METROL

What it is

METROL is metoprolol tartrate 50 mg and 100 mg film coated tablets. Metoprolol is a relatively cardioselective beta-blocker that acts on beta₁-receptors mainly located in the heart at lower doses than those needed to influence the beta₂-receptors mainly located in the bronchi and peripheral vessels.

Approved indications

— Hypertension, as monotherapy or for use in combination with other antihypertensives. — Angina pectoris, for long-term prophylaxis. — Confirmed or suspected myocardial infarction. — Prevention of migraine.

Dosing overview

The maximum daily dose should not exceed 400 mg. Although twice daily dosage is optimal, in those patients whose maintenance dosage is 150 mg daily or less, it may be administered as a single dose.

Key safety warnings

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 a tendency to bronchospasm. 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. In patients without a history of cardiac failure, continuing depression of the myocardium may lead to cardiac failure. There is a risk of exacerbating the number and duration of coronary artery spasms if patients with Prinzmetal angina or variant angina pectoris are treated with a beta-blocker, including METROL. If this treatment is essential, it should only be undertaken in a Coronary or Intensive Care Unit. METROL should be used with caution in patients with diabetes mellitus, especially those who are receiving insulin or oral hypoglycaemic agents. Diabetic patients should be warned that beta-blockers, including METROL, affect glucose metabolism and may mask some important premonitory signs of acute hypoglycaemia, such as tachycardia. 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 8–14 days, during which time the patient's progress should be assessed.

Contraindications

METROL is contraindicated in known hypersensitivity to metoprolol and related derivatives, hypersensitivity to any of the excipients, sensitivity to other beta-blockers, atrioventricular block of second or third degree, congestive heart failure, sinus bradycardia (less than 45 to 50 beats/minute), sick-sinus syndrome, severe peripheral arterial circulatory disorders, shock (including cardiogenic and hypovolaemic shock), myocardial infarction patients with a heart rate of less than 45 beats/min, a P-R interval of greater than 0.24 sec, a systolic blood pressure of less than 100 mm Hg, and/or moderate to severe heart failure, right ventricular failure secondary to pulmonary hypertension, significant right ventricular hypertrophy, hypotension, untreated phaeochromocytoma, and allergic disorders (including allergic rhinitis) which may suggest a predisposition to bronchospasm. METROL is contraindicated in severe bronchial asthma or history of severe bronchospasm.

Regulatory history

METROL was first included in the ARTG on 25 March 2015. The 50 mg and 100 mg tablet formulations were first listed in the ARTG on 23 September 2015.