Antiarrhythmic effect is based on a direct and local anesthetic action on membranostabilizruyuschem myocardiocytes, as well as beta-adrenergic blockade of receptors and calcium channels. Mestnoanesteziruyuschee effect approximates activity procaine. Propafenone, blocking the fast sodium channel causes a dose-dependent decrease in the depolarization trenbolone rate and depresses the phase 0 of the action potential amplitude and in Purkinje fibers and ventricular contractile fibers, inhibits automatism. Slows host the Purkinje fibers. It extends the time for carrying out the sinoatrial (SA) node and the atria. When applied elongation occurs propafenone PQ interval and extending complex QRS (15 to 25), and the intervals A-H and HV. Slowing holding the drug prolongs the effective refractory period in the atria, in atrioventricular (AV) node, additional beams, and to a lesser extent in the ventricles. Nor is there any significant changes in the QT interval. Electrophysiological effects are more pronounced in the ischemic than in normal myocardium. It has a negative inotropic effect, which usually manifests itself with a decrease in left ventricular ejection fraction below 40%. The action starts after 1 h after oral administration, reaching a maximum 2-3 hours and lasts for 8-12 hours.
Absorbed more than 95% of the formulation.Shows bioavailability of propafenone dose-dependent, which increases linearly with increasing dose: increasing from 5% to 12% with increasing single dose of 150 mg to 300 mg, and 450 mg at – 40-50%. Maximum plasma concentration achieved after oral administration for 1-3.5 hours and its concentration ranges from 500 to 1500 mg / l. The permeability of the blood-brain and placental barrier is low. The volume of distribution – 4.3 m / kg. Communication with the plasma proteins and internal organs (liver, lungs, and others.) – 85-97%. 11 describes metabolites of the drug, pharmacologically active – and 5-N-gidroksipropafenon depropilpropafenon having comparable propafenone antiarrhythmic activity. Oxidative metabolism by a specific cytochrome dependent whose activity is genetically determined. The therapeutic range propafenone plasma concentrations of 0.5-2.0 mg / l. Propafenone is almost completely metabolized. The half-life (T?) Of “fast” metabolizers – 2-10 hours, the “slow” – 10-32 hours, the biological T? Is about 6.2 hours. Excreted by the kidneys – 38% as metabolites (less than 1% unchanged), the bile – 53% (in the form of sulfates and glucuronides of metabolites and active substance). Excretion is reduced in hepatic insufficiency.
Prevention and treatment of supraventricular and ventricular arrhythmias, paroxysmal arrhythmias (supraventricular – fibrillation and atrial flutter, Wolff-Parkinson-White syndrome), atrioventricular re-entry tachycardia; prevention of stable monomorphic ventricular tachycardia.
- Hypersensitivity to the drug, and the drug’s components, digoxin intoxication;
- Severe congestive heart failure (decompensation), uncontrolled congestive heart failure;
- Cardiogenic shock (except for hypotension caused by tachycardia, and anti-arrhythmic shock);
- Severe bradycardia and severe hypotension;
- SA blockade, violation of intraatrial;
- Bundle branch block;
- Intraventricular bifastsikulyarnaya blockade and AV blockade II-III degree (without pacemaker);
- sick sinus syndrome;
- Syndrome “tachycardia-bradycardia”;
- Myocardial infarction;
- Age 18 years (effectiveness and safety have been established).Precautions : chronic trenbolone obstructive pulmonary disease (COPD), myasthenia gravis (including myasthenia gravis), heart failure (ejection fraction less than 30%), cardiomyopathy, hypotension, patients with permanent or temporary pacemaker; hepatic cholestasis, liver and / or kidney failure, a combination with others. antiarrhythmics, similar in effect on the electrophysiology of the heart, electrolyte disturbances (must always be adjusted to the purpose of propafenone), age over 70 years.
Pregnancy and lactation
The use of propafenone during pregnancy, especially during the first trimester, is only possible when the expected benefit to the mother outweighs the potential risk to the fetus.
Dosing and Administration
Inside. The tablets should be swallowed whole, after eating, squeezed small amounts of water.
Dosage is determined individually and adjusted by your doctor.
The daily dose is 450 mg (3 times a day with 150 mg every 8 hours). Produced dose-related increases gradually (every 3-4 days) to 600 mg / day in 2 doses per day or up to 900 mg / day for 3 doses.
If treatment was associated extension QRS complex or QT interval by more than 20% from baseline or elongation PQ interval of more than 50%, the elongation of the interval QT more than 500 ms, the increase in incidence and severity of arrhythmia dose should be reduced or temporarily interrupt the application propanorm.
in patients older than 70 years and in patients with weight body less than 70 kg lower doses are used (the first dose is given in a hospital under the control of ECG and blood pressure).
if abnormal liver function (cumulative effect is possible) Propanorm used at doses of 20-30% of the ordinary, with impaired renal function trenbolone (creatinine clearance less than 10 %), the initial dose – 50% of the original.