Pharmacodynamics and pharmacokinetics
Pharmacodynamics
Antiarrhythmic drug. It has a membrane-stabilizing effect, sodium channel blocker properties and slight b-adrenergic blocking activity.
It inhibits the increase in action potential, which reduces the speed of impulse transmission. The refractory period in the AV node, atrium, and ventricles increases. It also lengthens the refractory period in additional conduction pathways in individuals with Wolff-Parkinson-White syndrome.
Pharmacokinetics
The drug is a mixture of S-propafenone and R-propafenone.
The highest concentration in the blood is created 2-3 hours after administration. The active substance undergoes significant biotransformation under the influence of the CYP2D6 isoenzyme . Bioavailability depends on the dose and form of release. Quickly distributed in tissues. In almost 90% of patients, the drug undergoes rapid and significant transformation, with a half-life of 3-9 hours. There are 2 main derivatives - 5-hydroxypropafenone and N-depropylpropafenone .
In another 10% of patients, the drug is metabolized more slowly. With this type of metabolism , the half-life averages 12-30 hours.
Comparison of the effectiveness of Propanorm and Ritmonorm
Ritmonorm is more effective than Propanorm - this means that the ability of the medicinal substance to provide the maximum possible effect is different.
For example, if the therapeutic effect of Ritmonorm is more pronounced, then with Propanorm it is impossible to achieve this effect even in large doses.
Also, the speed of therapy is an indicator of the speed of the therapeutic action; Ritmonorm and Propanorm are also different, as is bioavailability - the amount of a medicinal substance reaching the place of its action in the body. The higher the bioavailability, the less it will be lost during absorption and use by the body.
Contraindications
- Brugada syndrome.
- Myocardial infarction (within 3 months).
- Severe changes in the myocardium (severe bradycardia, chronic refractory heart failure with LVEF up to 35%, sinus node weakness, cardiogenic shock, AV block, intraatrial conduction disorders, distal block, arterial hypotension.
- Severe changes in water and electrolyte balance.
- Decompensated obstructive chronic pulmonary disease.
- Concomitant use of Ritonavir .
- Myasthenia gravis.
- Age less than 18 years.
- Hypersensitivity to the components of the drug.
It is recommended to use Ritmonrm with caution in cases of atrial fibrillation , organic myocardial changes, obstructive lesions of the respiratory tract, liver or kidney dysfunction, in persons with a pacemaker, elderly patients, during pregnancy or lactation .
Side effects
- Hematopoietic disorders: leukopenia, thrombocytopenia, agranulocytosis, granulocytopenia.
- Immune disorders : blood dyscrasia, cholestasis , skin rash.
- Metabolic disorders: decreased appetite .
- Mental disorders: nightmares, anxiety, confusion, sleep disturbances.
- Nervous disorders: headache , dizziness , taste disturbance, fainting, paresthesia , lack of coordination, extrapyramidal symptoms , convulsions, anxiety.
- Visual disturbances: blurred vision.
- Hearing disorders: vertigo.
- Circulatory disorders: cardiac conduction disorders, tachycardia , palpitations, bradycardia, atrial flutter, arrhythmia, ventricular tachycardia, marked decrease in pressure, heart failure, ventricular fibrillation, decreased number of heartbeats, orthostatic hypotension.
- Respiratory disorders: shortness .
- Digestive disorders: vomiting, abdominal pain, nausea, constipation , diarrhea , dry mouth, flatulence , bloating, retching, diseases of the digestive system, liver dysfunction, cholestasis, hepatocellular disorders, jaundice, hepatitis.
- Skin disorders: skin itching , urticaria, erythema , skin rash.
- Musculoskeletal disorders: lupus-like syndrome.
- Reproductive disorders: decreased sperm count, erectile dysfunction.
- General disorders: weakness, chest pain, fever , increased fatigue.
Indications for use
- arrhythmias due to a decrease in potassium and magnesium in the blood plasma;
- arrhythmias that occurred when taking cardiac glycosides;
- extrasystolic arrhythmia;
- cardiac ischemia;
- cardiopsychoneurosis;
- myocarditis and myocardiopathy ;
- liver diseases;
- chronic fatigue syndrome (as part of complex therapy).
Instructions for use Ritmonorm (Method and dosage)
The instructions for Ritmonorm prescribe taking the tablets orally, swallowing them whole (due to the bitter taste), washing them down with liquid and without chewing.
The dosage of the drug must be selected individually, based on the patient’s response and the effect obtained. It is recommended to begin therapy in a hospital, having first stopped taking all antiarrhythmic drugs (monitoring blood pressure and ECG ).
In individuals with significantly increased QRS intervals and AV block, it is recommended to reduce the dose.
For adults weighing over 70 kg, the initial dosage is 150 mg three times a day. The dosage can be increased after 3-4 days to 300 mg twice a day, and if necessary - to a maximum dosage of 300 mg three times a day.
If the patient weighs up to 70 kg, therapy should begin with low dosages of the drug. The dosage should not be increased if the duration of use of the drug does not exceed 3-4 days.
Overdose
Signs of overdose: deterioration of sinus node automaticity, increased PQ interval, increased QRS complex, ventricular fibrillation, ventricular tachycardia, AV block, ventricular flutter, headache, blurred vision, dizziness, tremor, paresthesia, nausea, constipation, dry mouth mucous membranes, arrest breathing, coma .
Treatment of overdose
Hemodialysis is ineffective. In addition to carrying out standard emergency measures, it is necessary to monitor and adjust the main indicators in the intensive care unit. of Isoproterenol and Dopamine are effective . Seizures are usually treated with intravenous diazepam . You may also need to be connected to a ventilator and perform chest compressions.
Interaction
When used simultaneously with local anesthetics or other drugs that slow down the pulse or reduce myocardial contractility, increased side effects are possible.
Concomitant use with drugs metabolized by CYP2D6 may cause an increase in the concentration of these drugs in the blood .
An increase in the content of Metoprolol, Propranolol, Desipramine, Theophylline, Cyclosporine, Digoxin in the blood can be observed when taken together with Propafenone.
Drugs that inhibit the isoenzymes CYP1A2, CYP2D6, CYP3A4 may cause an increase in the concentration of Propafenone in the blood. When using Propafenone with blockers of these isoenzymes, patients should be monitored, and if necessary, the dose of the drug should be adjusted.
Combined treatment with Amiodarone and Propafenone can cause repolarization and conduction disturbances and be accompanied by a proarrhythmogenic effect. In this case, it may be necessary to adjust the dosages of both drugs.
The simultaneous use of Propafenone and Rifampicin reduces the concentration of the former in the blood and weakens its antiarrhythmic activity.
It is necessary to monitor the parameters of the coagulation system in patients simultaneously receiving indirect anticoagulants , since Propafenone stimulates the pharmacological action of this group of drugs and increases the prothrombin time.
With the simultaneous use of Propafenone and selective serotonin reuptake blockers, an increase in the concentration of the former in the blood is possible.
Reviews about Rhythmocore
A decrease in the level of potassium in the blood causes the development of extrasystole and tachycardia . Therefore, maintaining potassium at normal levels is important for normal cardiac function. Hypokalemia increases the toxicity of cardiac glycosides and causes an imbalance in protein balance in the body.
A decrease in magnesium levels is observed in half of patients who take diuretics and, especially often, in the elderly. Hypomagnesemia also manifests itself as heart rhythm disturbances. Correction of disorders is carried out by prescribing potassium and magnesium drugs, among which are Panangin , Rhythmocor and Asparkam . They are usually well tolerated, especially since the dosage form in capsule form significantly reduces the incidence of adverse reactions from the gastrointestinal tract . Patients note effectiveness, reasonable price, and only in some cases the development of undesirable effects.
- “... An attack of arrhythmia begins suddenly and can last more than a week. After 2 days of taking Rhythmocor everything goes away.”
- “... There was a rhythm disturbance and pain like angina pectoris. I drank it for 10 days - everything returned to normal, including the cardiogram.”
- “... Helps with extrasystole.”
- “... Itching and rash appeared on the fifth day of use.”
- “... After it I felt heaviness in the liver and stomach.”
special instructions
Therapy should be started in a hospital setting, since there is a possibility of arrhythmogenic effects caused by the use of Ritmonorm. It is necessary that previous antiarrhythmic treatment be completed before starting new therapy within a period equal to approximately 2-4 half-lives of the drugs used. Each patient must undergo an ECG and a general clinical examination before starting therapy.
Taking propafenone can reveal the hidden course of Brugada syndrome and provoke Brugada-like changes during an ECG . After starting treatment with Ritmonorm, it is recommended to perform an ECG to exclude Brugada syndrome.
In patients with pronounced changes in the myocardium when using the drug Ritmonorm, the occurrence of serious side effects cannot be ruled out.
Dizziness, blurred vision, increased fatigue and arterial hypotension disrupt the patient’s reaction speed and impair his ability to drive. During treatment with Rytmonorm you should refrain from such activities.
Comparison of safety of Propanorm and Ritmonorm
The safety of a drug includes many factors.
At the same time, in Propanorm it is quite similar to Ritmonorm. It is important where the drug is metabolized: drugs are excreted from the body either unchanged or in the form of products of their biochemical transformations. Metabolism occurs spontaneously, but most often involves major organs such as the liver, kidneys, lungs, skin, brain and others. When assessing metabolism in Propanorm, as well as in Ritmonorm, we look at which organ is the metabolizing one and how critical the effect on it is.
The risk-benefit ratio is when the prescription of a drug is undesirable, but justified under certain conditions and circumstances, with the obligatory observance of caution in use. At the same time, Propanorm does not have any risks when used, just like Ritmonorm.
Also, when calculating safety, it is taken into account whether only allergic reactions occur or possible dysfunction of the main organs. In other matters, as well as the reversibility of the consequences of using Propanorm and Ritmonorm.
Price, where to buy
The price of Ritmonorm in standard packaging in Russia is 700-1350 rubles; in Ukraine, purchasing such a drug will cost an average of 511 hryvnia.
- Online pharmacies in RussiaRussia
- Online pharmacies in UkraineUkraine
ZdravCity
- Ritmonorm tablets p.p.o.
150 mg 50 pcs. Famar Lyon 481 rub. order
Pharmacy Dialogue
- Ritmonorm (tab. p.pl/vol. 150 mg No. 50) EbbVi
510 rub. order
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