ATENOLOL 50 mg TABLETS

1. The management of hypertension

2. The management of angina pectoris

3. The management of cardiac arrhythmias

4. Myocardial infarction: Early intervention in the acute phase and long-term prophylaxis after recovery from myocardial infarction.

Posology

The dose must always be adjusted to individual requirements of the patients, with the lowest possible starting dosage. The following are the guidelines:

Adults

Hypertension:

One tablet daily. Most patients respond to 100mg daily given orally as a single dose. Some patients, however, will respond to 50mg given as a single daily dose. The effect will be fully established after one to two weeks. A further reduction in blood pressure may be achieved by combining Atenolol with other antihypertensive agents. For example, co-administration of Atenolol with a diuretic, as in tenoretic provides a highly effective and convenient antihypertensive therapy.

Angina:

Most patients with angina pectoris will respond to 100mg given orally once daily or 50mg given twice daily. It is unlikely that additional benefit will be gained by increasing the dose.

Cardiac arrhythmias

A suitable initial dose of atenolol tablets is 2.5 mg (5 ml) injected intravenously over a 2.5minute period (i.e. 1 mg/minute). (See also prescribing information for atenolol Injection.) This may be repeated at 5minute intervals, until a response is observed up to a maximum dosage of 10 mg. If atenolol is given by infusion, 0.15 mg/kg bodyweight may be administered over a 20minute period. If required, the injection or infusion may be repeated every 12 hours. Having controlled the arrhythmias with intravenous atenolol a suitable maintenance dosage is 50mg - 100mg daily, given as a single dose.

Myocardial infarction:

For patients suitable for treatment with intravenous beta-blockade and presenting within 12 hours of the onset of chest pain, atenolol 5– 10 mg should be given by slow intravenous injection (1 mg/minute) followed by atenolol 50 mg orally about 15 minutes later, provided that no untoward effects have occurred from the intravenous dose. This should be followed by a further 50mg orally 12 hours after the intravenous dose and then 12 hours later by 100mg to be given once daily for up to ten days. If bradycardia and/or hypotension requiring treatment, or any other untoward effects occur, Atenolol should be discontinued.

Renal failure:

Atenolol is excreted via the kidneys, the dosage adjustment should be considered in patients with severe impairment of renal function.

No significant accumulation of atenolol occurs in patients who have a creatinine clearance greater than 35 ml/min/1.73 m² (normal range is 100–150 ml/min/1.73 m²).

For patients with a creatinine clearance of 15–35 ml/min/1.73 m² (equivalent to serum creatinine of 300- 600micromol/litre), the oral dose should be 50mg daily and the intravenous dose should be 10 mg once every two 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/litre), the oral dose should be 25 mg daily or 50 mg on alternate days and the intravenous dose should be 10 mg once every four days.

Patients on haemodialysis should be given 50mg atenolol orally after each dialysis. Because of the possibility of marked falls in blood pressure, this should be carried out under hospital supervision.

Elderly

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

Paediatric population

There is no paediatric experience with atenolol and for this reason it is not recommended for use in children.

Method of administration

For oral administration.

Atenolol tablets, as with other beta-blockers, should not be used in patients with any of the following:

• hypersensitivity to the active substance or to any of the excipients listed in section 6.1.

• second-degree or third-degree heart block.

• bradycardia (<45 bpm).

• Uncontrolled heart failure.

• cardiogenic shock.

• sick sinus syndrome.

• untreated phaeochromocytoma.

• severe peripheral arterial circulatory disturbances.

• metabolic acidosis.

• hypotension.

Atenolol with other beta-blockers:

Sudden withdrawal of Beta-adrenoceptor blocking agents in patients with ischaemic heart disease may result in the appearance of angina attacks of increased frequency or severity or deterioration in cardiac state. Atenolol therapy must not be withdrawn abruptly. The dosage should be reduced gradually over a period of 7–14 days, to facilitate a reduction in beta blockers dosage and patients should be monitored during withdrawal, especially those with ischaemic heart disease.

Anaesthesia:

If a beta-blocker is withdrawn prior to surgery it should be discontinued for at least 24 hours. The risk-benefit assessment of stopping beta-blockade should be made for each patient. If treatment is continued, an anaesthetic with little negative inotropic activity should be selected to minimize the risk of myocardial depression. The patient may be protected against vagal reactions by intravenous administration of atropine.

Although contraindicated in uncontrolled heart failure (see section 4.3), atenolol may be used in patients whose signs of heart failure have been controlled. Caution must be exercised in patients whose cardiac reserve is poor.

Beta-blockers may increase both the sensitivity towards allergens and the seriousness to patients with a history of anaphylactic reactions. Such patients may be unresponsive to the usual doses of adrenaline (epinephrine) used to treat the allergic reactions.

Atenolol may increase the number and duration of angina attacks in patients with Prinzmetal's angina due to unopposed alpha receptor mediated coronary artery vasoconstriction. Atenolol is a beta1 selective beta adrenoceptor blocking drug; consequently its use may be considered although utmost caution must be exercised.

Although contraindicated in severe peripheral arterial circulatory disturbances, (see section 4.3) atenolol may also aggravate less severe peripheral arterial circulatory disturbances.

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

May mask the symptoms of hypoglycaemia, in particular tachycardia

The signs of thyrotoxicosis may be masked by atenolol treatment.

May cause a hypersensitivity reaction including angioedema and urticaria.

Will reduce heart rate as a result of its pharmacological action. In the rare instances where a treated patient develops symptoms which may be attributable to a slow heart rate and the pulse drops to less than 50-55 bpm at rest, the dose should be reduced.

Should be used with caution in the elderly, starting with a lower dose (see section 4.2).

Since atenolol is excreted via the kidneys, the dosage should be reduced in patients with a creatinine clearance of less than 35ml/minute/1.73m².

Although cardioselective (beta1) beta-blockers may have less effect on lung function than non-selective beta-blockers, as with all beta-blockers, these should be avoided in patients with reversible obstructive airways disease, unless there are compelling clinical reasons for their use. Where such reasons exist, atenolol may be used with caution. Occasionally, some increase in airways resistance may occur in asthmatic patients however, and this may usually be reversed by commonly used dosage of bronchodilators such as salbutamol or isoprenaline. The label and patient information leaflet for this product state the following warning: “If you have ever had asthma or wheezing, you should not take this medicine unless you have discussed these symptoms with the prescribing doctor” .

As with other beta-blockers, in patients with a phaeochromocytoma, an alpha-blocker should be given concomitantly.

Anaesthetics, General:

Caution should be exercised when using anaesthetic agents with atenolol. The anaesthetist should be informed and the choice of anaesthetic should be an agent with as little negative inotropic activity as possible. Use of beta-blockers with anaesthetic drugs may result in attenuation of the reflex tachycardia and increase the risk of hypotension. Anaesthetic agents causing myocardial depression are best avoided (see section 4.4).

Anti-arrhythmics:

Class I anti-arrhythmic drugs (e.g. disopyramide) and amiodarone may have a potentiating effect on atrial-conduction time and induce negative inotropic effect.

Antidiabetics:

Concomitant use with insulin and oral antidiabetic drugs may lead to the intensification of the blood sugar lowering effects of these drugs. . Symptoms of hypoglycaemia, particularly tachycardia, may be masked (see sections 4.4).

Calcium-channel blockers:

Combined use of beta-blockers and calcium channel blockers with negative inotropic effects, e.g. verapamil and diltiazem, can lead to an exaggeration of these effects particularly in patients with impaired ventricular function and/or sinoatrial or atrioventricular conduction abnormalities. This may result in severe hypotension, bradycardia and cardiac failure. Neither the beta-blocker nor the calcium channel blocker should be administered intravenously within 48 hours of discontinuing the other.

Concomitant therapy with dihydropyridines, e.g. nifedipine, may increase the risk of hypotension, and cardiac failure may occur in patients with latent cardiac insufficiency.

Clonidine:

Beta-blockers may exacerbate the rebound hypertension which can follow the withdrawal of clonidine. If the two drugs are co-administered, the beta-blocker should be withdrawn several days before discontinuing clonidine. If replacing clonidine by beta-blocker therapy, the introduction of beta-blockers should be delayed for several days after clonidine administration has stopped. (See also prescribing information for clonidine.).

Digoxin:

Digitalis glycosides, in association with beta-blockers, may increase atrioventricular conduction time.

NSAIDs:

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

Sympathomimetics:

Concomitant use of sympathomimetic agents, e.g. adrenaline (epinephrine), may counteract the effect of beta-blockers.

Caution should be exercised when atenolol is administered during pregnancy or to a woman who is breast-feeding.

Pregnancy:

Atenolol crosses the placental barrier and appears in the cord blood. 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 to pregnant women in the management of mild to moderate hypertension has been associated with intra-uterine 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, since beta-blockers, in general, have been associated with a decrease in placental perfusion which may result in growth retardation, intra-uterine deaths, abortion, immature and premature deliveries.

Breast-feeding:

There is significant accumulation of atenolol in breast milk.

Neonates born to mothers who are receiving atenolol at parturition or breast- feeding may be at risk of hypoglycaemia and bradycardia.

Atenolol has no or negligible influence on the ability to drive and use machines. However, it should be taken into account that occasionally dizziness or fatigue may occur.

Atenolol is well-tolerated. In clinical studies, the undesired events reported are usually attributable to the pharmacological actions of atenolol.

The following undesired events, listed by body system, have been reported with the following frequencies: very common (≥ 1/10); common (≥ 1/100 to < 1/10); uncommon (≥ 1/1,000 to < 1/100); rare (≥ 1/10,000 to < 1/1,000); very rare (< 1/10,000); including isolated reports not known (cannot be estimated from the available data).

Discontinuation of atenolol should be considered if, according to clinical judgment, the well-being of the patient is adversely affected by any of the above reactions. Cessation of therapy with a beta-blocker should be gradual.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation 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 via the Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

The symptoms of overdosage may include bradycardia, hypotension, acute cardiac insufficiency and bronchospasm.

Management:

Close supervision; treatment in an intensive care ward; the use of gastric lavage; activated charcoal and a laxative to prevent absorption of any drug still present in the gastrointestinal tract; and the use of plasma or plasma substitutes to treat hypotension and shock. The uses of haemodialysis or haemoperfusion may be considered.

Excessive bradycardia can be countered with atropine 1–2 mg intravenously and/or a cardiac pacemaker. If necessary, this may be followed by a bolus dose of glucagon 10 mg intravenously. If required, this may be repeated or followed by an intravenous infusion of glucagon 1–10 mg/hour depending on response. If no response to glucagon occurs or if glucagon is unavailable, a beta- adrenoceptor stimulant such as dobutamine 2.5 to 10 micrograms/kg/minute by intravenous infusion may be given. Dobutamine, because of its positive inotropic effect could also be used to treat hypotension and acute cardiac insufficiency.

It is likely that these doses would be inadequate to reverse the cardiac effects of beta-blocker blockade if a large overdose has been taken. The dose of dobutamine should therefore be increased if necessary to achieve the required response according to the clinical condition of the patient.

Bronchospasm can usually be reversed by bronchodilators.

Pharmacotherapeutic group: Beta blocking agents, plain selective, ATC code: C07A B03.

Mechanism of action

Atenolol is a beta-blocker which is beta1-selective, (i.e. acts preferentially on beta1-adrenergic receptors in the heart). Selectivity decreases with increasing dose.

Atenolol is without intrinsic sympathomimetic and membrane-stabilising activities and as with other beta-blockers, has negative inotropic effects (and is therefore contraindicated in uncontrolled heart failure).

As with other beta-blockers, the mode of action of atenolol in the treatment of hypertension is unclear.

It is probably the action of atenolol in reducing cardiac rate and contractility which makes it effective in eliminating or reducing the symptoms of patients with angina.

It is unlikely that any additional ancillary properties possessed by S (-) atenolol, in comparison with the racemic mixture, will give rise to different therapeutic effects

Clinical efficacy and safety

Atenolol is effective and well tolerated in most ethnic populations although the response may be less in black patients.

Atenolol is effective for at least 24 hours after a single oral dose. The drug facilitates compliance by its acceptability to patients and simplicity of dosing. The narrow dose range and early patient response ensure that the effect of the drug in individual patients is quickly demonstrated. Atenolol is compatible with diuretics, other hypotensive agents and antianginals (see section 4.5). Since it acts preferentially on beta-receptors in the heart, Atenolol may, with care, be used successfully in the treatment of patients with respiratory disease, who cannot tolerate non-selective betablockers.

Early intervention with Atenolol in acute myocardial infarction reduces infarct size and decreases morbidity and mortality. Fewer patients with a threatened infarction progress to frank infarction; the incidence of ventricular arrhythmias is decreased and marked pain relief may result in reduced need of opiate analgesics. Early mortality is decreased. Atenolol is an additional treatment to standard coronary care.

Absorption

Absorption of atenolol following oral dosing is consistent but incomplete (approximately 40–50%) with peak plasma concentrations occurring 2–4 hours after dosing. The atenolol blood levels are consistent and subject to little variability. There is no significant hepatic metabolism of atenolol and more than 90% of that absorbed reaches the systemic circulation unaltered.

Distribution

Atenolol penetrates tissues poorly due to its low lipid solubility and its concentration in brain tissue is low. Plasma protein binding is low (approximately 3%).

Elimination

The plasma half-life is about 6 hours but this may rise in severe renal impairment since the kidney is the major route of elimination.

Atenolol is a drug on which extensive clinical experience has been obtained. Relevant information for the prescriber is provided elsewhere in the prescribing information.

Gelatin

Heavy Magnesium Carbonate

Magnesium Stearate

Microcrystalline Cellulose

Maize Starch

Sodium Lauryl Sulphate

Talc

Purified Water

Not applicable

5 years.

Do not store above 25ºC.

Keep the container tightly closed (bottles and tablet containers). Store in the original package (blisters).

a) Amber glass bottles with closures of LD-polyethylene.

b) Polypropylene tablet container with polyethylene cap.

c) Blister strips made of clear PVC plastic foil 250micrometer thick and aluminium foil, hard-tempered, 20micrometer thick, laminated against 30g PVC.

Pack sizes 28, 100, 250 tablets.

Not all pack sizes may be marketed

No special requirements.