disturbance of vision.
• Hair thinning.
• Skin rash.
• Reduced number of platelets in the blood, which can cause you to bruise more easily.
• Jaundice: yellowing of the skin or the whites of the eyes).

Extremely rarely, Atenolol can implement changes to some of the cells or other components of your blood. This only affects up to 1 in 10,000 people taking Atenolol, but your doctor may wish to take occasional blood samples to monitor the effect of Atenolol on your blood.  

Contraindications

Atenolol should not be taken if:

• You are allergic to Atenolol or to any other components of this medication.
• You have ever experienced heart failure, second- or third- degree heart block, very slow or uneven heartbeats, very low blood pressure or very poor circulation.
• You have a tumour called pheochromocytoma this is untreated.
• You have higher than normal levels of acid in your blood.

Before taking Atenolol, you should discuss with your doctor if:

• You have asthma or breathing problems, or experience allergic reactions to things such as insect stings.
• You have Prinzmetal’s angina.
• You have poor blood circulation or controlled heart failure.
• You have first-degree heart block.
• You have diabetes.
• You have thyrotoxicosis.
• You have problems with your kidneys.  

Drug interactions

Before taking Atenolol, it is important to let your doctor know if you are taking, have taken, or are about to start taking any other medicines, including medicines bought without a prescription. In particular, let your doctor know if you are planning to take Atenolol in combination with any of the following:

• Clonidine
• Verapamil, diltiazem or nifedipine
• Disopyramide
• Digoxin
• Adrenaline (also known as epinephrine
• Ibuprofen or indomethacin
• Insulin and oral medications used to treat diabetes
• Medicines, including those bought over the counter, used to treat nose or sinus congestion, coughs and colds.

Can I eat grapefruit when taking Atenolol?

As is the case with many medications, there is evidence that eating grapefruit or drinking grapefruit juice can increase the level of the medication in your blood. This is more of an issue if you are taking statins, however, you should still speak to your doctor for advice on eating grapefruit whilst taking Atenolol.

Atenolol and alcohol

While taking Atenolol, you should either avoid alcohol altogether, or limit the amount of alcohol you drink, as drinking alcohol can cause your blood pressure to drop too low.

Will Atenolol affect my libido?

In rare cases, Atenolol can cause a lowering of sex drive, impotence, or difficulty reaching orgasm. If you are experiencing any of these problems, speak to your doctor for advice.

Will Atenolol make me gain weight?

Beta blockers such as Atenolol can cause weight gain in some cases. If you feel that you are gaining significant amounts of weight as a result of taking Atenolol, seek advice from your doctor.

Alternatives to Atenolol

There are many different types of beta-blockers, which may have different effects on different people. If you experience troubling side effects of Atenolol, such as fatigue, it may be worth speaking to your doctor about switching to a different type of beta blocker. Alternatives to beta blockers include angiotensin receptor blockers and calcium-channel blockers, and are similarly effective in treating hypertension. You can read about the full range of treatments available from Dr Felix here.

Atenolol vs other beta-blockers

There are several different types of beta-blockers than can be used to treat high blood pressure (hypertension). Different people react in different ways to beta-blockers, and your doctor will be able to help you find the right one for you. Atenolol is the most commonly used beta blocker in treating hypertension and belongs to a group of beta-blockers called selective beta-1 receptor antagonists. This group works predominantly on beta-receptors in the heart and blood vessels. Selective beta-blockers are less likely to cause side effects and have less drug interactions and contraindications than nonselective beta-blockers prescribed for treatment of high blood pressure.  

How to switch blood pressure medication

You should always take blood pressure medication exactly as prescribed by your doctor and for as long as is required. You may need more than one prescription to manage your blood pressure and it can take some time to find out which medication is right for you. It is important to give each medication a trial period and allow your body to adjust speak to your doctor about any side effects you may be experiencing. Never stop or change a treatment without speaking to your doctor first.

Lifestyle changes to improve effects of Atenolol

While Atenolol is an effective treatment for high blood pressure, it should be accompanied by the appropriate lifestyle changes for best results. The following measures can be taken to help reduce blood pressure:

• Reduce the amount of salt in your diet
• Maintain a healthy and balanced diet in general
• Reduce the amount of alcohol you drink
• If you are overweight, work towards losing weight
• Exercise regularly
• Cut down on caffeine and stop smoking
• Try and get at least 6 hour sleep every night and avoid stress where possible.

Will Atenolol prevent a heart attack?

By reducing blood pressure, Atenolol helps lower the risk of heart attack. However, it is only effective as a treatment if accompanied by appropriate lifestyle changes. Patients at greater risk of experiencing a heart attack should make the following changes to their lifestyle:

• Maintaining a healthy diet that is low is salt
• Reduce the amount of alcohol and caffeine you drink
• Lose weight if you are overweight
• Stop smoking if you are a smoker
• Reduce the amount of salt in your diet
• Maintain a healthy and balanced diet in general
• Reduce the amount of alcohol you drink
• If you are overweight, work towards losing weight
• Exercise regularly
• Cut down on caffeine and stop smoking
• Try and get at least 6 hour sleep every night and avoid stress where possible.  

Why is Atenolol contraindicated with asthma?

If you are asthmatic or experience any similar breathing problems, you should speak with your doctor before taking Atenolol. Evidence has been found in the past that nonselective beta-blockers could increase airway resistance and put the patient at increased risk of asthma attacks. Newer, selective beta-blockers, such as Atenolol, are thought to be safe for asthmatic patients to take, but it is nevertheless important to get your doctors opinion on the matter before starting this medication.

Is Atenolol linked to increased diabetes risk?

Speculation on the link between beta-blockers and type-2 diabetes is twofold. First of all, the function of beta-blockers in slowing the heart rate can impair the patient's ability to recognise and respond to low blood sugar. Patients who are diabetic should be aware of this risk and speak to their doctor before starting beta-blockers. Secondly, there is evidence that by interfering with beta receptors in the body, beta-blockers can partially block the release of insulin in the pancreas, increasing the risk of developing type-2 diabetes. 

However, Atenolol is a selective beta-blocker which works on beta-1 receptors, found predominantly in the heart, and therefore is less likely to interact with the secretion and regulation of insulin in the pancreas. It is nevertheless important to be aware of the link between taking beta-blockers and type-2 diabetes, and speak to your doctor if you have concerns.   

Can I take Atenolol for anxiety?

Atenolol can be effective in treating the symptoms of anxiety, such as rapid heartbeat, shaking and blushing. Atenolol is particularly effective in treating social anxiety, as it is longer-acting than other beta-blockers and tends to have less side effects. However, stopping taking Atenolol as an anxiety treatment can cause a rise in blood pressure. Consult your doctor on how best to stop taking Atenolol.

Sources

• Patient information leaflet
• NHS > High Blood Pressure
• NHS > Grapefruit juice
• WebMD > Atenolol
• Healthline > Diabetes and Beta-blockers
• American Heart Association > Managing High Blood Pressure Medications
• PulmCCM > Beta-blockers and Asthma