Ribavirin triphosphate (RTF) is a potent inhibitor of inosine monophosphate dehydrogenase (IMP dehydrogenase), viral RNA polymerase and viral mRNA guanylyltransferase. Inhibition of the latter stops mRNA capping, resulting in significant depletion of intracellular guanosine triphosphate stores and inhibition of viral RNA and protein synthesis. Ribavirin also integrates into the viral genome, causing lethal mutations, with a subsequent reduction in the pathogenicity of the virus.
Ribavirin inhibits replication of new virions, which ensures reduction of viral load, selectively inhibits synthesis of viral RNA without suppressing RNA synthesis in normally functioning cells.
Ribavirin is effective against hepatitis C virus. Although the mechanism of action is completely unclear, it is thought that ribavirin triphosphate, which accumulates as it is phosphorylated, competitively suppresses guanosine triphosphate formation, thereby reducing viral RNA synthesis. It is also believed that the mechanism of synergistic action of ribavirin and interferon alfa-2b or peginterferon alfa-2b against hepatitis C virus is caused by the enhanced phosphorylation of ribavirin by interferon.
The DNA viruses most sensitive to ribavirin are herpes simplex virus, adenoviruses, CMV, smallpox group viruses, Marek’s disease; RNA viruses – influenza A, B, paramyxoviruses (parainfluenza, mumps, Newcastle disease), reoviruses, arenaviruses (Lassa fever virus, Bolivian hemorrhagic fever virus), bunyaviruses (Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus), hantaviruses (hemorrhagic fever virus with renal or pulmonary syndrome), oncogenic RNA viruses.
. Only when administered in prodromal period of hemorrhagic fever with renal syndrome it reduces severity of disease course, reduces duration of symptoms (fever, oliguria, pain in lumbar region, abdomen, headache), improves laboratory indexes of renal function (decreases degree of creatinine and blood urea), reduces risk of hemorrhagic complications and unfavorable results of disease.
DNA viruses insensitive to ribavirin are Varicella zoster, pseudorabies virus, natural cowpox; RNA viruses are enteroviruses, rhinoviruses, Semliki forest encephalitis virus.
Oral (in combination with interferon alpha-2b or peginterferon alpha-2b):
Chronic hepatitis C (in patients not previously treated with interferon alfa-2b or peginterferon alfa-2b;
In an exacerbation after a course of interferon alfa-2b or peginterferon alfa-2b monotherapy;
in patients who are unresponsive to interferon alfa-2b or peginterferon alfa-2b monotherapy).
ribavirin 200 mg;
dairy sugar (lactose),
How to take, the dosage
Orally, without chewing and drinking water, along with meals 0.8-1.2 g per day in 2 doses (morning and evening). Simultaneously interferon alfa-2b – subcutaneously, 3 million ME three times a week or peginterferon alfa 2b – subcutaneously, 1.5 mcg/kg once a week is prescribed. In combination with interferon alfa-2b with body weight less than 75 kg the dose of ribavirin is 1 g per day (0.4 g in the morning and 0.6 g in the evening); above 75 kg – 1.2 g per day (0.6 g in the morning and 0.6 g in the evening).
In combination with peginterferon alfa-2b with body weight less than 65 kg the dose of ribavirin is 0.8 g per day (0.4 g in the morning and 0.4 g in the evening); 65-85 kg – 1 g per day (0.4 g in the morning and 0.6 g in the evening); over 85 kg (0.6 g in the morning and 0.6 g in the evening).
The duration of treatment is 24 to 48 weeks; with at least 24 weeks for previously untreated patients and 48 weeks for patients with genotype 1 virus. In patients resistant to interferon alfa monotherapy, and also in case of relapse – at least 6 months to 1 year (depending on the clinical course of the disease and the response to ongoing therapy).
Medicinal products containing magnesium and aluminum compounds, simethicone reduce the bioavailability of the drug (AUC decreases by 14%, has no clinical significance).
When used together with interferon alpha-2b or peginterferon alpha-2b – synergism of action.
The administration of ribavirin during treatment with zidovudine and/or stavudine is accompanied by a decrease in their phosphorylation, which may lead to HIV viremia and require a change in the treatment regimen.
It increases the concentration of phosphorylated metabolites of purine nucleosides (including didanosine, abacavir) and the associated risk of lactic acidosis.
Has no effect on liver enzymatic activity involving cytochrome P450.
Simultaneous intake of food with high fat content increases the bioavailability of ribavirin (AUC and Cmax increase by 70%).
The teratogenicity of the drug should be taken into account; men and women of reproductive age should use effective contraception during treatment and for 7 months after the end of therapy.
Laboratory studies (clinical blood count with leukocyte count and platelet count, determination of electrolytes, creatinine content, liver function tests) should be performed before the start of therapy, at 2 and 4 weeks, and regularly thereafter.
In treatment with ribavirin the maximum decrease in hemoglobin is in most cases observed after 4-8 weeks from the start of treatment. If hemoglobin decreases below 110 mg/ml, the dose of ribavirin should be temporarily reduced by 400 mg per day; if hemoglobin decreases below 100 mg/ml, the dose should be reduced to 50% of the initial dose. In most cases, the recommended dose changes provide hemoglobin recovery. If hemoglobin drops below 85 mg/ml, the drug should be stopped.
In case of acute manifestation of hypersensitivity (urticaria, angioedema, bronchospasm, anaphylaxis) the drug should be stopped immediately. Transient rashes are not grounds for discontinuation of treatment.
When using the drug, those who are tired, drowsy or disoriented should refrain from driving and engaging in potentially dangerous activities requiring increased concentration and quick psychomotor reactions.
With regard to possible worsening of renal function in elderly patients, renal function, particularly creatinine clearance, should be determined before using the drug.
Hypersensitivity, pregnancy, lactation, chronic heart failure stage II6-III, myocardial infarction, renal failure (creatinine clearance less than 50 ml/min), severe anemia, liver failure, decompensated liver cirrhosis, autoimmune diseases (including autoimmune hepatitis), untreatable thyroid diseases, severe depression and suicidal intentions.autoimmune diseases (including autoimmune hepatitis), untreatable thyroid disease, severe depression with suicidal intent, childhood and adolescence (under 18).
With caution: women of childbearing age (pregnancy is undesirable), decompensated diabetes (with episodes of ketoacidosis); chronic obstructive pulmonary disease, pulmonary embolism, chronic heart failure, thyroid disease (including thyrotoxicosis).Thyrotoxicosis), blood clotting disorders, thrombophlebitis, myelodepression, hemoglobinopathy (including thalassemia, sickle cell anemia), depression, suicidal tendencies (including in anamnesis), elderly age.
Nervous system disorders: headache, dizziness, general weakness, malaise, insomnia, asthenia, depression, irritability, anxiety, emotional lability, nervousness, agitation, aggressive behavior, confusion; rarely – suicidal tendency, increased smooth muscle tone, tremor, paresthesia, hyperesthesia, hypoesthesia, fainting.
Cardiovascular system disorders: decreased or increased blood pressure, brady or tachycardia, palpitations, cardiac arrest.
Hematopoietic disorders: hemolytic anemia, leukopenia, neutropenia, granulocytopenia, thrombocytopenia; very rarely – aplastic anemia.
Respiratory system disorders: dyspnea, cough, pharyngitis, dyspnea, bronchitis, otitis media, sinusitis, rhinitis.
Digestive system disorders: dry mouth, decreased appetite, nausea, vomiting, diarrhea, abdominal pain, constipation, perversion of taste, pancreatitis, flatulence, stomatitis, glossitis, gum bleeding, hyperbilirubinemia.
Sensory organs: lacrimal gland involvement, conjunctivitis, visual impairment, hearing impairment/loss, tinnitus.
Musculoskeletal disorders: arthralgia, myalgia.
Urogenital system disorders: hot flashes, decreased libido, dysmenorrhea, amenorrhea, menorrhagia, prostatitis.
Allergic reactions: skin rash, erythema, urticaria, hyperthermia, angioedema, bronchospasm, anaphylaxis, photosensitization, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis.
Other: hair loss, conjunctivitis, alopecia, hair texture disorders, dry skin, hypothyroidism, chest pain, thirst, fungal infection, viral infection, flu-like syndrome, sweating, lymphadenopathy.
The severity of side effects may increase.
Treatment: drug withdrawal, symptomatic therapy.
|Conditions of storage|
In a dry, light-protected place at a temperature not exceeding 25 °C
Kanonfarma Production ZAO, Russia
Kanonfarma Production ZAO
Buy Ribavirin Canon, tablets 200 mg 30 pcs with delivery to USA, UK, Europe and over 120 other countries.