Quinidine - instructions for use, dose, side effects, contraindications

Clinical and pharmacological group: & nbsp

Included in the formulation

АТХ:

C.01.B.A.01 Quinidine

Pharmacodynamics:

The alkaloid of the cinchona bark, blocks the fast sodium channels of the cell membrane,as a result of which the rapid depolarization rate in phase 0 decreases, as a result of which the conductivity of Purkinje fibers, the atrioventricular node and the myocardium decreases. The blockade of sodium channels leads to a slowing down of the slow spontaneous depolarization in phase 4, which leads to a decrease in the automatism of the conduction system of the heart. It also blocks potassium channels, slowing the process of repolarization and increasing the duration of the action potential. As a result, the effective refractory time is extended period.

It does not affect the sinoatrial node, but it has anticholinergic action (inhibits the transmission of excitation from the vagus nerve), due to which it can cause mild tachycardia and an increase in the automatism of the sinoatrial node.

Expands peripheral vessels by blocking α-adrenoreceptors and reduces myocardial contractility, which leads to a moderate decrease in blood pressure.

Pharmacokinetics:

After oral administration, fasting to 70-80% is absorbed in the gastrointestinal tract. The maximum concentration in the blood plasma is achieved in 2-3 hours. The connection with plasma proteins is 60-80%.

Metabolism in the liver.

The half-life is 6-7 hours.Elimination by the kidneys.

Indications:

It is used to treat the constant and paroxysmal form of atrial fibrillation, extrasystole. Used to prevent paroxysmal supraventricular and ventricular tachycardia, ventricular fibrillation, and also to maintain sinus rhythm after cardioversion.

ICD-10

IX.I30-I52.I45.6 Syndrome of premature agitation

IX.I30-I52.I47.2 Ventricular tachycardia

IX.I30-I52.I47.1 Nadzheludochkovaya tachycardia

IX.I30-I52.I48 Atrial fibrillation and flutter

IX.I30-I52.I49.0 Fibrillation and flutter of the ventricles

IX.I30-I52.I49.4 Other and unspecified depolarization

Contraindications:

Atrioventricular blockade of II and III degree, cardiogenic shock, glycoside intoxication with conduction disturbance, myasthenia gravis, left and right bundle bundle blockage, thrombocytopenic purpura in history with quinine or quinidine, individual intolerance, children under 18 years of age.

Carefully:

Dysfunction of the liver and kidneys, decompensated heart failure, hypotension, incomplete atrioventricular blockade, congenital lengthening of the QT interval, myocarditis, glaucoma,bronchial asthma, emphysema, myopathy, prostate adenoma, infectious diseases with fever, psoriasis, hyperthyroidism, hypersensitivity.

Pregnancy and lactation:

Recommendations for FDA - Category C. Contraindicated in pregnancy and lactation.

Dosing and Administration:

Inside for 1 hour or 2 hours after eating 200-300 mg 3-4 times a day. If necessary, the dose can be increased to 600 mg.

Intramuscularly, with an initial trial dose of 95 mg, then (in the absence of idiosyncrasy) to 190-380 mg every 2-4 hours.

The highest daily dose: 4 g; when administered intramuscularly - 3 g.

The highest single dose: 600 mg.

Side effects:

Central and peripheral nervous system: dizziness, asthenia, confusion.

Hemopoietic system: anemia, thrombocytopenia.

The cardiovascular system: arterial hypotension, decreased myocardial contractility, intracardiac block, ventricular rhythm disorders such as pirouette, asystole, ventricular fibrillation.

Digestive system: bitter taste in the mouth, anorexia, gastralgia, nausea, vomiting, diarrhea, hepatitis.

Musculoskeletal system: myasthenia gravis.

Dermatological reactions: lupus-like syndrome, itching, rash.

Sense organs: ringing in the ears, hearing and visual impairment.

Allergic reactions.

Overdose:

Quinidine shock: asystole, severe disturbances in the rhythm of the ventricles, arterial hypotension, diplopia, atrial flutter with ventricular tachycardia.

Treatment is symptomatic, hemodialysis is effective.

Interaction:

Strengthens the action of drugs that block neuromuscular transmission.

With simultaneous use with tricyclic antidepressants, the half-life of imipramine, trimipramine, desipramine, nortriptyline increases, which increases the risk of developing toxic reactions.

Amyloride reduces the effectiveness of quinidine. When used simultaneously with amiloride, ventricular arrhythmia may develop as a pirouette.

Strengthens the effect of anticoagulants, muscle relaxants.

Reduces the effect of anti-asthma.

Cimetidine prolongs the half-elimination period of quinidine.

With the simultaneous application of ranitidine, the risk of developing ventricular extrasystoles in the type of bigeminy increases.

Increase the toxicity of substances alkalinizing urine: antacid agents containing calcium or magnesium,inhibitors of carbonic anhydrase, citrates, sodium bicarbonate.

Anticholinesterase drugs and potassium preparations strengthen the effect.

Anticonvulsants (phenobarbital, primidon, phenytoin) reduce the concentration of quinidine in the blood plasma.

Special instructions:

Monitoring of hemodynamic parameters, peripheral blood patterns, electrocardiograms: QT and PQ intervals, QRS complex.

Before surgery, anesthesiologists should be warned about taking quinidine.

In the treatment it is not recommended to drive vehicles and work with moving mechanisms.

Instructions

Quinidine (Chinidinum)