Anemia ribavirin

Ribavirin is not incorporated into the DNA or RNA of either mammalian or viral systems. It has been shown (123), however, that a high dosage of ribavirin given over a prolonged period to Rhesus monkeys results in anemia of red blood cells. This effect is dose related and reversible upon cessation of treatment. Guanosine partially reverses the antiviral effect of ribavirin against certain vimses. 

Ribavirin causes a dose-related hemolytic anemia. Once treatment has been initiated, the hemoglobin concentration may... 

About 10% to 25% of patients treated with interferon and ribavirin require dosage reductions when hemoglobin levels decrease or they develop intolerable symptoms such as shortness of breath or severe fatigue. If warranted, erythropoietin may be used as adjunctive therapy for ribavirin-induced hemolytic anemia.45... 

Monitor serum creatinine because patients with renal insufficiency (CrCl less than 50 mL/minute) may have reduced ribavirin elimination resulting in increased drug accumulation and toxicity (e.g., hemolytic anemia). 

Common side effects of peginterferon are given in Table 25-10. Common side effects of ribavirin are fatigue, flu-like symptoms, neutropenia, thrombocytopenia, and anemia. 

Tablets/Capsules/Oral solution Ribavirin may cause birth defects or death of the exposed fetus. Ribavirin is contraindicated in women who are pregnant or in men whose female partners are pregnant (see Warnings), in patients with a history of hypersensitivity to ribavirin or any component of the drug, and in patients with hemoglobinopathies (eg, thalassemia major, sickle-cell anemia).

Capsules/Tablets/Oral solution-There are significant adverse events caused by ribavirin capsules/interferon alfa-2b or peginterferon alfa-2b therapy, and ribavirin tablets/peginterferon alfa-2a therapy, including severe depression and suicidal ideation, hemolytic anemia, suppression of bone marrow function, autoimmune and infectious disorders, pulmonary dysfunction, pancreatitis, and diabetes. 

Capsules/Tablets/Oral solution - Fatal and nonfatal Mis have been reported in patients with anemia caused by ribavirin. 

Capsules/Tablets/Oral solution-The primary toxicity of ribavirin is hemolytic anemia, which occurs within 1 to 2 weeks of initiation of therapy. 

Use with ribavirin Ribavirin may cause birth defects and/or death of the fetus. Extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients. Ribavirin causes hemolytic anemia. The anemia associated with ribavirin therapy may result in a worsening of cardiac disease. Ribavirin is genotoxic and mutagenic and should be considered a potential carcinogen. 

Bone marrow toxicity Peginterferon alfa-2a suppresses bone marrow function and may result in severe cytopenias. Ribavirin may potentiate the neutropenia and lymphopenia induced by alpha interferons including peginterferon alfa-2a. Alpha interferons may be associated with aplastic anemia very rarely. 

Anemia Ribavirin caused hemolytic anemia in 10% of peginterferon alfa-2b/ribavirin capsule-treated patients within 1 to 4 weeks of initiation of therapy. Obtain complete blood counts pretreatment and at weeks 2 and 4 of therapy or more frequently if clinically indicated. 

Most adverse effects associated with aerosol ribavirin are local. Pulmonary function may decline if aerosol ribavirin is used in adults with chronic obstructive lung disease or asthma. Deterioration of pulmonary and cardiovascular function has also been seen in severely ill infants given this preparation. Rash, conjunctivitis, and rare cases of anemia have been reported. Health care workers exposed to aerosol ribavirin during its adminis-... 

Ribavirin is contraindicated in patients with sickle cell anemia and other hemoglobinopathies because of its propensity to cause anemia. Similarly, persons with coronary disease should not use ribavirin, because anemia may cause deterioration of cardiac function. Oral ribavirin should not be given to individuals with severe renal impairment no dosage adjustment is necessary for the inhaled formulation. However, patients with hepatic impairment may require dosage adjustment. 

D. Interferons and ribavirin are both likely to cause anemia the combination of these two agents increases this possibility. Interferons do not stimulate lymphocyte proliferation. 

Anemia may occur if ribavirin therapy exceeds 7 days. 

Subsequent analysis of stored serum samples showed reduction of HCV RNA levels during treatment and durable eradication of virus in some cases [38]. These early results were confirmed by randomized controlled trials in patients with chronic hepatitis C [39-41]. Durable viral eradication (termed sustained virologic response, or SVR) was achieved in 6% to 15% of patients after six months of treatment with recombinant interferon at doses of 3 to 6 MU administered subcutaneously three times per week. SVR increased to 13% to 25% if treatment was extended to 12 months [41]. The combination of the oral nucleoside analogue ribavirin with recombinant interferon increased SVR to 41% [42-44]. Ribavirin, however, is potentially embryotoxic and induces a dose-dependent hemolytic anemia, a situation that calls for close monitoring during therapy. 

Zidovudine NRTI1 200 mg tid or 300 mg bid3 Macrocytic anemia, neutropenia, nausea, headache, insomnia, asthenia Avoid concurrent stavudine and myelosuppressive drugs (eg, ganciclovir, ribavirin)... 

Approximately 10-20% of patients experience a dose-dependent hemolytic anemia that may be dose-limiting. Other side effects are depression, fatigue, irritability, rash, cough, insomnia, nausea, and pruritus. Absolute contraindications to ribavirin therapy include anemia, end-stage renal failure, severe heart disease, and pregnancy. Ribavirin is both teratogenic in animals and mutagenic in mammalian cells. 

Adverse effects Side effects reported for oral or parenteral use of ribavirin have included dose-dependent transient anemia in Lassa fever victims. Elevated bilirubin has been reported. The aerosol may be safer, although respiratory function in infants can deteriorate quickly after initiation of aerosol treatment and therefore, monitoring is essential. Because of teratogenic effects in experimental animals, ribavirin is contraindicated in pregnancy. 

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