ATENOLOL

What it is

Atenolol Sandoz is a medicine containing 50 mg of atenolol per tablet. Atenolol is a beta-adrenoceptor blocking agent, which acts preferentially on beta-receptors in the heart. It has little intrinsic sympathomimetic activity and no membrane stabilising activity.

Approved indications Atenolol Sandoz is indicated in the management of:

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

Dosing overview

For hypertension, therapy should be initiated with Atenolol Sandoz 50 mg daily, which may be increased each week in daily doses of 50 mg up to a maximum of 200 mg. For angina pectoris, therapy should be initiated with 50 mg daily and may be increased, if required, to 100 mg daily given as a single or divided dose. For cardiac dysrhythmias, atenolol given orally at a dosage of 50 mg to 100 mg daily will help maintain control after dysrhythmias have been controlled with other intravenous agents. Following myocardial infarction, maintenance oral therapy of Atenolol Sandoz 50 mg daily is recommended for one to three years, beginning after early intervention with other agents, or immediately in those patients who present more than 12 hours after suffering an acute myocardial infarction. In patients with severe renal impairment, dosage should be adjusted; no significant accumulation occurs at a creatinine clearance greater than 35 mL/minute/1.73 m², but for patients with a creatinine clearance of 15 to 35 mL/minute/1.73 m², the oral dose should be 50 mg daily or 100 mg on alternate days, and for patients with a creatinine clearance of less than 15 mL/minute/1.73 m², the oral dose should be 50 mg on alternate days or 100 mg every fourth day.

Key safety warnings

Care should be taken if beta-blockers have to be discontinued abruptly in patients with coronary artery disease, as severe exacerbation of angina and precipitation of myocardial infarction and ventricular arrhythmias have occurred following abrupt discontinuation; it is recommended that the dosage be reduced gradually over a period of about 8 to 14 days. 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, and in patients without a history of cardiac failure, continuing depression of the myocardium may lead to cardiac failure. Patients with a history of anaphylactic reaction to a variety of allergens may have a more severe reaction on repeated challenge whilst taking beta-adrenoreceptor blocking drugs, and such patients may be unresponsive to the usual doses of adrenaline used to treat the allergic reactions. Beta-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, 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. Beta-blockade may impair the peripheral circulation and exacerbate the symptoms of peripheral vascular disease.

Contraindications

Beta-blockers are contraindicated in any patient with a history of airways obstruction or tendency to bronchospasm, as beta-adrenergic blockade of the smooth muscle of bronchi and bronchioles may result in an increased airways resistance. Additional contraindications include congestive heart failure, allergic disorders 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 hypovolaemic shock), anaesthesia with agents that produce myocardial depression, hypotension, metabolic acidosis, severe peripheral arterial circulatory disturbances, untreated phaeochromocytoma, and pregnancy and lactation. Known hypersensitivity to the active ingredient or any of the excipients is also a contraindication.

PBS listing

Atenolol Sandoz 50 mg tablets are listed on the PBS with 2 items under a restricted listing, at an ex-manufacturer price of A$2.50.

Regulatory history

Atenolol Sandoz 50 mg tablets (ARTG 101462) were first registered on 27 August 2004.