Instructions for Verapamil
Composition Verapamil:
1 tablet contains 240 mg of verapamil.
Pharmachologic effect Verapamil:
Verapamil is a selective class I calcium channel blocker. The main pharmacological properties of the drug are due to its ability to prevent the entry of calcium ions into cardiomyocytes and smooth muscle cells of the vascular wall through the slow calcium channels of the membrane. Verapamil has antiarrhythmic, antianginal and hypotensive activity. Reduces myocardial oxygen demand by reducing myocardial contractility and lowering heart rate. It causes the expansion of coronary arteries and an increase in coronary blood flow. The antihypertensive effect of Verapamil is associated with a decrease in the tone of the smooth muscles of the peripheral arteries and with the ability to reduce OPSS. Slowing AV conduction, Verapamil has an antiarrhythmic effect in supraventricular arrhythmias, normal heart rate remains unchanged or decreases slightly.
Verapamil also has some natriuretic and diuretic effects by reducing tubular reabsorption.
Indications Verapamil:
Paroxysmal supraventricular tachycardia (except for WPW syndrome), sinus tachycardia, atrial extrasystole, atrial fibrillation and flutter, angina pectoris (including Prinzmetal, tension, post-infarction), arterial hypertension, hypertensive hypertrophic cardiosis, idiopathy, idiopathy, idiopathy, idiopathy, idiopathy, idiopathy, idiopathy, idiopathic arthritis and idiopathic hypertrophic cardiomyopathy, idiopathic arthritis and idiopathic hypertrophic cardiomyopathy.
Contraindications Verapamil:
ardiogenic shock;
severe bradycardia;
weak sinus syndrome;
AV block II-III degree;
Wolff-Parkinson-White syndrome;
arterial hypotension;
chronic heart failure II B - stage III, acute heart failure;
hypersensitivity to the drug.
Side effects Verapamil:
From the cardiovascular system: bradycardia (less than 50 beats / min), a marked decrease in blood pressure, the development or worsening of heart failure, tachycardia; rarely, angina pectoris, up to the development of myocardial infarction (especially in patients with severe obstructive damage to the coronary arteries), arrhythmia (including ventricular fibrillation and flutter); with rapid on / in the introduction - AV block III degree, asystole, collapse.
From the side of the central nervous system and peripheral nervous system: dizziness, headache, fainting, anxiety, lethargy, fatigue, asthenia, drowsiness, depression, extrapyramidal disorders (ataxia, mask-like face, shuffling gait, stiffness of the arms or legs, trembling of the hands and fingers, difficulty swallowing).
From the digestive system: nausea, constipation (rarely diarrhea), gingival hyperplasia (bleeding, soreness, swelling), increased appetite, increased activity of hepatic transaminases and alkaline phosphatase.
Allergic reactions: pruritus, skin rash, hyperemia of the skin of the face, erythema multiforme exudative (including Stevens-Johnson syndrome).
Other: weight gain, very rarely - agranulocytosis, gynecomastia, hyperprolactinemia, galactorrhea, arthritis, transient loss of vision with Cmax, pulmonary edema, asymptomatic thrombocytopenia, peripheral edema.
Interaction Verapamil:
The simultaneous use of verapamil and beta-blockers, antiarrhythmic drugs, inhalation anesthesia drugs can lead to a mutual strengthening of their cardiodepressive effects (AV block, bradycardia, hypotension, heart failure). With simultaneous use with quinidine in patients with hypertrophic obstructive cardiomyopathy, severe hypotension and pulmonary edema may develop.
With the simultaneous administration of Verapamil with other antihypertensive drugs, mutual potentiation of their effects is noted. Verapamil is able to significantly increase the concentration of digoxin in plasma, which requires a reduction in the dose of cardiac glycoside when used together. The neurotoxic effect of Verapamil is potentiated by carbamazepine and lithium salts, and the psychotropic effect of lithium when co-administered with verapamil is weakened. The concentration of cyclosporine or theophylline in blood plasma increases when used together with verapamil. Rifampicin, phenytoin, phenobarbital and cimetidine are able to reduce the concentration of verapamil in the plasma and reduce the effectiveness of the latter. Verapamil potentiates the effect of muscle relaxants.
How to take, course of administration and dosage Verapamil:
The dosage regimen of verapamil hydrochloride is set individually. Adults are prescribed in an initial dose of 40-80 mg 3 times a day. The maximum daily dose is 480 mg. Children aged 6-14 years are prescribed 80-360 mg per day, children under 6 years of age - 40-60 mg per day; frequency of use 3-4 times a day. Tablets are taken with meals or immediately after meals with a little water.
Overdose Verapamil:
Symptoms: bradycardia, AV block, marked decrease in blood pressure, heart failure, shock, asystole, SA block.
Treatment: with early detection - gastric lavage, activated charcoal; in case of rhythm and conduction disturbance - iv isoprenaline, norepinephrine, atropine, 10-20 ml of 10% calcium gluconate solution, artificial pacemaker; iv infusion of plasma substituting solutions.
To increase blood pressure in patients with IHSS, alpha-adrenostimulants (phenylephrine) are prescribed; isoprenaline and norepinephrine should not be used.
Hemodialysis is ineffective.
Special instructions Verapamil:
With caution, the drug is prescribed for patients with impaired liver function, with acute myocardial infarction. The use of verapamil during pregnancy is possible only if the intended benefit to the mother outweighs the potential risk to the fetus. When using the drug during lactation, the issue of stopping breastfeeding should be decided.
Verapamil is prescribed with caution to patients involved in potentially dangerous activities requiring increased attention and speed of motor and mental reactions.