ATENOLOL

Posology Hypertension The usual dose is one 100 mg tablet daily. Some patients may respond to a dose of one 50 mg tablet daily. The therapeutic effect is fully established after administration for one to two weeks. Further reduction in blood pressure, if desired, can be achieved by combining atenolol with other antihypertensive agents.

Angina pectoris One 100 mg tablet once daily or one 50 mg tablet twice daily are taken. Additional benefit is unlikely to be gained by increasing the dose. Cardiac dysrhythmias Having controlled the dysrhythmia with intravenous atenolol the maintenance oral dose is one 50mg tablet to one 100 mg tablet daily as a single dose.

Myocardial infarction Patients presenting within 12 hours of the onset of chest pains and suitable for beta blockade therapy: 5 to 10 mg of atenolol is administered by slow intravenous injection (1 mg/minute). If no adverse effects occur following the intravenous dose, then 15 minutes later one 50 mg tablet is administered orally followed by a further 50 mg tablet, 12 hours after the intravenous dose.

Then 12 hours later one 100 mg tablet is given orally, once daily. If bradycardia and/or hypertension requiring treatment, or any other side effects, occur atenolol therapy should be discontinued. Elderly patients Dosage requirements may be reduced, especially in those with impaired renal function.

Paediatric population Atenolol is not recommended for use in children as there is no paediatric experience with atenolol. Renal impairment Since atenolol is excreted via the kidneys dosage should be adjusted in cases of severe impairment of renal function.

73m2). 73m2 (equivalent to serum creatinine of 300-600 μmol/litre) the oral dose should be one 50 mg tablet daily or one 100 mg tablet once every two days; the intravenous dose should be 10 mg once every two days. 73m2 (equivalent to serum creatinine of <600 μmol/litre) the oral dose should be one 50 mg tablet on alternate days or one 100 mg tablet once every four days; the intravenous dose should be 10 mg once every four days.

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. Method of administration For administration by the oral route

Atenolol tablets are well tolerated and the adverse effects experienced are usually a result of its pharmacological action, as with other beta-blockers. 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).

Cardiac disorders:

Common: Bradycardia.

Rare:

Heart failure, heart block.

Vascular disorders:

Common: Cold extremities.

Rare:

Hypotension, dizziness, syncope, intermittent claudication may be increased if already present, insusceptible patients Raynaud's phenomenon. Rarely, cases of peripheral gangrene have been reported with beta blockers.

Ear disorders:

Vertigo.

Eye disorders:

Rare: Visual disturbances including blurred vision, sore eyes, dry eyes (reversible on withdrawal; discontinuance of the drug should be considered if any such reaction is not otherwise explicable), conjunctivitis.

Gastrointestinal disorders:

Common: Nausea, vomiting, diarrhoea, constipation, abdominal cramps, sclerosing peritonitis and retroperitoneal fibrosis.

Blood and lymphatic system disorders:

• Care should be taken when using beta-blockers in patients with poor cardiac reserve. Myocardial contractility must be maintained and signs of failure controlled with digitalis and diuretics. 8). Treatment should not be discontinued abruptly in patients on long-term therapy, but should be discontinued over one to two weeks.

• If a beta-blocker is withdrawn prior to surgery it should be discontinued for at least 24 to 48 hours, if the patient is being anaesthetised. If beta blockers are not discontinued before anaesthesia, the anaesthetist should be made aware of the beta- blocker therapy.

A drug such as atropine may be given to counter increases in vagal tone. 5). • Atenolol reduces heart rate. In instances when symptoms may be attributable to the slow heart rate, the dose should be reduced. Beta-blockers should be used with caution in first degree AV block and portal hypertension (risk of deterioration in liver function).

• Beta-blockers may increase both the sensitivity towards allergens and seriousness of anaphylactic reactions. Patients with a history of anaphylaxis to an antigen may be more reactive to repeated challenge with the antigen while taking beta blockers.

Beta blockers may also reduce the response to adrenaline. They may unmask myasthenia gravis or potentiate a myasthenic condition. • Patients with psoriasis should only be given beta-blockers after careful consideration, as psoriasis may be aggravated.

• Atenolol should be used with caution in diabetics subject to frequent episodes of hypoglycaemia. The risk of hyperglycaemia is increased with concomitant use of a beta blocker and a thiazide. 5). " • If the use of atenolol in patients with asthma or a history of obstructive airways disease is unavoidable, the risk of inducing bronchospasm should be appreciated and administration of atenolol should be initiated with extreme caution and under specialist supervision.

1. • Severe bradycardia • Second degree or third degree heart block • Uncontrolled heart failure • Prinzmetal’s angina hypotension • Severe peripheral arterial circulatory disturbances (including intermittent claudication) • Sick sinus syndrome • Cardiogenic shock.

• Hypotension • Phaeochromocytoma (without a concomitant alpha blocker). • Metabolic acidosis. 4), unless there are compelling clinical reasons for their use.