Verapamil instructions for use
Verapamil is a calcium channel blocker. It is used in the treatment of cardiovascular diseases. Shows antianginal, antiarrhythmic and antihypertensive properties.
Release form and composition
Verapamil is available in film-coated tablets in doses of 40 mg and 80 mg. Tablets with the instruction are placed in a carton (10 and 50 tablets per pack). Another dosage form is a solution for intravenous administration.
The main active ingredient is verapamil hydrochloride.
Auxiliary components: calcium phosphate disubstituted, starch, magnesium stearate, hydroxypropylmethyl cellulose, butylhydroxyanisole, purified talc, gelatin, titanium dioxide, methylparaben, indigo carmine.
Pharmacodynamics. Verapamil is a calcium channel blocker with antiarrhythmic, antianginal and antihypertensive properties.
Verapamil reduces myocardial oxygen demand by reducing contractility and heart rate. As a result of the action of the drug, the coronary vessels of the heart expand, the coronary blood flow increases. The tone of peripheral arteries and the general peripheral vascular resistance decreases.
The drug has a therapeutic effect in supraventricular arrhythmias due to inhibition of sinus node automatism.
Verapamil is the drug of choice in the treatment of vasospastic angina. The pronounced therapeutic effect of verapamil is also noted in the treatment of other forms of angina pectoris.
Pharmacokinetics. When taking pills absorbed more than 90% of the dose of the active substance. In the liver, verapamil is metabolized. The hypotensive activity of the main metabolite, norverapamil, is less pronounced than that of unchanged verapamil. 90% of verapamil is associated with plasma proteins. When taken once a pill, the half-life is 2.8–7.4 hours; when reapplied, the half-life may be from 4.5 hours to 12 hours.
Indications for use
Verapamil is used for:
- treatment and prevention of exertional angina pectoris (otherwise - chronic stable angina pectoris), rest angina pectoris (unstable angina pectoris), vasospastic angina pectoris;
- treatment and prevention of cardiac arrhythmias - paroxysmal supraventricular tachycardia, supraventricular extrasystole, atrial fibrillation and flutter;
- therapy of hypertension.
Contraindications to the appointment of Verapamil are:
- acute heart failure;
- chronic heart failure (at stage IIB, III);
- severe bradycardia;
- atrioventricular block (grade II and III);
- synotrial blockade;
- syndromes: Morgagni-Adams-Stokes, Wolf-Parkinson-White, sick sinus;
- cardiogenic shock;
- simultaneous intravenous administration of β-blockers;
- age up to 18 years;
- hypersensitivity to the main or auxiliary components.
Dosing and Administration
Verapamil taken during or after a meal, washed down with a small amount of liquid. Doses are set individually based on the form, the severity of the pathology, the individual characteristics of the patient and the effectiveness of the treatment.
Adults for the prevention of attacks of arrhythmias, angina pectoris, and hypertension are prescribed 40–80 mg of verapamil 3-4 times a day. An increase in a single dose up to 120-160 mg is possible. The maximum daily dosage of verapamil is 480 mg.
Patients with severe functional impairment of the liver, verapamil is prescribed in minimal therapeutic doses, and the maximum allowable daily dose is 120 mg.
When using verapamil may develop undesirable side effects:
- on the part of the cardiovascular system - atrioventricular block, bradycardia, facial flushing, arterial hypotension, signs of heart failure (especially in susceptible patients while taking high doses of verapamil);
- on the part of the nervous system - headache, dizziness, lethargy, nervous irritability, fatigue;
- on the part of the digestive system - vomiting, nausea, constipation, increased activity of liver enzymes;
- allergic reactions - itching and rash;
- other reactions - peripheral edema.
With an overdose of Verapamil (taking up to 6 g of the drug), hypertension, sinus bradycardia, atrioventricular block or asystolia develops. Possible deep loss of consciousness.
For the treatment of drug poisoning, calcium gluconate, dopamine, norepinephrine or isoproterenol is injected intravenously. Depending on the clinical signs of poisoning, drugs for symptomatic therapy are prescribed. Hemodialysis in this case is not effective.
During the application of Verapamil requires mandatory monitoring of the functions of the heart, blood vessels, respiratory system.
In some pathologies, Verapamil is prescribed with caution. It:
- pronounced functional disorders of the liver (the maximum dose for such violations is 120 mg);
- the initial stages of chronic heart failure;
- atrioventricular block I degree;
- combination with β-blockers, antiarrhythmic drugs, inhalation anesthetics causes an increase in cardiotoxic action, manifested by an atrioventricular block, a sharp decrease in blood pressure and heart rhythm, heart failure;
- combination with carbamazepine and lithium preparations causes an increase in neurotoxic effects;
- combination with acetylsalicylic acid increases the risk of bleeding;
- combination with muscle relaxants enhances their action;
- simultaneous use with diuretics and antihypertensive drugs causes an increase in the hypotensive effect of verapamil;
- in combination with digoxin, its plasma concentration increases and kidney elimination worsens (plasma level of digoxin should be constantly monitored);
- in combination with quinidine, its plasma concentration increases, and, accordingly, the likelihood of severe hypotension increases;
- in combination with prazosin, theophylline, cyclosporin, their plasma concentration increases;
- Cimetidine and ranitidine increase the plasma concentration of verapamil;
- Phenobarbital and rifampicin lower plasma concentration and therapeutic effect of verapamil.
Pregnancy and lactation
For pregnant women, Verapamil is prescribed only in situations where the intended benefit to the mother exceeds the potential threat to the fetus.
Verapamil is excreted in breast milk, so for the period of treatment breastfeeding is canceled.
Structural analogues of Verapamil include preparations Finoptin, Isoptin, Isoptin CP 240, Verogalid EP 240.
Terms and conditions of storage
Verapamil is kept out of the reach of children, protected from moisture and sunlight, at temperatures up to 25 ° C. Shelf life is 3 years. Do not take pills after the expiration date indicated on the package.
Verapamil tablets 40mg, 50 tablets - 35-45 rubles.
Verapamil tablets 80mg, 50 tablets - 55-75 rubles.