Pharmacological properties
Pharmacodynamics. Rimantadine hydrochloride is a derivative of amantadine, has a pronounced antiviral activity. It is effective against various influenza A viruses, and also exhibits an antitoxic effect in influenza caused by type B viruses. Rimantadine inhibits virus replication in the early stages of the cycle by disrupting the formation of the viral envelope. Genetic studies have shown that a specific protein of the M2 gene of the virion plays an important role in the antiviral effect of rimantadine against influenza A viruses. In vitro, rimantadine inhibits the replication of all three antigenic subtypes (H1N1, H2N2, H3N3) of the influenza virus identified in humans. Rimantadine does not affect the immunogenic properties of the inactivated influenza A vaccine.
Remantadine is also effective against arboviruses, which are the causative agents of tick-borne encephalitis.
Pharmacokinetics. After single or multiple administration of the drug by patients of different age groups, no correlation has been established between the concentration of rimantadine in blood plasma and its antiviral activity.
Absorption: After oral administration, the drug is almost completely absorbed.
Distribution. After a single oral dose of Remavir at a dose of 100 mg, the average plasma concentration is 74 ng/ml (range 45 to 138 ng/ml) - in healthy adult patients aged 20-44 years, it is reached after 5-7 hours.
Approximately 40% of Remavir is bound to plasma proteins, mainly albumin. T½ of a single dose in this study group averages 25 hours, and in patients aged 71-79 years - an average of 32 hours.
Metabolism: Remavir is extensively metabolized in the liver by hydroxylation, conjugation, and glucuronidation.
Excretion. Three hydroxylated metabolites have been identified in plasma. These and other metabolites account for 74 ± 10% of a single 200 mg dose. The drug is excreted as metabolites in the urine within 72 hours. Less than 25% of the drug is excreted in the urine as unchanged drug.
In renal failure, the concentration of metabolites of Remavir in the blood plasma increases. The dose of rimantadine should be reduced by 50% if creatinine clearance is 5-29 ml/min. Chronic kidney disease does not significantly affect the pharmacokinetics of rimantadine.
The pharmacokinetics of the drug in children are close to the pharmacokinetics in adults.
Indication
Tablets. early treatment of disease caused by influenza A viruses in adults and children over 10 years of age. prevention of influenza A during an epidemic in adults and children over 10 years of age.
Capsules. Early treatment of disease caused by influenza A viruses in adults and children over 10 years of age. Prevention of influenza A during an epidemic in adults and children over 10 years of age.
Powder. Prevention and treatment of influenza A in the early stages of the disease in children over 1 year of age.
Application
The tablets are taken orally after meals, with water. Remavir should be started immediately after the first symptoms of flu appear. The therapeutic effect is more pronounced if the drug is started within the first 48 hours after the first symptoms of flu appear.
Treatment of influenza: adults and children over 10 years old - 100 mg (2 tablets) 2 times a day.
Before using the drug in children, be sure to consult a doctor.
Elderly patients (65 years old) - 100 mg (2 tablets) once a day.
The duration of the treatment course is 5 days.
Flu prevention: adults and children over 10 years old - 100 mg (2 tablets) 2 times a day.
Elderly patients or those at high risk of complications - 100 mg (2 tablets) once a day.
The use of the drug is recommended from the beginning of the flu epidemic and during the epidemic, but not more than 2 weeks.
The capsules are taken orally, after meals, with water. The capsule should not be chewed.
Remavir should be started as early as possible, immediately after the first symptoms of influenza appear. The therapeutic effect is more pronounced if the drug is started within the first 48 hours after the first symptoms of influenza appear.
Treatment of influenza: adults and children over 10 years of age - 100 mg 2 times a day.
Before using the drug in children, be sure to consult a doctor.
Elderly patients (65 years old) - 100 mg once a day.
The duration of the treatment course is 5 days.
Flu prevention: adults and children over 10 years old - 100 mg 2 times a day.
Elderly patients or those at high risk of complications - 100 mg once a day.
The use of the drug is recommended from the beginning of the flu epidemic and during the epidemic, but not more than 2 weeks.
Powder. When flu symptoms appear (fever, muscle pain, headache, eye pain), you should start taking Remavir 20 mg as soon as possible. The therapeutic effect is more pronounced if the drug is started within the first 48 hours of the onset of the disease. Dissolve the contents of the sachet in ½ glass of warm water and take orally after meals.
Treatment. Children aged 1 to 10 years are prescribed 5 mg/kg of body weight per day in 2-3 doses, but not more than 100 mg of the drug Remavir (5 sachets) per day. Children aged 11 to 14 years - 140-160 mg of the drug (7-8 sachets) per day in several doses. Children over 14 years old are prescribed adult doses (Remavir tablets at a dose of 50 mg are used). The duration of the course of treatment is 5 days.
Tablets and capsules. Hypersensitivity to rimantadine, derivatives of the adamantane group and excipients of the drug. Acute and chronic liver and kidney diseases. Thyrotoxicosis.
Powder. Hypersensitivity to rimantadine or auxiliary components of the drug, acute liver diseases, acute and chronic kidney diseases, thyrotoxicosis. The drug contains aspartame - a source of phenylalanine. Its use is contraindicated in patients with phenylketonuria.
Side effects
The drug is usually well tolerated.
Classification of adverse reactions by frequency of development: very common (≥1/10); common (≥1/100 to 1/10); uncommon (≥1/1000 to 1/100); rare (≥1/10,000 to 1/1000); very rare (1/10,000).
Gastrointestinal tract: often - dyspepsia (nausea, vomiting); infrequently - abdominal pain, diarrhea, indigestion, dry mouth, anorexia.
From the nervous system: often - insomnia; rarely - impaired concentration, dizziness, headache, increased fatigue, tremor, hallucinations, convulsions, confusion, ataxia (impaired coordination of movements), drowsiness, increased excitability, depression, euphoria, hyperkinesis (spontaneous movements), change / loss of taste, parosmia.
On the part of the heart: infrequently - palpitations, heart failure, edema, cardiac conduction disorders (blockades), tachycardia.
Vascular disorders: infrequently - hypertension, cerebrovascular disorders, fainting.
From the genitals and mammary glands: infrequently - galactorrhea.
From the vestibular apparatus and organ of hearing: infrequently - noise/ringing in the ears.
From the respiratory system, chest organs and mediastinum: infrequently - cough, shortness of breath, bronchospasm.
Skin and subcutaneous tissue disorders: infrequently - rash, itching, urticaria.
On the part of the immune system: infrequently - pallor of the skin, possible hypersensitivity reactions, including skin rashes, itching, urticaria.
General disorders: infrequently - asthenia (weakness), exacerbation of concomitant chronic diseases, increased fatigue.
Usually, side effects disappear after you stop taking the drug.
Special instructions
Remavir is prescribed with caution to patients with gastrointestinal diseases, liver dysfunction, severe heart diseases and heart rhythm disorders, and the elderly. In these cases, a dose reduction is recommended.
If there is a history of epilepsy and anticonvulsant therapy, the risk of developing an epileptic seizure increases when using rimantadine. In this case, the dose of rimantadine is reduced to 100 mg/day. If a seizure develops, the drug is discontinued.
The emergence of viruses resistant to the drug is possible.
Tablets and capsules contain lactose, therefore patients with rare hereditary forms of galactose intolerance, lactase deficiency or glucose-galactose malabsorption syndrome should not use this medicine.
Pregnancy and breastfeeding. Remavir penetrates the placental barrier and into breast milk, so the use of the drug during this period is contraindicated.
Children: Tablets and capsules can be used in children aged 10 years and over.
Powder. The efficacy and safety of the drug in children under 1 year of age have not been established, therefore the drug in this dosage form is not used in children aged 1 to 14 years.
The ability to influence the reaction rate when driving vehicles or working with other mechanisms. When using the drug, you should refrain from driving vehicles and working with potentially dangerous mechanisms.
Interactions
Paracetamol and acetylsalicylic acid reduce the effectiveness of Remavir.
Remavir reduces the effectiveness of antiepileptic drugs.
Remavir enhances the stimulating effect of caffeine.
Cimetidine may enhance the effects of Remavir.
During treatment, you should refrain from drinking alcoholic beverages, as this may cause undesirable side effects on the CNS.
Overdose
In cases of overdose - symptomatic therapy to maintain vital body functions.
There is information about a case of poisoning with a chemical analogue - amantadine.
Symptoms: agitation, hallucinations, heart rhythm disturbances, fever, chills, increased sweating, arrhythmia, hypoesthesia, increased lacrimation, dysphagia, constipation, increased urination, stomatitis, eye pain.
Treatment: drug withdrawal, gastric lavage, administration of physostigmine to children at a dose of 0.5 mg, repeated administration if necessary, but not more than 2 mg/h. Rimantadine and amantadine are removed by hemodialysis.
Storage conditions
In a dry place at a temperature not exceeding 25 °C.
