|
|||
|
DRUGS & SUPPLEMENTS
|
Metoprolol
What do you feel about the cost of the medicine? Is it expensive? |
Metoprolol uses
Pharmacological action
Metoprolol is a cardioselective beta1-blocker without intrinsic sympathomimetic activity. This medication has antihypertensive, antianginal and antiarrhythmic effect. Metoprolol decreases automaticity of sinus node, reducing heart rate, slows AV-conduction, decreases myocardial contractility and excitability, reduces cardiac output, reduces myocardial oxygen demand. This drug inhibits the stimulatory effect of catecholamines on the heart during physical and psycho-emotional stress.
Metoprolol causes a hypotensive effect which is stabilized by the end of the second week of a course. With angina Metoprolol reduces the frequency and severity of attacks.
This medicine also normalizes the heart rate during supraventricular tachycardia and atrial fibrillation; when myocardial infarction it contributes to limit the zone of ischemia of the heart muscle and reduces the risk of developing fatal arrhythmias, reduces the risk of recurrence of myocardial infarction. When Metoprolol is used in the medium therapeutic doses it has a less pronounced effect on smooth muscles of the bronchi and peripheral arteries than non-selective beta-blockers.
Pharmacokinetics
After oral administration Metoprolol is rapidly and almost completely absorbed from the gastrointestinal tract, Cmax of the active substance in the blood plasma is reached after 1-2 hours. This medication intensively metabolized in the liver to form inactive metabolites. T1/2 of Metoprolol from plasma is 3-4 h and during the course of treatment it does not change. More than 95% of the dose excreted by the kidneys of which only 3% is in unchanged form.
Why is Metoprolol prescribed?
Hypertension, prevention of angina, cardiac arrhythmias, secondary prevention after myocardial infarction, cardiac hyperkinetic syndrome (including in hyperthyroidism, NDCs). Prophylaxis of migraine.
Dosage and administration
For oral administration the average dose of Metoprolol is 100 mg / day in 1-2 reception. If necessary the daily dose gradually increased up to 200 mg. For IV injections a single dose is 2.5 mg, with no effect a re-introduction is possible in 5 minutes.
Maximum daily dose for oral administration is 400 mg, for IV injections a single dose is 15-20 mg.
Metoprolol side effects, adverse reactions
Cardiovascular system: possible bradycardia, hypotension, AV-conduction disturbances, symptoms of heart failure.
Digestive system: at the beginning of therapy may include dry mouth, nausea, vomiting, diarrhea, constipation, and in some cases - liver function abnormalities.
CNS and peripheral nervous system: at the beginning of therapy may be weakness, fatigue, dizziness, headache, muscle cramps, coldness and paresthesia in the extremities; possible reduction in the secretion of tear fluid, conjunctivitis, rhinitis, depression, sleep disturbances, nightmares.
Hemopoietic system: in some cases - thrombocytopenia.
Endocrine: hypoglycemic state in patients with diabetes.
Respiratory system: in predisposed patients may cause symptoms of bronchial obstruction.
Allergic reactions: skin rash, itching.
Metoprolol contraindications
AV-block II and III degree, sinoatrial block, bradycardia, SSS, hypotension, chronic heart failure IIB-III stages, acute heart failure, cardiogenic shock, metabolic acidosis, pronounced disturbances of peripheral circulation, increased sensitivity to Metoprolol.
Using during pregnancy and breastfeeding
Taking of Metoprolol during pregnancy is only possible if the intended benefits to the mother outweighs the potential risk to the fetus. This medication crosses the placental barrier. In connection with the possible development of a newborn bradycardia, hypotension, hypoglycemia, and respiratory failure, Metoprolol should be abolished for 48-72 hours before the scheduled date of delivery. After delivery it is necessary to ensure strict monitoring of the newborn within 48-72 hours.
Metoprolol in small amounts excreted in breast milk. The using during lactation is not recommended.
Special instructions
With careful use in patients with chronic obstructive airways disease, diabetes, Raynaud's disease and obliterative peripheral arterial disease, pheochromocytoma (to be used in combination with alpha-blockers), pronounced renal and liver functions impairment.
During treatment with Metoprolol a production of lacrimal fluid may decreases, which is important for patients who use contact lenses.
Completion of a long course of treatment with Metoprolol should be gradual (at least 10 days) under the supervision of a physician.
There is not recommended for concurrent use of Metoprolol with MAO inhibitors.
Combined therapy with clonidine should receive the later stop in a few days after discontinuation of Metoprolol, in order to avoid a hypertensive crisis. Simultaneous administration of Metoprolol with hypoglycemic agents require correction of their dosing regimen.
A few days before the anesthesia it is necessary to stop taking this drug or find any anesthesia medication with minimal negative inotropic effects.
Patients whose work requires more attention, the application of Metoprolol outpatients should be addressed only after the evaluation of individual patient response.
Metoprolol drug interactions
Sympatholytics, nifedipine, nitroglycerin, diuretics, hydralazine and other antihypertensive drugs potentiate hypotension.
Antiarrhythmic and anesthetic medications increase the risk of bradycardia, arrhythmia, hypotension.
Digitalis drugs potentiate slowing AV conduction.
Simultaneously intravenous injection of verapamil and diltiazem may cause cardiac arrest.
Beta-adrenoceptor agonists, aminophylline, cocaine, estrogens, indomethacin and other NSAIDs impair antihypertensive effect.
Metoprolol enhances and prolongs the action of anti depolarizing muscle relaxants.
Combination with alcohol leads to mutual reinforcement of inhibitory effects on the CNS.
Allergens increased the risk of severe systemic allergic reactions or anaphylaxis.
Metoprolol edits the effectiveness of insulin and oral antidiabetic drugs and increases the risk of hypoglycemia.
Oral contraceptives, cimetidine, ranitidine, phenothiazines raise the level of this drug in the blood, rifampicin decreases it.
Metoprolol reduces the clearance of lidocaine, the effectiveness of beta 2-agonists (it is necessary to increase the dose of the latter).
This medicine is incompatible with MAO inhibitors of type A.
Metoprolol in case of emergency / overdose
Symptoms: hypotension, acute heart failure, bradycardia, heart block, AV block, cardiogenic shock, bronchospasm, trouble breathing and consciousness, coma, nausea, vomiting, generalized convulsions, cyanosis (manifest in 20 minutes - 2 hours after taking of Metoprolol).
Treatment: gastric lavage, the symptomatic therapy: atropine sulfate injection (IV fast 0.5-2 mg) if bradycardia and a violation of AV conduction; glucagon (1-10 mg IV, then IV infusion 2-2.5 mg / h) and dobutamine in the case of reduction of myocardial contractility; agonists (noradrenaline, adrenaline, etc.) when arterial hypotension; diazepam (IV slowly) to eliminate seizures; beta-agonists inhalation or IV jet injection of aminophylline to relieve broncho spastic reactions; cardioacceleration.
Metoprolol pharmaceutical active ingredients containing related brand and generic drugs:
Metoprolol available forms, composition, doses:
Composition is the list of ingredients which combinedly form a medicine. Both active ingredients and inactive ingredients form the composition. The active ingredient gives the desired therapeutic effect whereas the inactive ingredient helps in making the medicine stable.
Doses are various strengths of the medicine like 10mg, 20mg, 30mg and so on. Each medicine comes in various doses which is decided by the manufacturer, that is, pharmaceutical company. The dose is decided on the severity of the symptom or disease.