Verapamil hydrochloride

General characteristics. Structure:

Active ingredient: 5 mg of verapamil of a hydrochloride in 2 ml of solution.

Excipients: sodium chloride, citric acid, solution of sodium of hydroxide of 1 M, acid solution of hydrochloric 0,1 M, water for injections.

Pharmacological properties:

Pharmacodynamics. Verapamil has anti-anginal, hypotensive, antiarrhytmic effect.

Blocks calcium channels and lowers transmembrane calcic current. Reduces contractility, frequency of a pacemaker of a sinus node and speed of carrying out in an AV node, sinuatrial and AV conductivity, weakens unstriated muscles (more arterioles, than veins), causes a peripheral vazodilatation, lowers the general peripheric vascular resistance, reduces an afterload. Increases perfusion of a myocardium, reduces a disproportion between requirement and supply of heart with oxygen, promotes regress of a hypertrophy of a left ventricle, lowers arterial pressure. Prevents development and eliminates a spasm of coronary arteries at alternative stenocardia. At patients with an uncomplicated hypertrophic cardiomyopathy improves outflow of blood from ventricles. Reduces the frequency and expressiveness of headaches of vascular genesis.

Antiarrhytmic action develops in 1-5 min. after intravenous administration, hemodynamic effects - within 3-5 min.

Pharmacokinetics. At intravenous administration an elimination half-life two-phase: early - about 4 min., final - 2 - 5 hours. Contacts proteins of plasma for 90%. It is metabolized in a liver with formation of the norverapamil having 20% of hypotensive activity of verapamil, and 11 other metabolites (are defined in trace quantities).

It is removed preferential by kidneys, partially - with excrements (16%). Gets into breast milk, passes through a placenta. At heavy abnormal liver functions the plasma clearance decreases by 70%, and the elimination half-life increases to 14 - 16 h.

Indications to use:

Treatment of Bouveret's supraventricular disease, trembling and fibrillation of ventricles.

Route of administration and doses:

Verapamil is entered intravenously slowly (under control of arterial pressure, an electrocardiography, heart rate). For stopping of attacks of tachycardia enter intravenously struyno (within not less than 2 min.) 2 - 4 ml of 0,25% of solution (5 - 10 mg of verapamil). If necessary, for example, at a Bouveret's disease, 5-10 minutes later 5 more mg can be entered.

Single dose for children at the age of 1-15 years - 0,1 - 0,3 mg/kg (2-5 mg).

Elderly: the dose has to be entered within 3 minutes for the purpose of minimization of risk of side effects.

Dosing at an abnormal liver function and kidneys: at a liver and renal failure action of one dose of intravenously entered medicine should not amplify, but duration of its action can last.

Features of use:

With care apply verapamil at patients with the expressed abnormal liver functions, at an acute myocardial infarction, an atrioventricular block of the I degree; at diseases with neuromuscular transmission disturbance (a myasthenia, Lambert-Eaton's syndrome, muscular dystrophy of Dyushenn).

At patients with dysfunction of a left ventricle, verapamil should be applied only after heart failure is managed the corresponding pharmacotherapy.

Pregnancy and lactation. Use of Verapamil at pregnancy is possible only in that case when the expected advantage for mother exceeds potential risk for a fruit. In need of use in the period of a lactation (breastfeeding) it is necessary to consider that verapamil can be emitted with breast milk.

Influence on ability to driving of motor transport and to control of mechanisms. After reception of verapamil individual reactions (drowsiness, dizzinesses) influencing ability of the patient to perform the work requiring special attention and speed of psychomotor reactions are possible.

Side effects:

From cardiovascular system: face reddening; at use in high doses, especially at predisposed patients, the expressed bradycardia, an atrioventricular block, arterial hypotension, emergence of symptoms of heart failure are possible. At bystry intravenous administration in isolated cases - a full cross heart block, an asystolia, a collapse.

From the alimentary system: nausea, locks; in some cases - tranzitorny increase in activity of hepatic transaminases in a blood plasma, reversible increase in an alkaline phosphatase.

From the central nervous system: dizziness, headache; seldom - nervousness, block, increased fatigue, an extrapyramidal syndrome.

Allergic reactions: skin rash, itch, bronchospasm, Stephens-Johnson's syndrome.

Skin and hypodermic klechatka: erythema, hyperhidrosis.

At use during the long time – a gynecomastia at men, a hyperplasia of gums, it is completely reversible after medicine cancellation.

Interaction with other medicines:

Increases level in plasma of digoxin, cyclosporine, theophylline, carbamazepine, reduces - a lity.

Weakens antibacterial activity of rifampicin, the depriving of bonuses effect of phenobarbital, reduces clearance of a metoprolol and propranolol, strengthens action of muscle relaxants. Rifampicin, Sulfinpyrazonum, phenobarbital, calcium salts, vitamin D - weaken action.

The hypotensive effect is strengthened by anti-hypertensive drugs (diuretics, vazodilatator), tricyclic and tetracyclic antidepressants and neuroleptics: anti-anginal - nitrates.

Beta adrenoblockers, IA class antiaritmik, cardiac glycosides, inhalation anesthetics, radiopaque substances exponentiate (mutually) oppressing influence on automatism of a sinuatrial node, AV conductivity and contractility of a myocardium.

At simultaneous use of verapamil with acetylsalicylic acid – increase in risk of bleeding. Cimetidinum increases the content of verapamil in plasma.

Verapamil can increase plasma concentration of Prazozinum and terazozin which can have the additive hypotensive effect, Glibenclamidum, a buspiron and a medical azolama, an atorvastatina, a lovastatina and a simvastatina.

Erythromycin, кларитромицин can increase concentration in verapamil plasma.

Verapamil can lead to colchicine influence strengthening, the combined use is not recommended.

Contraindications:

The myocardial infarction complicated by bradycardia a sick sinus syndrome, cardiogenic shock, antrioventrikulyarnaya-blockade of II and III degrees, WPW syndrome, the expressed arterial hypotension or a left ventricular failure, chronic heart failure of PB-Sh of a stage, an acute heart failure, bradycardia less than 50 beats/min, hypotension – the ABP systolic less than 90 mm Hg; simultaneous intravenous administration of beta-blockers, hypersensitivity to verapamil.

Overdose:

Symptoms: bradycardia, an atrioventricular block, the expressed lowering of arterial pressure, heart failure, shock, an asystolia, SA blockade.

Treatment: at disturbance of a rhythm and conductivity - intravenous изопреналин, Norepinephrinum, atropine, 10 - 20 ml of 10% of solution of calcium of a gluconate, an artificial pacemaker; intravenous infusion of plasma substituting solutions. For increase in arterial pressure at patients of GOKMP appoint alpha адреностимуляторы (Phenylephrinum); it is not necessary to apply изопреналин and Norepinephrinum. The hemodialysis is inefficient. Calcium is a specific antidote (10-20 ml of 10% of solution of a gluconate of calcium intravenously), if necessary to repeat an injection or to enter continuous infusion (for example, 5mmol/hour).

Storage conditions:

In the place protected from light, at a temperature not above 25 °C. To store in the place, unavailable to children. A period of validity - 2 years. Medicine should be used before the date specified on packaging.

Issue conditions:

According to the recipe

Packaging:

In ampoules on 2 ml. Packaging No. 10, No. 10х1.