Consumer medicine information

ATENOLOL RBX

Atenolol

BRAND INFORMATION

Brand name

Atenolol RBX Tablets

Active ingredient

Atenolol

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using ATENOLOL RBX.

What Is In This Leaflet

This leaflet answers some common questions about ATENOLOL RBX.

It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist.

This leaflet was last updated on the date at the end of this leaflet. More recent information may be available. The latest Consumer Medicine Information is available from https://www.ebs.tga.gov.au/ and may contain important information about the medicine and its use of which you should be aware.

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

This medicine may also be used in emergency situations where you may be unconscious. In this case, this leaflet may be given to you after the medicine has been used.

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 ATENOLOL RBX Is Used For

ATENOLOL RBX 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.

ATENOLOL RBX is used to:

  • lower high blood pressure, which is called hypertension
  • prevent angina
  • treat irregular heart rhythm or beat called arrhythmias
  • treat heart attacks, or reduce your risk of heart complications following a heart attack

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

ATENOLOL RBX may also be used in emergency situations or during surgery to treat a fast heart beat before, during or after surgery.

Hypertension:

All people have blood pressure. This pressure helps to push blood all around your body. Your blood pressure changes during the day, depending on how busy you are or how you are feeling. You have hypertension (high blood pressure) when your blood pressure stays higher than is needed, even when you are calm and relaxed. Regular blood pressure checks are the only way of knowing that you have hypertension. There are usually no symptoms of hypertension and you may feel fine. If hypertension is not treated, serious health problems such as stroke, heart disease and kidney failure may occur. ATENOLOL RBX helps to lower your blood pressure.

Angina:

Angina is a discomfort or pain felt in your chest. The pain may also be felt down your arms or neck and sometimes your shoulders and back. This may be caused by not enough oxygen or blood reaching areas of your heart. Angina pain is often brought on by exercise or stress. ATENOLOL RBX is used to prevent angina. It is not used to relieve a sudden attack of angina.

Irregular heart beat (arrhythmia):

A number of factors such as some heart diseases, an over active thyroid gland or chemical imbalances may cause your heart to have an irregular heart beat or rhythm. ATENOLOL RBX helps restore your heart's normal rhythm.

Reducing heart complications after heart attack:

After a heart attack, you may have complications such as an irregular heart beat or an increased chance of having another heart attack. ATENOLOL RBX helps to prevent these complications from occurring.

Ask your doctor if you have any questions about why it has been prescribed for you.

Your doctor may have prescribed ATENOLOL RBX for another reason. ATENOLOL RBX is not recommended for use in children, as there have been no studies of its effects in children. There is no evidence that ATENOLOL RBX is addictive.

Before You Take ATENOLOL RBX

When you must not take it

Do not take ATENOLOL RBX if:

  1. you have or have had asthma (difficulty in breathing, wheezing and coughing), bronchitis or other lung problems in the past.
  2. you have the following conditions:
  • a history of allergic problems, including hayfever. Symptoms of an allergy may include: rash, itching, watery eyes or sneezing.
  • a very slow heart beat (less than 45-50 beats/minute)
  • a severe blood vessel disorder causing poor circulation in the arms and legs
  • certain other heart conditions
  • phaeochromocytoma (a rare tumour of the adrenal gland) which is not being treated with other medicines
  • low blood pressure (hypotension)
  • too much acid in your blood (metabolic acidosis)
  1. you are receiving:
  • certain anaesthetics for medical dental procedures
  • emergency treatment for shock or severely low blood pressure
  1. you have an allergy to ATENOLOL RBX or any of the ingredients listed at the end of this leaflet, or to any other beta-blocker medicine.
  2. you are pregnant, intend to become pregnant, are breast feeding or intend to breast feed.
    Your doctor will discuss the possible risks and benefits of using ATENOLOL RBX during pregnancy and breast feeding. ATENOLOL RBX passes into breast milk and may therefore affect the breast-fed baby.

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

Do not use ATENOLOL RBX if the package is torn or shows signs of tampering.

Do not use ATENOLOL RBX if the expiry date (EXP) printed on the pack has passed.

This medicine may not work as well after this date.

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
    ATENOLOL RBX may make allergies worse or make them harder to treat.
  1. you have or have had a history of any of the following conditions:
  • heart problems
  • diabetes
  • an over active thyroid gland called hyperthyroidism
  • kidney problems
  • circulation problems

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

Taking other medicines

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

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

  • other beta-blocker medicines
  • medicines used to treat high blood pressure or angina
  • medicine used to treat heart problems
  • insulin and tablets used to treat diabetes
  • medicines used to treat arthritis, pain, or inflammation

If any of these medicines and ATENOLOL RBX are taken together, it may affect how each of them work. You may need to take different amounts of your medicine, or you may need to take different medicines. Your doctor will advise you on which medicines to be careful with or to avoid while taking ATENOLOL RBX.

How To Take ATENOLOL RBX

How much to take

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 label, ask your doctor or pharmacist for help.

Hypertension:
The usual dose is from 50 mg up to 200 mg of ATENOLOL RBX (one to four tablets) daily.

If your dose is 100 mg or less, take it once a day. If you need to take more than 100 mg, take half of your dose in the morning and the other half in the evening.

Angina or Irregular Heart Beat:
The usual dose is from 50 mg up to 100 mg (one to two tablets) taken as a single dose or half the dose in the morning and half at night.

Heart attack:
The usual dose is 50 mg of ATENOLOL RBX daily.

Certain people e.g. the elderly or those with kidney problems, may require a lower dose.

When to take it

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

Swallow ATENOLOL RBX with a glass of water, during or immediately after a meal.

Take your tablet at the same time everyday.

This will help you remember when to take the tablet.

How long to take it

Take ATENOLOL RBX every day.

Continue taking ATENOLOL RBX until your doctor advises you to stop.

It helps to treat high blood pressure, irregular heart beat, heart attacks and prevent angina but does not cure it.

Do not stop taking ATENOLOL RBX without checking with your doctor.

Your doctor may want you to gradually reduce the amount of ATENOLOL RBX you are taking. This should take place over a period of about 2 weeks before stopping completely. Do not stop suddenly as this may worsen your condition.

If you forget to take it

If it is less than six hours from when you missed your dose, take it as soon as you remember, and then go back to taking your tablets at the same time you would normally.

If it is more than six hours since your last dose, skip the dose you missed and take your next dose when you would normally.

Do not take a double dose of ATENOLOL RBX 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 the Poisons Information Centre (telephone 13 11 26), or go to Accident & Emergency at your nearest hospital, if you think that you or anyone else may have taken too much ATENOLOL RBX. 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 ATENOLOL RBX, you may feel faint or dizzy or you may find it difficult to breathe.

While You Are Taking ATENOLOL RBX

Things you must do

Attend 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 ATENOLOL RBX.

Tell your doctor immediately if you become pregnant while taking ATENOLOL RBX.

Immediately tell your doctor if you have an allergic reaction to any foods, medicines or insect stings.

ATENOLOL RBX can cause allergic reactions to be worse and harder to treat.

If you have diabetes, check your blood sugar level regularly and report any changes to your doctor.

ATENOLOL RBX may affect your diabetes. It may hide the symptoms of low blood sugar levels, such as a fast heart beat. It may also take longer for your blood sugar level to get back to normal even if you follow the usual treatment for diabetes. Your diabetic medicines may have to be changed or the doses adjusted.

If you continue to have angina attacks, or have more of them whilst taking ATENOLOL RBX, tell your doctor.

ATENOLOL RBX 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 after taking ATENOLOL RBX. This is because your blood pressure is falling suddenly.

If this problem gets worse or continues, talk to your doctor.

To help your body get used to the change in blood pressure, you may find the following hints useful:

  • Stand up slowly when getting up from a chair or bed. This will allow 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, sit down and put your head between your knees.

Drink lots of water when exercising and during hot weather when taking ATENOLOL RBX, especially if you sweat a lot.

If you do not drink enough water while taking ATENOLOL RBX, you may feel faint, light-headed or sick. The recommended healthy minimum water intake is 6-8 glasses a day.

If you are having surgery (even at the dentist), tell your doctor or dentist that you are taking ATENOLOL RBX.

ATENOLOL RBX may affect some of the medicines used during surgery.

If you have to have any medical tests while you are taking ATENOLOL RBX, tell your doctor.

ATENOLOL RBX may affect the results of some tests.

Things you must not do

Do not stop taking ATENOLOL RBX without checking with your doctor.

Do not take any new medicines with ATENOLOL RBX, unless your doctor has told you to.

Do not give ATENOLOL RBX to anyone else, even if they have the same condition as you.

Do not use ATENOLOL RBX to treat any other complaint unless your doctor tells you to.

Things to be careful of

Take care driving or operating machinery until you know how ATENOLOL RBX affects you.

ATENOLOL RBX may cause dizziness, fatigue, light-headedness or faintness in some people.

Be careful not to over exercise when you first start taking ATENOLOL RBX.

It helps prevent angina resulting from physical activity and exercise. You may be tempted to exercise too much. Talk to your doctor about how much exercise you can do.

Dress warmly during cold weather, especially if you will be outside for a long time (for example, when playing or watching sport in winter).

ATENOLOL RBX, like other beta-blocker medicines, may make you more sensitive to cold temperatures, especially if you have 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.

ATENOLOL RBX, even if you think the problems are not connected with the medicine.

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

Like other medicines ATENOLOL RBX can cause some side effects. If they occur, most are likely to be minor and last only a short time. However, some may be serious and need medical attention.

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
  • skin reactions (e.g. rash, itching, worsening of psoriasis)
  • cold fingers and toes
  • increased hair loss
  • tingling, 'pins and needles' or walking unsteadily
  • sexual problems

For the most part these side effects 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 accident and emergency at your nearest hospital:

  • wheezing, chest tightness or difficulty breathing
  • unexplained bruising
  • swelling of the face, lips or throat

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

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

Some people may get other side effects while taking ATENOLOL RBX.

Do not be alarmed by this list of possible side effects. You may not experience any of them.

After Using ATENOLOL RBX

Storage

Keep your tablets in a cool, dry place where the temperature will stay below 25°C. Protect from light. Keep your tablets in the pack until it is time to take them.

If you take the tablets out of the pack they may not work as well.

Do not keep ATENOLOL RBX in the bathroom or near a sink.

Do not leave ATENOLOL RBX in the car or on window sills.

Heat and dampness can destroy some medicines.

Keep this medicine out of reach of children.

A locked cupboard which children cannot reach is a good place to store medicines.

Disposal

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

Product Description

What ATENOLOL RBX tablets look like

ATENOLOL RBX Tablets 50 mg are white to off-white, circular biconvex film coated tablets with “50” embossed on one side and break line on other side. ATENOLOL RBX 50 mg tablets come in blister packs of 30 tablets.

Ingredients

Active ingredient:
ATENOLOL RBX 50 mg tablets - atenolol 50 mg

Inactive ingredients:

  • Magnesium stearate
  • Maize starch
  • Sodium lauryl sulphate
  • Colloidal anhydrous silica
  • Sodium starch glycollate type A
  • Magnesium carbonate - heavy
  • Hypromellose
  • Macrogol 6000
  • Titanium dioxide
  • Purified talc

ATENOLOL RBX does not contain lactose, sucrose or gluten.

Sponsor

Ranbaxy Australia Pty Ltd.
9-13 Waterloo Road
Macquarie Park NSW 2113

Australian Register Numbers

  • ATENOLOL RBX 50 mg - 197759

This leaflet was prepared in March 2015.

BRAND INFORMATION

Brand name

Atenolol RBX Tablets

Active ingredient

Atenolol

Schedule

S4

 

Name of the medicine

Atenolol.

Excipients.

Magnesium stearate, maize starch, sodium lauryl sulfate, anhydrous colloidal silica, sodium starch glycollate type A, heavy magnesium carbonate, hypromellose, macrogol 6000, titanium dioxide, purified talc.

Description

Chemical name: (RS)-4-(2-hydroxy-3-isopropylaminopropoxy) phenyl]acetamide. C14H22N2O3. MW: 266.3. CAS: 29122-68-7. Atenolol is a white or almost white powder, sparingly soluble in water, soluble in ethanol, slightly soluble in methylene chloride and practically insoluble in ether.
Beta-adrenoreceptor blocking agent structurally related to propranolol and differing from it by substitution on the aromatic ring.

Pharmacology

Atenolol is a beta-adrenoreceptor blocking drug which acts preferentially on beta-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 beta-blockers. The inhibition of exercise induced tachycardia is correlated with blood levels but there is no correlation between plasma concentrations and antihypertensive effect. Atenolol RBX 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 and contractility.
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 inotropic effects, beta-adrenoreceptor blocking agents should be avoided in uncontrolled heart failure.

Pharmacokinetics.

Although absorption of atenolol is variable and incomplete (40 to 60%) the virtual lack of liver metabolism results in a relatively consistent systemic bioavailability compared to other beta-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. The drug is distributed throughout the body tissues and less than 10% of the dose is metabolised, the minor urinary metabolite identified being a 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 (that is, control of raised blood pressure) lasts for at least 24 hours following a 50 mg oral dose.

Indications

Atenolol is indicated in the management of the following.
1. All grades of hypertension, including hypertension of renal origin.
2. Frequent disabling angina without evidence of cardiac failure.
3. Cardiac arrhythmias (acute treatment of supraventricular and ventricular arrhythmias including those associated with acute myocardial infarction).
4. Myocardial infarction, late intervention (beta-blocker class effect greater than 12 hours after onset of chest pain).

Contraindications

1. Bronchospasm. Beta-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, beta-blockers are contraindicated in any patient with a history of airways obstruction or tendency to bronchospasm. Use of cardioselective beta-blockers can also result in severe bronchospasm. If such therapy must be used, great caution should be exercised. Alternative therapy should be considered.
2. Congestive heart failure.
3. Allergic disorders (including allergic rhinitis) which may suggest a predisposition to bronchospasm.
4. Right ventricular failure secondary to pulmonary hypertension.
5. Significant right ventricular hypertrophy.
6. Sick sinus syndrome.
7. Sinus bradycardia (less than 45 to 50 beats/minute).
8. Second and third degree A-V block.
9. Shock (including cardiogenic and hypovolaemic shock).
10. Anaesthesia with agents that produce myocardial depression (e.g. ether, chloroform, cyclopropane).
11. Hypersensitivity to the drug.
12. Hypotension.
13. Metabolic acidosis.
14. Severe peripheral arterial circulatory disturbances.
15. Untreated phaeochromocytoma.
16. Pregnancy and lactation. (See Precautions, Use in pregnancy and Use in lactation.)

Precautions

Cardiac failure.

Beta-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 beta-blocker should be withdrawn. (See Precautions, Abrupt withdrawal of therapy.)

Note.

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

Abrupt withdrawal of therapy.

Care should be taken if beta-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 beta-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 reinstituted temporarily if the angina worsens. If the drug must be withdrawn abruptly, close observation is required. In the perioperative period, beta-blockers should not be withdrawn, unless indicated.

History of anaphylactic reaction.

While taking beta-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.

Beta-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 beta-blocker. If this treatment is essential, it should only be undertaken in a coronary or intensive care unit.

Euthyroid hyperthyroxinaemia.

The effects of beta-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 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.

Bradycardia.

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

Anaesthesia and the perioperative period.

Beta-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 of beta-blockade be continued perioperatively. The anaesthetist must be made aware of beta-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 beta-blockade.

Diabetes.

Beta-blockers affect glucose metabolism and may mask some important premonitory signs of acute hypoglycaemia, such as tachycardia.
In patients with insulin or noninsulin dependent diabetes, especially labile diabetes, or with a history of spontaneous hypoglycaemia, beta-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.

Beta-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.

Phaeochromocytoma.

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

Eye and skin reactions.

Various skin rashes and conjunctival xerosis have been reported with beta-blockers. Cross reactions may occur between beta-blockers, therefore, substitutions within the group may not necessarily preclude occurrence of symptoms.
During the long-term treatment with the beta-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, serous otitis media, sclerosing peritonitis, pericarditis and pleurisy have been reported. Although the practolol syndrome has not been observed in patients taking other beta-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 beta-blockers has been suggested but is not proven.

Allergic conditions.

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

Hyperthyroidism.

Because beta-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 beta-blockers.

Renal disease.

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

Significant cardiomegaly.


Use in pregnancy.

(Category C) Beta-adrenergic blocking agents may cause bradycardia in the foetus and newborn infant. During the final part of pregnancy and parturition, these drugs should therefore only be given 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 intrauterine growth retardation. The use of atenolol 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.
Atenolol has been shown to produce a dose related increase in embryofoetal 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.

Use in lactation.

There is significant accumulation of atenolol in breast milk. Caution should be exercised when atenolol is administered to nursing women and the infant should be regularly assessed for signs of beta-blockade.

Effect on ability to drive or operate machinery.

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.

Interactions

Concomitant therapy with calcium antagonists.

The concomitant use of beta-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 S-A or A-V 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 beta-blockers. If excessive hypotension develops, the calcium antagonist should be stopped or the dosage reduced.

Antiarrhythmic drugs.

Class 1 antiarrhythmic 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 propaferone (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 beta-blockade may produce an excessive reduction of the resting sympathetic nervous tone.

Clonidine.

Concurrent use of beta-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 beta-blocker.

Insulin and oral hypoglycaemics.

(See Precautions, Diabetes.)

Anaesthetics.

Anaesthetics, such as methoxyflurane, are contraindicated with atenolol (see Precautions, Anaesthesia and the perioperative period).

Digitalis/ digitalis glycosides.

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

Sympathomimetic agents.

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

Prostaglandin synthetase inhibitors.

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

Adverse 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 per 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.

Dry mouth, gastrointestinal disturbance including indigestion, constipation.

Nervous system.

Fatigue, dizziness.

Respiratory.

Wheezing, bronchospasm. (See Contraindications.)

Less common reactions.

Biochemical abnormalities.

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

Cardiovascular.

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.

Dermatological.

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

Gastrointestinal.

Diarrhoea, elevations of transaminase levels have been seen infrequently, rare cases of hepatic toxicity including intrahepatic cholestasis have been reported.

Genitourinary.

Impotence.

Musculoskeletal.

Ataxia.

Nervous system.

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

Ocular.

Dry eyes, visual disturbances.

Psychiatric.

Hallucinations, depression, psychoses.

Respiratory.

Asthma, dyspnoea, nasal congestion.

Haemopoietic.

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 beta2-stimulant. Hypotension, if severe, may require use of a vasopressor.

Dosage and Administration

Oral dosage.

Adults.

Hypertension.

Therapy should be initiated with 50 mg of atenolol 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 atenolol with other antihypertensive agents.
Patients can be transferred to atenolol from other antihypertensive treatments with the exception of clonidine. (See Precautions.)

Angina pectoris.

Therapy should be initiated with 50 mg of atenolol 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, atenolol given orally at a dosage of 50 to 100 mg daily will help maintain control.

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 postinfarction days, most of the benefit being in the first 48 hours. Data from other beta-blocker trials suggest that there is a significant reduction in mortality and a reduced incidence of nonfatal reinfarction if the beta-blocker is continued for 1 to 3 years.
Hence, maintenance oral therapy of 50 mg daily of atenolol 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.

With impaired renal function.

Since atenolol is excreted via the kidneys, dosage should be adjusted in cases of severe impairment of renal function. No significant accumulation of atenolol occurs at a creatinine clearance greater than 35 mL/min/1.73 m2 (normal range is 100 to 150 mL/min/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, or 100 mg on alternate days.
For patients with a creatinine clearance of less than 15 mL/min/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.

Elderly.

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

Children.

There is no experience with atenolol in children.

Overdosage

For information on the management of overdose, contact the Poisons Information Centre on 131 126 (Australia).
Overdosage has not been reported with atenolol, but in overdosage with other beta-blocking agents, severe bradycardia and hypotension are commonly found. Acute heart failure and bronchospasm may also occur.

Management.

Severe bradycardia.

Atropine, 1 to 2 mg intravenously, may be used to induce vagal blockade. If bradycardia persists an inotrope, such as intravenous isoprenaline (25 microgram initially) may be given. In refractory cases, the use of a cardiac pacemaker may be considered.

Hypotension.

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

Bronchospasm.

Therapy with a beta2-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.

Presentation

Tablets (white to off white, circular, biconvex, film coated), 25 mg* (marked 25 on one side, plain on reverse); 50 mg (marked 50 on one side, scored on reverse); 100 mg* (marked 100 on one side, scored on reverse): 10's*, 14's*, 28's*, 30's, 50's*, 56's*, 60's*, 84's*, 98's*, 112's*, 120's* (PVC/ PVDC/ Al blister pack) or 100's, 250's, 500's (HDPE bottles*).
*Not currently marketed in Australia.

Storage

Protect from light and moisture. Store below 25°C.

Poison Schedule

S4.