Atenolol

What is atenolol?

Atenolol is a type of 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 and the heart rate to slow. This reduces the heart’s demand for oxygen, helps lower blood pressure and reduces chest pain.

How long does atenolol take to work?

Atenolol starts to work within 3 hours, however, it can take up to 2 weeks to reach its full benefit. 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 sometimes increased over the course of a few days or weeks. 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 in 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 drugs

How to take atenolol?

Atenolol tablets should be taken as instructed by your doctor. They can be taken with or without food and should be swallowed whole with a drink of water. 

For hypertension, treatment generally begins with 25–50 mg daily, which may be increased after two weeks if the desired effect is not achieved. The starting dose may differ for treating different conditions. You may be started on a lower dose if you have kidney problems or you are over the age of 65.

Atenolol dosage

The usual dosage for treatment of hypertension in adults is 25–50 mg once daily, with higher doses rarely required. For the treatment of angina pectoris (chest pain), the usual dose is 100 mg daily in 1 or 2 doses. You should always take the dose prescribed to you, and never alter this without first consulting your doctor.

Can atenolol tablets be crushed or split?

Atenolol can usually 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 the next day, 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, which may present 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 all 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 if you are concerned, or if this is accompanied by feeling breathless or faint
• Cold hands and feet
• Nausea
• Diarrhoea
• Fatigue
• Aching or tired muscles

Uncommon side effects (affecting up to 1 in 100 patients) include:

• Disturbed sleep

Rare side effects (affecting up to 1 in 1,000 people) include:

• Heart block (which can cause dizziness, abnormal heartbeat, tiredness or fainting).
• Raynaud’s phenomenon (numbness and spasm in your fingers when exposed to cold)
• Mood disturbance including depression
• Nightmares
• Confusion
• Anxiety
• Hallucinations
• Headache
• Dizziness
• Tingling in the hands
• Erectile problems
• Dry mouth
• Dry eyes
• Disturbances of vision
• Thinning of your hair
• 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)

Very rare side effects (affecting less than 1 in 10,000) people include:

• Changes to some of the cells or other components of your blood (e.g. antinuclear antibodies)

Contraindications

Atenolol should not be taken if you have:

• An allergy to atenolol or to any other components of this medication.
• Uncontrolled heart failure
• Second or third-degree heart block
• Sick sinus syndrome (a problem in the conduction pathways of the heart)
• Very low blood pressure
• Severe peripheral arterial disease (poor circulation)
• A tumour called pheochromocytoma which is untreated.
• Higher than normal levels of acid in your blood (metabolic acidosis
• Cardiogenic shock
• A heart rate less than 45 beats per minute

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
• Prinzmetal’s angina
• Poor blood circulation or heart failure
• First-degree heart block
• Diabetes
• Thyroid problems
• Kidney problems
• Liver problems
• Psoriasis

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:

• Any other medication designed to reduce your blood pressure e.g. Verapamil, Diltiazem or Nifedipine
• Clonidine
• 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?

There is no evidence of interaction between grapefruit and atenolol. Grapefruit however is known to interact with other medications such as statins, some ACE inhibitors, some calcium channel blockers and some angiotensin receptor blockers. Speak to your doctor or pharmacist for advice if you regularly consume grapefruit.

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 impotence, or difficulty achieving an erection. If you do experience this side effect, speak to your doctor for advice. There is limited evidence that atenolol affects libido.

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, 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, which 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 that 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 one of the most commonly used beta-blockers used 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 fewer drug interactions and contraindications than nonselective beta-blockers.

How to switch blood pressure medication?

You should always take blood pressure medicine 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 regime is right for you. It is important to give each medication a trial period and allow your body to adjust. You should speak to your doctor about any side effects you may be experiencing and 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 hours of sleep every night
• Avoid stress where possible

Will atenolol prevent a heart attack?

By reducing blood pressure, atenolol helps lower the risk of a heart attack. However, it is most 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 in salt
• Reduce the amount of alcohol and caffeine in the diet
• Losing weight if overweight
• Stopping smoking
• Reducing alcohol intake
• Exercise regularly
• Ensure good sleep 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 that works only 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 fewer side effects. You should only take atenolol for the indication it was prescribed for, and you should not suddenly stop atenolol.