Ribavirin
Ribavirin is a synthetic analogue of nucleosides with a pronounced antiviral effect. It has a wide spectrum of activity against various DNA and RNA viruses.
Ribavirin is effective against the hepatitis C virus. The mechanism of the synergistic effect of ribavirin and interferon alfa-2b or peginterferon alfa-2b against the hepatitis C virus has also been identified, which is due to increased phosphorylation of ribavirin by interferon.
The most sensitive to ribavirin are :
DNA viruses: herpes simplex virus, adenoviruses, cytomegalovirus, smallpox group viruses, Marek's disease;
RNA viruses - influenza A, B viruses, paramyxoviruses (parainfluenza, mumps, Newcastle disease), reoviruses, arenaviruses (Lassa fever virus, Bolivian hemorrhagic fever), bunyaviruses (Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus), hantaviruses (hemorrhagic fever virus with renal or pulmonary syndrome) paramyxoviruses, oncogenic RNA viruses.
Insensitive to ribavirin:
DNA viruses: Varicella zoster, pseudorabies virus, cowpox virus;
RNA viruses - enteroviruses, rhinoviruses, Semliki forest encephalitis virus.
Pharmachologic effect:
Antiviral agent.Indications:
- Chronic hepatitis C (in combination with interferon alfa-2b or peginterferon alfa-2b): in patients not previously treated with interferon alfa-2b or peginterferon alfa-2b;
- during exacerbation after a course of monotherapy with interferon alfa-2b or peginterferon alfa-2b; in patients refractory to monotherapy with interferon alfa-2b or peginterferon alfa-2b.
Contraindications:
Hypersensitivity, pregnancy, lactation, chronic heart failure, myocardial infarction, renal failure (creatinine clearance less than 50 ml/min), severe anemia, severe liver failure, decompensated liver cirrhosis, autoimmune diseases (including autoimmune hepatitis), untreatable thyroid disease, severe depression with suicidal intentions, childhood and adolescence (up to 18 years).
Dosing and Administration:
Ribavirin is taken orally without chewing and washed down with water, along with meals, 0.8-1.2 g per day in 2 divided doses (morning and evening). At the same time, interferon alfa-2b is prescribed subcutaneously, 3 million IU 3 times a week, or peginterferon alfa 2b is prescribed subcutaneously, 1.5 mcg/kg once a week. When combined with interferon alfa-2b for body weight up to 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). When combined with peginterferon alfa-2b for a 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); more than 85 kg - 1.2 g per day (0.6 g in the morning and 0.6 g in the evening). Duration of treatment - 24-48 weeks; at the same time, for previously untreated patients - at least 24 weeks, for patients with genotype 1 virus - 48 weeks. In patients refractory to interferon alpha monotherapy, as well as in case of relapse, at least 6 months to 1 year (depending on the clinical course of the disease and response to therapy).