Consumer medicine information




Brand name


Active ingredient





Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Tensig.

What is in this leaflet

This leaflet answers some common questions about TENSIG. It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor has weighed the risks of you taking TENSIG against the benefits they expect it will have for you.

If you have any concerns about taking this medicine, ask your doctor or pharmacist.

Keep this leaflet with the medicine. You may need to read it again.

What TENSIG is used for

TENSIG belongs to a group of medicines called beta-blockers. It works by affecting the body's response to certain nerve impulses, especially in the heart. As a result, it decreases the heart's need for blood and oxygen and therefore reduces the amount of work the heart has to do. It widens the blood vessels in the body, causing blood pressure to fall. It also helps the heart to beat more regularly.

TENSIG is used to:

  • lower high blood pressure, which is also called hypertension
  • prevent angina (chest pain)
  • treat irregular heart rhythm or beat such as arrhythmia
  • treat or prevent heart attacks, or reduce your risk of heart complications following a heart attack
  • widen vessels in the heart which have narrowed

Everyone has blood pressure. This pressure helps get your blood all around your body. Your blood pressure may be different at different times of the day, depending on how busy or worried you are. You have hypertension (high blood pressure) when your blood pressure stays higher than is needed, even when you are calm and relaxed.

There are usually no symptoms of hypertension. The only way of knowing that you have hypertension is to have your blood pressure checked on a regular basis. You may feel fine and have no symptoms, but if high blood pressure is not treated, it can lead to serious health problems. TENSIG helps to lower your blood pressure.

Angina is a pain or uncomfortable feeling in the chest, often spreading to the arms or neck and sometimes to the shoulders and back. This may be caused by too little blood and oxygen getting to the heart. The pain of angina is usually brought on by exercise or stress, but can also occur at rest. TENSIG helps prevent angina. It is not used to relieve a sudden attack of angina.

Irregular heart beat (arrhythmia):
Irregular heart beat, also known as arrhythmia, means that there is a disturbance of the heart's normal rhythm or beat. Arrhythmias may be caused by a number of factors, including some heart diseases, an overactive thyroid gland, or chemical imbalances. TENSIG helps restore the heart's normal rhythm.

Reducing heart complications after heart attack:
After a heart attack there is a chance of developing arrhythmias or of further heart attacks occurring.

TENSIG helps prevent these conditions from occurring.

TENSIG may be either used alone or in combination with other medicines to treat your condition.

Ask your doctor if you have any questions about why this medicine has been prescribed for you. Your doctor may have prescribed it for another reason.

TENSIG is not recommended for use in children, as there have been no studies of its effects in children.

This medicine is available only with a doctor’s prescription.

There is no evidence that TENSIG is addictive.

Before you take it

When you must not take it

Do not take TENSIG if:

  1. you have an allergy to atenolol or any of the ingredients listed at the end of this leaflet, or to any other beta-blocker medicine.
  2. you have or have had asthma (difficulty in breathing, wheezing and coughing), bronchitis or other lung problems in the past.
  3. you have the following conditions:
  • a history of allergic problems, including hay fever. Symptoms of an allergy may include: rash, itching, watery eyes or sneezing.
  • low blood pressure (hypotension)
  • a very slow heart beat (less than 45-50 beats/minute)
  • certain other heart conditions such as heart failure
  • phaeochromocytoma (a rare tumour of the adrenal gland) which is not being treated already with other medicines.
  • you have too much acid in your blood, also called metabolic acidosis
  • a severe blood vessel disorder causing poor circulation in the arms and legs.
  • too much acid in your blood (metabolic acidosis)
  1. you are receiving:
  • certain anaesthetics for medical or dental procedures
  • certain heart medicines, called calcium channel blockers or calcium antagonists, such as verapamil
  • emergency treatment for shock or severely low blood pressure.
  1. you are pregnant or intend to become pregnant.
Like most beta-blocker medicines, TENSIG is not recommended for use during pregnancy.
  1. you are breast-feeding or plan to breast-feed.
TENSIG passes into breast milk and therefore there is a possibility that the breast-fed baby may be affected.

If you are not sure whether any of these apply to you, check with your doctor.

Do not take TENSIG if the packaging is torn or shows signs of tampering.

Do not take TENSIG if the expiry date (EXP) printed on the pack has passed. If you take this medicine after the expiry date has passed, it may not work as well.

If you are not sure whether you should start taking TENSIG, contact your doctor.

Before you start to take it

Tell your doctor if:

  1. you have any allergies to:
  • any other medicine including eye drops or other beta-blocker medicines
  • any other substances, such as foods, preservatives or dyes
  • insect stings
TENSIG may make allergies worse or make them harder to treat.
  1. you are pregnant or intend to become pregnant.
  2. you are breast-feeding or plan to breast-feed.
  3. you have or have had any medical conditions, especially the following:
  • heart problems
  • diabetes
  • an overactive thyroid gland called hyperthyroidism
  • kidney problems
  • any blood vessel disorders causing poor blood circulation in the arms and legs

If you have not told your doctor about any of the above, tell them before you take TENSIG.

Taking other medicines

Tell your doctor if you are taking any other medicines, including any that you buy without a prescription from your pharmacy, supermarket or health food shop.

Some medicines and TENSIG may interfere with each other. These include:

  • other beta-blocker medicine
  • medicines used to treat high blood pressure, angina or an irregular heart beat, such as verapamil or clonidine
  • medicines used to treat other heart problems
  • insulin and other medicines used to treat diabetes
  • medicines used to treat arthritis, pain, or inflammation, for example indomethacin and ibuprofen
  • medicines commonly used during surgery or in emergency situations such as dopamine, adrenaline, noradrenaline and certain anaesthetics.

These medicines may be affected by TENSIG, or may affect how well it works. You may need to take different amounts of your medicine, or you may need to take different medicines. Your doctor will advise you.

Your doctor and pharmacist may have more information on medicines to be careful with or avoid while taking TENSIG.

How to take it

How much to take and how to take it

Follow all directions given to you by your doctor and pharmacist carefully. They may differ from the information contained in this leaflet.

If you do not understand the instructions on the box, ask your doctor or pharmacist for help.

Certain people (eg. elderly patients or those with kidney problems) may require lower doses.

Adults – The usual daily dose is between 50 mg (1 tablet) up to 200 mg (4 tablets). If your dose is 100 mg or less, take your dose once a day. If your dose is greater than 100 mg, take half of your dose in the morning and the rest in the evening.

Angina or Arrhythmia (irregular heart beat):
Adults – The usual daily dose is between 50 mg (1 tablet) up to 100 mg (2 tablets), which can be taken as a single dose or half the dose in the morning and the rest in the evening.

Heart attack:
The usual dose is 50 mg (1 tablet) to 100 mg (2 tablets) daily for 1 – 3 years following a heart attack for 1 – 3 years.

The doses mentioned may be given after the condition (eg. arrhythmia, heart attack) is brought under control.

TENSIG is not recommended for children.

When to take it

Swallow TENSIG with a glass of water.

It does not matter if you take it before or after food.

Take your tablet(s) at the same time everyday.

How long to take it

TENSIG helps control your high blood pressure, angina and irregular heart beat, but does not cure it. Therefore TENSIG must be taken every day. Continue taking it for as long as your doctor prescribes.

Do not stop taking TENSIG without checking with your doctor. Your doctor may want you to gradually reduce the amount of TENSIG you are taking 2 weeks before stopping completely. This may help reduce the possibility of your angina worsening or other heart complications from occurring.

If you forget to take it

If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to. Otherwise, take it as soon as you remember, and then go back to taking your tablets as you would normally.

Do not take a double dose to make up for the dose that you missed.

If you have trouble remembering to take your medicine, ask your pharmacist for some hints.

If you take too much (overdose)

Immediately telephone your doctor or Poisons Information Centre (telephone 13 11 26), or go to casualty at your nearest hospital, if you think that you or anyone else may have taken too much TENSIG. Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention. Keep these telephone numbers handy.

If you take too much TENSIG, you may feel faint or dizzy or you may find it difficult to breathe.

While you are using it

Things you must do

Be sure to keep all of your doctor’s appointments so that your progress can be checked.

Tell all the doctors, dentists and pharmacists that are treating you that you are taking TENSIG.

If you become pregnant while taking TENSIG, tell your doctor immediately.

If you have a severe allergic reaction to foods, medicines or insect stings, tell your doctor immediately. If you have a history of allergies, there is a chance that TENSIG may cause allergic reactions to be worse and harder to treat.

If you are being treated for diabetes, make sure you check your blood sugar level regularly and report any changes to your doctor. TENSIG may change how well your diabetes is controlled. It may also cover up some of the symptoms of low blood sugar, called hypoglycaemia, such as fast heart beat. TENSIG may make low blood sugar last longer. Your doses of diabetic medicines, including insulin, may need to change.

If you have angina and continue to have angina attacks or have more of them while you are taking this medicine, tell your doctor. TENSIG is used to help prevent angina, so your angina attacks should become less severe and occur less often.

If you feel light-headed, dizzy or faint when getting out of bed or standing up, get up slowly. You may feel light-headed or dizzy when you begin to take TENSIG. This is because your blood pressure is falling suddenly. If this problem gets worse or continues, talk to your doctor.

To avoid symptoms of low blood pressure, here are some hints that may help:

  • stand up slowly from a sitting or lying position to help your body get used to the change in position and blood pressure
  • if you feel dizzy, sit or lie down until you feel better
  • if you feel faint, bend forward with your head between your knees
  • take extra care when exercising, driving or standing for long periods, especially in hot weather. Drink plenty if fluids, especially if you sweat a lot.

Make sure you drink enough water during exercise and hot weather when you are taking TENSIG, especially if you sweat a lot. If you do not drink enough water while taking TENSIG, you may feel faint, light-headed or sick. This is because your blood pressure is dropping suddenly. The recommended healthy minimum water intake is 6 – 8 glasses daily.

If you plan to have surgery (even at the dentist) that needs a general anaesthetic, tell your doctor or dentist that you are taking TENSIG. Your blood pressure may drop suddenly.

If you have to have any medical tests while you are taking TENSIG, tell your doctor. TENSIG may affect the results of some tests.

If you are about to be started on any new medicines, remind your doctor or pharmacist.

Tell any other doctors, dentists, and pharmacists who are treating you that you are taking TENSIG.

Things you must not do

Do not stop taking TENSIG without checking with your doctor. Your doctor may want you to gradually reduce the amount of TENSIG you are taking before stopping completely. This may help reduce the possibility of your angina worsening or other heart complications from occurring.

Do not give your medicine to anyone else even if they have the same condition as you.

Do not use it to treat any other complaints unless your doctor tells you to.

Things to be careful of

Be careful driving or operating machinery until you know how TENSIG affects you. As with other beta-blocker medicines, TENSIG may cause dizziness, light-headedness, tiredness and drowsiness in some people. Make sure you know how you react to TENSIG before you drive a car, operate machinery, or do anything else that could be dangerous if you are dizzy or lightheaded. If this occurs do not drive. If you drink alcohol, dizziness or light-headedness may be worse.

Dress warmly during cold weather, especially if you will be outside for a long time (for example, when playing winter sports). TENSIG, like other beta-blocker medicines, may make you more sensitive to cold temperatures, especially if you have blood circulation problems. Beta-blockers tend to decrease blood circulation in the skin, fingers and toes.

Side effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking TENSIG.

If you get any side effects, do not stop taking TENSIG without first talking to your doctor.

All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some of the side effects.

Ask your doctor or pharmacist to answer any questions you may have.

Tell your doctor if you notice any of the following and they worry you:

  • stomach upsets such as diarrhoea, constipation, abdominal pain or heartburn (indigestion)
  • dry mouth, change in taste sensation
  • dizziness, headache or buzzing or ringing in the ears
  • slow or irregular heart beat
  • dry eyes, problems with vision
  • runny or blocked nose
  • difficulty sleeping, nightmares, vivid dreams
  • skin reactions (e.g. rash, itching, worsening of psoriasis)
  • increased hair loss
  • tingling, 'pins and needles' or walking unsteadily
  • sexual problems

These are the more common side effects of TENSIG. For the most part these have been mild.

Tell your doctor immediately if you notice any of the following:

  • confusion or disorientation
  • depression or mood changes or a worsening of these
  • unusual thoughts, hallucinations (seeing, feeling or hearing things that are not there)
  • light-headedness or fainting which may be due to low blood pressure
  • yellowing of the skin and/or eyes (jaundice)

These are serious side effects. You may need urgent medical attention. Serious side effects are rare.

If any of the following happen, tell your doctor immediately or go to casualty at your nearest hospital:

  • shortness of breath, sometimes with tiredness, weakness and reduced ability to exercise, swelling of the feet or legs due to fluid buildup
  • chest pain, changes in heart rate (fast, slow or irregular), palpitations
  • swelling of the face, lips, tongue or throat which may cause difficulty in swallowing or breathing, which may be signs of a serious allergic reaction
  • chest tightness, wheezing, rattly breathing
  • bleeding or bruising more easily than normal

These are very serious side effects. You may need urgent medical attention or hospitalisation. These side effects are rare.

After using it


Keep your tablets in the pack until it is time to take them. If you take the tablets out of the pack they will not keep well.

Keep the tablets in a cool dry place where the temperature stays below 25 degrees Celsius. Protect from light.

Do not store TENSIG of any other medicine in the bathroom or near the sink.

Do not leave TENSIG in the car or on window sills. Heat and dampness can destroy some medicines.

Keep it where children cannot reach it. A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.


If your doctor tells you to stop taking TENSIG or the tablets have passed their expiry date, ask your pharmacist what to do with any that are left over.

Product description

What it looks like

TENSIG tablets are white, film coated, biconvex and round with a breakline on one face and plain on the other face..

TENSIG tablets are available in calendar packs or bottles (dispensing pack only) containing 30 tablets.


Each TENSIG tablet contains 50 mg atenolol as the active ingredient.

In addition, each tablet contains:

  • microcrystalline cellulose
  • pregelatinised maize starch,
  • sodium lauryl sulfate,
  • sodium starch glycollate,
  • colloidal anhydrous silica,
  • magnesium stearate,
  • Hypromellose
  • opadry white Y-1-7000B (containing hypromellose, titanium dioxide, Macrogol 400 and indigo carmine aluminium lake CI 73015).

TENSIG does not contain lactose, sucrose, gluten, tartrazine or any other azo dyes.


TENSIG is supplied in Australia by:

Arrow Pharma Pty Ltd
15-17 Chapel Street
Cremorne VIC 3121

The Australian Registration number for TENSIG 50 mg tablets is:
AUST R 147638
AUST R 77503 (bottle).

This leaflet was revised in November 2020.

Published by MIMS December 2020


Brand name


Active ingredient





1 Name of Medicine


2 Qualitative and Quantitative Composition

Tensig tablets: contain 50 mg of the active ingredient atenolol.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Tensig tablets are white, film coated, biconvex and round with a breakline on one face and plain on the other face.

4 Clinical Particulars

4.1 Therapeutic Indications

All grades of hypertension, including hypertension of renal origin.
Frequent disabling angina without evidence of cardiac failure.
Cardiac arrhythmias (maintenance treatment of supraventricular and ventricular arrhythmias including those associated with acute myocardial infarction).
Myocardial infarction: late intervention (β-blocker class effect greater than 12 hours after onset of chest pain).

4.2 Dose and Method of Administration




Therapy should be initiated with Tensig 50 mg daily. This may be increased each week in daily doses of 50 mg up to a maximum of 200 mg. Where patients are controlled on daily doses of 50 to 100 mg this may be given once daily. Doses above 100 mg daily should be given on a divided basis. Where necessary, a further reduction in blood pressure may be achieved by combining Tensig with other antihypertensive agents.
Patients can be transferred to Tensig from other antihypertensive treatments with the exception of clonidine (see Section 4.4 Special Warnings and Precautions for Use).

Angina pectoris.

Therapy should be initiated with Tensig 50 mg daily. This may be increased, if required, to 100 mg daily given as a single or divided dose. It is unlikely that additional benefit will be gained by increasing dose.

Cardiac dysrhythmias.

Having controlled the dysrhythmias with other intravenous agents a suitable oral maintenance dosage is 50 to 100 mg daily.

Acute myocardial infarction.

Late intervention (> 12 hours from onset of chest pain).

Atenolol has been shown to reduce infarct size, reduce the incidence of ventricular dysrhythmias, reduce the need for opiate analgesics and reduce mortality in the first 7 post-infarction days, most of the benefit being in the first 48 hours. Data from other β-blocker trials suggest that there is a significant reduction in mortality and a reduced incidence of nonfatal reinfarction if the β-blocker is continued for 1 to 3 years.
Hence, maintenance oral therapy of Tensig 50 mg daily is recommended for 1 to 3 years following myocardial infarction, beginning after early intervention with other agents, or immediately in those patients who present more than 12 hours after suffering an acute myocardial infarction.

Impaired renal function.

Since Tensig is excreted via the kidneys, dosage should be adjusted in cases of severe impairment of renal function. No significant accumulation of Tensig occurs at a creatinine clearance greater than 35 mL/minute/1.73 m2 (normal range is 100 to 150 mL/minute/1.73 m2). For patients with a creatinine clearance of 15 to 35 mL/min/1.73 m2 (equivalent to serum creatinine of 300 to 600 micromol/L) the oral dose should be 50 mg daily to 100 mg on alternate days. For patients with a creatinine clearance less than 15 mL/minute/1.73 m2 (equivalent to serum creatinine of greater than 600 micromol/L) the oral dose should be 50 mg on alternate days or 100 mg every fourth day.
Patients on haemodialysis should be given 50 mg orally after each dialysis; this should be done under hospital supervision as marked falls in blood pressure can occur.


Dosage requirements may be reduced especially in patients with impaired renal function.


There is no experience with the use of atenolol in children.

4.3 Contraindications


The β-adrenergic blockade of the smooth muscle of bronchi and bronchioles may result in an increased airways resistance. These drugs also reduce the effectiveness of asthma treatment. This may be dangerous in susceptible patients. Therefore, β-blockers are contraindicated in any patient with a history of airways obstruction or tendency to bronchospasm. Use of cardioselective β-blockers can also result in severe bronchospasm. If such therapy must be used, great caution should be exercised. Alternative therapy should be considered.
Congestive heart failure.
Allergic disorders (including allergic rhinitis) which may suggest a predisposition to bronchospasm.
Right ventricular failure secondary to pulmonary hypertension.
Significant right ventricular hypertrophy.
Sick sinus syndrome.
Sinus bradycardia (less than 45 to 50 beats/minute).
Second and third degree atrioventricular block.
Shock (including cardiogenic and hypovolaemia shock).
Anaesthesia with agents that produce myocardial depression (e.g. ether, chloroform, cyclopropane).
Hypersensitivity to atenolol.
Metabolic acidosis.
Severe peripheral arterial circulatory disturbances.
Untreated phaeochromocytoma.
Pregnancy and lactation (see Section 4.6 Fertility, Pregnancy and Lactation).

4.4 Special Warnings and Precautions for Use

Cardiac failure.

β-Blockade depresses myocardial contractility and may precipitate cardiac failure in some patients with a history of cardiac failure, chronic myocardial insufficiency or unsuspected cardiomyopathy as may occur in chronic alcoholism. In patients without a history of cardiac failure, continuing depression of the myocardium may lead to cardiac failure. If signs of cardiac failure present, the patients should be fully digitalised and/or given an ACE inhibitor or vasodilators with or without a diuretic and carefully monitored. If cardiac failure persists, the β-blocker should be withdrawn (see Abrupt withdrawal of therapy).


Although congestive heart failure has been considered to be a contraindication to the use of β-blockers, there is growing literature on the experimental use of β-adrenergic blocking drugs in heart failure. As further trials are needed to identify which patients are most likely to respond to which drugs, β-blockers should not normally be prescribed for heart failure outside of specialist centres.

Abrupt withdrawal of therapy.

Care should be taken if β-blockers have to be discontinued abruptly in patients with coronary artery disease. Severe exacerbation of angina and precipitation of myocardial infarction and ventricular arrhythmias have occurred following abrupt discontinuation of β-blockade in patients with ischaemic heart disease. Therefore, it is recommended that the dosage be reduced gradually over a period of about 8 to 14 days during which time the patient's progress should be reassessed. The drug may be temporarily reinstituted if the angina worsens. If the drug must be withdrawn abruptly, close observation is required. In the peri-operative period, β-blockers should not be withdrawn, unless indicated.

Allergic reactions.

While taking β-adrenoreceptor blocking drugs, patients with a history of anaphylactic reaction to a variety of allergens may have a more severe reaction on repeated challenge. Such patients may be unresponsive to the usual doses of adrenaline used to treat the allergic reactions.

First degree heart block.

Due to its negative effect on conduction time, caution must be exercised if atenolol is given to patients with first degree heart block.

Peripheral circulation.

β-blockade may impair the peripheral circulation and exacerbate the symptoms of peripheral vascular disease.

Prinzmetal angina.

There is a risk of exacerbating coronary artery spasm if patients with Prinzmetal or variant angina are treated with a β-blocker. If this treatment is essential, it should only be undertaken in a coronary or intensive care unit.

Euthyroid hyperthyroxinaemia.

The effects of β-blockers on thyroid hormone metabolism may result in elevations of serum free thyroxine (T4) levels. In the absence of any signs or symptoms of hyperthyroidism, additional investigation is necessary before a diagnosis of thyrotoxicosis can be made.

Use in acute myocardial infarction.

In addition to the contraindications listed (see Section 4.3 Contraindications), patients with the following conditions are not suitable for treatment with atenolol:
(a) Systolic blood pressure less than 120 mmHg (systolic blood pressure less than 120 mmHg in combination with a heart rate greater than 90 beats/min has a particularly poor prognosis).
(b) First degree A-V block. There is an increased incidence of cardiogenic shock (and need for inotropes), complete heart block and cardiovascular death in these patients, following atenolol.
Patients with atrial fibrillation following myocardial infarction, who were treated with atenolol, also had increased cardiovascular mortality compared with those not treated with atenolol. It is suggested that such patients be digitalised before atenolol therapy is commenced.


If a treated patient develops symptoms which may be attributable to a slow heart rate, the dose may be reduced.

Anaesthesia and the peri-operative period.

β-Blockade may have beneficial effects in decreasing the incidence of arrhythmias and myocardial ischaemia during anaesthesia and the postoperative period. It is currently recommended that maintenance β-blockade be continued peri-operatively. The anaesthetist must be made aware of β-blockade because of the potential for interactions with other drugs, resulting in severe bradyarrhythmias and hypotension, the decreased reflex ability to compensate for blood loss, hypovolaemia and regional sympathetic blockade, and the increased propensity for vagal induced bradycardia. Incidents of protracted severe hypotension or difficulty restoring normal cardiac rhythm during anaesthesia have been reported. Modern inhalational anaesthetic agents are generally well tolerated, although older agents (ether, cyclopropane, methoxyflurane, trichlorethylene) were sometimes associated with severe circulatory depression in the presence of β-blockade.


β-Blockers affect glucose metabolism and may mask some important premonitory signs of acute hypoglycaemia, such as tachycardia.
In patients with insulin or non-insulin dependent diabetes (NIDD), especially labile diabetes, or with a history of spontaneous hypoglycaemia, β-blockade may result in the loss of diabetic control and delayed recovery from hypoglycaemia. The dose of insulin or oral hypoglycaemic agent may need adjustment.

Other metabolic effects.

β-adrenoreceptors are involved in the regulation of lipid as well as carbohydrate metabolism. Some drugs affect the lipid profile adversely although the long-term clinical significance of this change is unknown and the effect appears to be less for drugs with intrinsic sympathomimetic activity.


In patients with this condition, an alpha-blocking drug (e.g. phentolamine/phenoxybenzamine) should be administered before the β-blocker to avoid exacerbation of hypertension.

Eye and skin reactions.

Various skin rashes and conjunctival xerosis have been reported with β-blockers. Cross reactions may occur between β-blockers, therefore, substitutions within the group may not necessarily preclude occurrence of symptoms.
During the long-term treatment with the β-blocking drug, practolol, a specific rash bearing a superficial resemblance to psoriasis was occasionally described. In a number of patients affected, this rash was accompanied by adverse effects on the eye (xerophthalmia and/or keratoconjunctivitis) of varying severity. This condition is called the oculomucocutaneous syndrome or practolol syndrome. In a few patients, these eye changes occurred independently of a skin rash. On rare occasions, serious otitis media, sclerosing peritonitis, pericarditis and pleurisy have been reported. Although the practolol syndrome has not been observed in patients taking other β-blockers, the possibility of such side effects occurring should be borne in mind.
More recently an association between Peyronie's disease (a fibrosing induration of the penis) and various β-blockers has been suggested but is not proven.

Allergic conditions.

These may be exaggerated by β-blockade (e.g. allergic rhinitis during the pollen season and allergic reactions to bee and wasp stings). β-blockers should be avoided if there is a risk of bronchospasm.


Since β-blockers may mask the clinical signs of developing or continuing hyperthyroidism, resulting in symptomatic improvement without any change in thyroid hormone status, special care should be exercised in those patients who are hyperthyroid and are also receiving β-blockers.

Significant cardiomegaly.

Use in renal impairment.

In patients with severe renal disease, haemodynamic changes following β-blockade may impair renal function further. β-Blockers which are excreted mainly by the kidney may require dose adjustment in patients with renal failure.

Use in the elderly.

See Section 4.2 Dose and Method of Administration.

Paediatric use.

No data available.

Effects on laboratory tests.

No data available. See Section 4.8 Adverse Effects (Undesirable Effects), Biochemical abnormalities.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Concomitant therapy with calcium antagonists.

The concomitant use of β-blockers and calcium antagonists with myocardial depressant and sinus node activity, e.g. verapamil, and to a lesser extent diltiazem, may cause hypotension, bradycardia and asystole, particularly in patients with impaired ventricular function and/or SA or AV conduction abnormalities. Extreme caution is required if these drugs have to be used together.
The dihydropyridine calcium antagonists (e.g. nifedipine) have a weaker myocardial depressant effect and can be administered cautiously with β-blockers. If excessive hypotension develops, the calcium antagonist should be stopped or the dosage reduced.

Antiarrhythmic drugs.

Class 1 anti-arrhythmic drugs (e.g. disopyramide) and the Class III agent, amiodarone may have potentiating effect on atrial conduction time and induce negative inotropic effect, this is seen less frequently with quinidine; Class IB agents, tocainide, mexiletine and lignocaine; Class IC agents, flecainide and propafenone (not available in Australia); and the Class IV antiarrhythmic agents.

Use of catecholamine depleting agents.

Concomitant use of drugs such as reserpine and guanethidine requires careful monitoring since the added effect of β-blockade may produce an excessive reduction of the resting sympathetic nervous tone.


Concurrent use of β-blockers and clonidine should be avoided because of the risk of adverse interaction and severe withdrawal symptoms. If administered concomitantly, the clonidine should not be discontinued until several days after the withdrawal of the β-blocker.

Insulin and oral hypoglycaemics.

(See Section 4.4 Special Warnings and Precautions for Use, Diabetes).


Anaesthetics such as methoxyflurane are contraindicated with Tensig (see Section 4.4 Special Warnings and Precautions for Use, Anaesthesia and the peri-operative period).

Digitalis/digitalis glycosides.

Digitalis/digitalis glycosides and β-blockers are commonly used together, although there have been reports of excessive bradycardia when β-blockers are used to treat digitalis intoxication.

Sympathomimetic agents.

Concomitant use of sympathomimetic agents, e.g. adrenaline, may counteract the effects of β-blockers.

Prostaglandin synthetase inhibitors.

Concomitant use of prostaglandin synthetase inhibiting drugs, e.g. ibuprofen and indomethacin may decrease the hypotensive effects of β-blockers.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category C)
β-adrenergic blocking agents may cause bradycardia in the fetus and newborn infant. During the final part of pregnancy and parturition, these drugs should, therefore, be given only after weighing the needs of the mother against the risk to the foetus.
Atenolol crosses the placental barrier in pregnant women, and under steady state conditions, maternal and foetal blood levels of atenolol are approximately equal.
No studies have been performed on the use of atenolol in the first trimester and the possibility of foetal injury cannot be excluded. Atenolol has been used under close supervision for the treatment of hypertension in the third trimester. Administration of atenolol for longer periods to pregnant women in the management of mild to moderate hypertension has been associated with intra-uterine growth retardation.
The use of Tensig in women who are or may become pregnant, requires that the anticipated benefit be weighed against the possible risks, particularly in the first and second trimesters. In general, β-blockers reduce placental perfusion, which has been associated with growth retardation, intrauterine death, abortion and early labour.
Atenolol has been shown to produce a dose related increase in embryo/foetal resorptions in rats at doses equal to or greater than 50 mg/kg. Although similar effects were not seen in rabbits, the compound was not evaluated in rabbits at doses above 25 mg/kg.
There is significant accumulation of atenolol in breast milk. Caution should be exercised when Tensig is administered to nursing women and the infant should be regularly assessed for signs of β-blockade.

4.7 Effects on Ability to Drive and Use Machines

Use is unlikely to result in any impairment of the ability of patients to drive or operate machinery. However, it should be taken into account that occasionally dizziness or fatigue may occur.

4.8 Adverse Effects (Undesirable Effects)

Adverse reactions reported in clinical trials of atenolol are mainly attributable to pharmacological actions. The adverse reactions listed below have been observed in patients in clinical trials who have received dosages of about 100 mg/day. It is not possible to give percentage incidences for each reaction, but if all mild and transient reactions are included as well as more serious ones, up to 10% of patients may experience some form of adverse reaction.

More common reactions.


Gastrointestinal disturbances including indigestion, constipation. Dry mouth.

Nervous system.

Fatigue, dizziness.


Wheezing. Bronchospasm. (See Section 4.3 Contraindications).

Less common reactions.

Biochemical abnormalities.

Increases in SGOT, blood urea and serum creatinine have been reported.


Bradycardia, left ventricular insufficiency, postural hypotension which may be associated with syncope, intermittent claudication may occur if already present, Raynaud's phenomenon, cold extremities, deterioration in heart failure, heart block.


Rash, alopecia, psoriasiform skin reactions, exacerbation of psoriasis.


Diarrhoea. Elevations of transaminase levels have been seen infrequently. Rare cases of hepatic toxicity including intrahepatic cholestasis have been reported.





Nervous system.

Vivid dreams, nightmares, paraesthesiae, tinnitus, vertigo, malaise, headache, insomnia, mood changes, confusion.


Dry eyes and visual disturbances.


Hallucinations, depression and psychoses.


Asthma, dyspnoea, nasal congestion.


Thrombocytopenia, purpura. An increase in ANA (Antinuclear Antibodies) has been observed, however, the clinical relevance of this is not clear.

Serious or life-threatening reactions.

Myocardial insufficiency may require treatment with digitalis and diuretics. Bradycardia may respond to atropine. Bronchospasm may be reversed with a β2-stimulant. Hypotension, if severe, may require use of a vasopressor.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at

4.9 Overdose


Overdosage has not been reported with atenolol but in overdosage with other β-blocking agents, severe bradycardia and hypotension are commonly found. Acute heart failure and bronchospasm may also occur.


Severe bradycardia.

Atropine 1 to 2 mg intravenously may be used to induce vagal blockade. If bradycardia persists, intravenous isoprenaline (25 microgram initially) or orciprenaline (0.5 mg given by slow intravenous injection) may be given. In refractory cases, the use of a cardiac pacemaker may be considered.


Severe hypotension should respond to a sympathomimetic amine such as noradrenaline. In refractory cases, the use of glucagon hydrochloride should be considered.


Therapy with a β2-stimulant such as salbutamol or terbutaline or therapy with aminophylline may be considered.

Acute cardiac failure.

Conventional therapy with digitalis, diuretics and oxygen should be instituted immediately. In refractory cases, the use of intravenous isoprenaline, followed if necessary by glucagon hydrochloride or intravenous aminophylline, should be considered.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Atenolol is a β-adrenoceptor blocking drug which acts preferentially on β-receptors in the heart. Selectivity decreases with increasing dose. It has little intrinsic sympathomimetic activity and no membrane stabilising activity. Atenolol is a racemic mixture and its activity resides in the S(-) enantiomer. It reduces raised blood pressure by an unknown mechanism and also inhibits exercise induced tachycardia and decreases plasma renin concentration. It causes slight airways obstruction but less than that seen with nonselective β-blockers. The inhibition of exercise induced tachycardia is correlated with blood levels but there is no correlation between plasma concentrations and antihypertensive effect. Atenolol is effective and well-tolerated in most ethnic populations although the response may be less in Afro-Caribbean black patients.
The possible mechanism of the antianginal activity of atenolol appears to be due to a reduction in left ventricular work and oxygen utilisation resulting (mainly) from the decrease in heart rate.
The antiarrhythmic effect of atenolol is apparently due to its antisympathetic effect. There is no evidence that membrane stabilising activity or intrinsic sympathomimetic activity are necessary for antiarrhythmic efficacy. By its antisympathetic effect, atenolol depresses sinus node function, atrioventricular node function and prolongs atrial refractory periods. It has no direct effect on electrophysiological properties of the His-Purkinje system.
Because of their negative ionotropic effects, beta-adrenoreceptor blocking agents should be avoided in uncontrolled heart failure.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties


Although the absorption of atenolol is variable and incomplete (40 to 60%), the virtual lack of hepatic metabolism results in relatively consistent systemic bioavailability compared to other β-blockers. Blood levels in humans peak two to four hours after a single 100 mg oral dose and are of the order of 0.4 to 0.9 microgram/mL. Blood levels are consistent and the levels after chronic oral administration are in good agreement with those predicted from single dose results.

Distribution and metabolism.

The drug is distributed throughout the body tissues and less than 10% of the dose is metabolised, the minor urinary metabolite identified being an hydroxylated derivative.


The main route of elimination is renal excretion. The plasma half-life, measured by blood level decay or urinary build up, is approximately 7 to 9 hours. In patients with impaired renal function there is a progressive prolongation of the half-life. In patients with normal renal function, the therapeutic effect (i.e. control of raised blood pressure) lasts for at least 24 hours following a 50 mg oral dose.

5.3 Preclinical Safety Data


No data available.


No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

The tablets also contain pregelatinised maize starch, microcrystalline cellulose, sodium lauryl sulfate, sodium starch glycollate, colloidal anhydrous silica, magnesium stearate, hypromellose and Opadry white Y-1-7000B (containing hypromellose, titanium dioxide, Macrogol 400 and indigo carmine aluminium lake CI 73015).

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Store below 30°C. Protect from light and moisture.

6.5 Nature and Contents of Container

They are available in bottles* (HDPE) and blister packs (PVC/PVdC/Al) of 30 tablets.
*The bottle packaging is for dispensing only and not to be supplied to a patient.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Atenolol is a β-adrenoceptor blocking agent structurally related to propranolol and differing from propranolol by substitution on the aromatic ring.

Chemical structure.

Atenolol is 2-[4-(2-hydroxy-3-isopropyl-aminopropoxy) phenyl] acetamide. The molecular formula and weight of atenolol are C14H22N2O3 and 266.3 respectively. The molecular structure is as below:

CAS number.


7 Medicine Schedule (Poisons Standard)

Prescription Only Medicine - S4.

Summary Table of Changes