BETAZOK Metoprolol Succinate 25mg Controlled-Release Tablet 1's
Indications/Uses
Dosage/Direction for Use
Hypertension: The recommended dosage in patients with hypertension is 100-200 mg daily, given as a single dose in the morning or in divided doses (morning and evening). If needed, other antihypertensive agents may be added.
Long-term antihypertensive treatment with metoprolol in daily doses of 100-200 mg has been shown to reduce total mortality, including sudden cardiovascular death, stroke and coronary events in hypertensive patients.
Angina pectoris: The recommended dosage is 100-200 mg daily, given in divided doses (morning and evening). If needed, other antianginal agents may be added.
Cardiac arrhythmias: The recommended dosage is 100-200 mg daily given in divided doses (morning and evening). If needed, other antiarrhythmic agents may be added.
Maintenance treatment after myocardial infarction: Long-term oral treatment with metoprolol in doses of 200 mg daily, given in divided doses (morning and evening) has been shown to reduce the risk of death (including sudden death), and to reduce the risk of reinfarction (also in patients with diabetes mellitus).
Functional heart disorders with palpitations: The recommended dosage is 100 mg once daily, given as a single dose in the morning. If needed, the dose can be increased to 200 mg.
Migraine prophylaxis: The recommended dosage is 100-200 mg daily, given in divided doses morning and evening.
Hyperthyroidism: The recommended dosage is 150-200 mg daily, divided in 3-4 doses. If needed, the dose can be increased.
Impaired renal function: Dose adjustment is not needed in patients with impaired renal function.
Impaired hepatic function: Dose adjustment is normally not needed in patients suffering from liver cirrhosis because metoprolol has a low protein binding (5-10 %). When there are signs of serious impairment of liver function (e.g. shunt-operated patients) a dose reduction should be considered.
Elderly: Dose adjustment is not needed in the elderly.
Children: There is limited experience with metoprolol treatment in children.
Overdosage
Management: Care should be provided at a facility that can provide appropriate supporting measures, monitoring, and supervision.
If justified, gastric lavage and/or activated charcoal can be administered.
Atropine, adreno stimulating drugs or pacemaker to treat bradycardia and conduction disorders.
Hypotension, acute cardiac failure, and shock to be treated with suitable volume expansion, injection of glucagon (if necessary, followed by an intravenous infusion of glucagon), intravenous administration of adrenostimulating drugs such as dobutamine, with α1 receptor agonistic drugs added in presence of vasodilation. Intravenous use of Ca2+ can also be considered.
Bronchospasm can usually be reversed by bronchodilators.
Administration
Contraindications
Metoprolol should not be given to patients with suspected acute myocardial infarction as long as the heart rate is <45 beats/min, the P-Q interval is > 0.24 sec or the systolic blood pressure is <100 mm Hg.
Metoprolol tartrate tablets are contraindicated in patients who have shown hypersensitivity to any component of the products or to other β-blockers
Special Precautions
Generally when treating patients with asthma, concomitant therapy with a β2-agonist (tablet and/or inhalation) should be administered. The dosage of β2-agonists may require adjustment (increase) when treatment with metoprolol is started.
During treatment with metoprolol, the risk of interfering with carbohydrate metabolism or masking hypoglycaemia is less than with non-selective β-blockers. Patients suffering from heart failure should have their decompensation treated both before and during treatment with metoprolol.
Very rarely, a pre-existing A-V conduction disorder of moderate degree may become aggravated (possibly leading to A-V block).
If the patients develop increasing bradycardia, metoprolol should be given in lower doses or gradually withdrawn.
Metoprolol may aggravate the symptoms of peripheral arterial circulatory disorders.
Where metoprolol is prescribed for a patient known to be suffering from a pheochromocytoma, an alpha-blocker should be given concomitantly.
Abrupt interruption of the medication is to be avoided. If treatment has to be withdrawn it should, when possible, be done gradually. Many patients can be withdrawn over a 14 day period.
This can be done by cutting the daily dose in sequential steps reaching a final dose of 25 mg once a day (half a 50 mg tablet).
During this period especially patients with known ischemic heart disease should be kept under close surveillance. The risk for coronary events, including sudden death, may increase during the withdrawal of β-blockade.
Prior to surgery the anaesthetist should be informed that the patient is receiving metoprolol. It is not recommended to stop β-blocker treatment in patients undergoing surgery. Acute initiation of high-dose metoprolol to patients undergoing non-cardiac surgery should be avoided, since it has been associated with bradycardia, hypotension and stroke including fatal outcome in patients with cardiovascular risk factors.
In patients taking β-blockers anaphylactic shock assumes a more severe form.
Effects on ability to drive and use machines: Patients should know how they react to metoprolol before they drive or use machines because occasionally dizziness or fatigue may occur.
Use In Pregnancy & Lactation
The amount of metoprolol ingested via breast milk, however, seems to be negligible as regards β-blocking effect in the infant if the mother is treated with metoprolol in doses within the normal therapeutic range.
Adverse Reactions
The following definitions of frequencies are used: Very common (≥10%), common (1-9.9%), uncommon (0.1-0.9%), rare (0.01-0.09%) and very rare (<0.01%).
Cardiovascular system: Common: Bradycardia, postural disorders (very rarely with syncope), cold hands and feet, palpitations. Uncommon: Deterioration of heart failure symptoms, cardiogenic shock in patients with acute myocardial infarction*, first degree heart block, oedema, precordial pain. Rare: Disturbances of cardiac conduction, cardiac arrhythmias. Very rare: Gangrene in patients with pre-existing severe peripheral circulatory disorders.
*Excess frequency of 0.4% compared with placebo in a study of 46,000 patients with acute myocardial infarction where the frequency of cardiogenic shock was 2.3% in the metoprolol group and 1.9% in the placebo group in the subset of patients with low shock risk index. The shock risk index was based on the absolute risk of shock in each individual patient derived from age, sex, time delay, Killip class, blood pressure, heart rate, ECG abnormality, and prior history of hypertension. The patient group with low shock risk index corresponds to the patients in which metoprolol is recommended for use in acute myocardial infarction.
Central nervous system: Very common: Fatigue. Common: Dizziness, headache. Uncommon: Paraesthesiae, muscle cramps.
Gastrointestinal: Common: Nausea, abdominal pain, diarrhoea, constipation. Uncommon: Vomiting. Rare: Dry mouth.
Haematologic: Very rare: Thrombocytopenia.
Hepatic: Rare: Liver function test abnormalities. Very rare: Hepatitis.
Metabolism: Uncommon: Weight gain.
Musculoskeletal: Very rare: Arthralgia.
Psychiatric: Uncommon: Depression, concentration impaired, somnolence or insomnia, nightmares. Rare: Nervousness, anxiety, impotence/sexual dysfunction. Very rare: Amnesia/memory impairment, confusion, hallucinations.
Respiratory: Common: Dyspnoea on exertion. Uncommon: Bronchospasm. Rare: Rhinitis.
Sense organs: Rare: Disturbances of vision, dry and/or irritated eyes, conjunctivitis. Very rare: Tinnitus, taste disturbances.
Skin: Uncommon: Rash (in the form of urticaria psoriasiform and dystrophic skin lesions), increased sweating. Rare: Loss of hair. Very rare: Photosensitivity reactions, aggravated psoriasis.
Drug Interactions
Patients receiving concomitant treatment with sympathetic ganglion blocking agents, other β-blockers (i.e. eye drops), or Mono Amine Oxidase (MAO) inhibitors should be kept under close surveillance.
If concomitant treatment with clonidine is to be discontinued, the β-blocker medication should be withdrawn several days before clonidine.
Increased negative inotropic and chronotropic effects may occur when metoprolol is given together with calcium antagonists of the verapamil and diltiazem type. In patients treated with β-blockers intravenous administration of calcium antagonists of the verapamil-type should not be given.
β-blockers may enhance the negative inotropic and negative dromotropic effect of antiarrhythmic agents (of the quinidine type and amiodarone).
Digitalis glycosides, in association with β-blockers, may increase atrioventricular conduction time and may induce bradycardia.
In patients receiving β-blocker therapy, inhalation anaesthetics enhance the cardiodepressant effect.
Concomitant treatment with indomethacin or other prostaglandin synthetase inhibiting drugs may decrease the antihypertensive effect of β-blockers.
Under certain conditions, when adrenaline is administered to patients treated with β-blockers, cardioselective β-blockers interfere much less with blood pressure control than non-selective β-blockers.
The dosages of oral antidiabetics may have to be readjusted in patients receiving β-blockers.
Caution For Usage
Instructions for use, handling and disposal: Not applicable.
Storage
Action
Pharmacology: Pharmacodynamics: Metoprolol is a β1-selective β-blocker, i.e. it blocks β1-receptors at doses much lower than those needed to block β2-receptors.
Metoprolol has an insignificant membrane-stabilising effect and does not display partial agonistic activity.
Metoprolol reduces or inhibits the agonistic effect on the heart of catecholamines (which are released during physical and mental stress). This means that the usual increase in heart rate, cardiac output, cardiac contractility and blood pressure, produced by the acute increase in catecholamines, is reduced by metoprolol. During high endogenous adrenaline levels metoprolol interferes much less with blood pressure control than non-selective β-blockers. When required, metoprolol, in combination with a β2-agonist, may be given to patients with symptoms of obstructive pulmonary disease. When given together with a β2-agonist, metoprolol in therapeutic doses interferes less than non-selective β-blockers with the β2-mediated bronchodilation caused by the β2-agonist.
Metoprolol interferes less with insulin release and carbohydrate metabolism than do non-selective β-blockers.
Metoprolol interferes much less with the cardiovascular response to hypoglycaemia than do non-selective β-blockers.
Short term studies have shown that metoprolol may cause a slight increase in triglycerides and a decrease in free fatty acids in the blood. In some cases, a small decrease in the high density lipoproteins (HDL) fraction has been observed, although to a lesser extent than that following non-selective β-blockers. However, a significant reduction in total serum cholesterol levels has been demonstrated after metoprolol treatment in one study conducted over several years.
Quality of Life is maintained uncompromised or improved during treatment with metoprolol.
An improvement in Quality of Life has been observed after metoprolol treatment in patients after myocardial infarction.
Effect in hypertension: Metoprolol lowers elevated blood pressure both in the standing and lying position. A short-lasting (a few hours) and clinically insignificant increase in peripheral resistance may be observed after the institution of metoprolol treatment. During long-term treatment total peripheral resistance may be reduced, due to reversal of hypertrophy in arterial resistance vessels. Long-term antihypertensive therapy with metoprolol has also been shown to reduce left ventricular hypertrophy and to improve left ventricular diastolic function and left ventricular filling.
In men with mild to moderate hypertension metoprolol has been shown to reduce the risk of death from cardiovascular disease mainly due to a reduced risk for sudden cardiovascular death, to reduce the risk of fatal and non-fatal myocardial infarction and for stroke.
Effect on angina pectoris: In patients with angina pectoris metoprolol has been shown to reduce the frequency, duration and severity of both angina attacks and silent ischemic episodes and to increase the physical working capacity.
Effect on cardiac rhythm: In cases of supraventricular tachycardia or atrial fibrillation, and in the presence of ventricular extrasystoles, metoprolol slows the ventricular rate and reduces ventricular extrasystoles.
Effect on myocardial infarction: In patients with suspected or confirmed myocardial infarction metoprolol lowers mortality mainly due to a reduction in the risk of sudden death. This effect is presumed to partly be due to the prevention of ventricular fibrillation.
MedsGo Class
Features
- Metoprolol