Time-dependent and dose-dependent hemolytic anemia eventually associated with hyperbilirubinemia and a high reticulocyte count is the only major toxic effect associated with oral or intravenous ribavirin and is reversible on withdrawal. There was a fall in hemoglobin concentrations below In patients with Nipah virus infection there was no difference in the incidence of adverse effects between those who elected to have ribavirin treatment and those who refused.
In a randomized controlled trial of high-dose interferon alfa-2b plus oral ribavirin for 6 or 12 months in 50 patients with chronic hepatitis C, the sequential effects of treatment on hemoglobin, leukocytes, and platelets were recorded. There was a fall in hemoglobin, and the lowest concentrations were recorded after 6 months of treatment in both groups. All hematological measurements returned to normal after the end of treatment. Detailed studies of the effects of ribavirin on erythrocyte Adenosine and adenosine triphosphate content and on the hexose monophosphate shunt have been conducted in vitro.
Adenosine and adenosine triphosphate concentrations were significantly reduced and the hexose monophosphate shunt increased, suggesting erythrocyte susceptibility to oxidation. In vivo, ribavirin , alone or in combination with interferon, was associated with significant reductions in hemoglobin concentrations and a marked increase in absolute reticulocyte counts. Ribavirin -treated patients showed an increase in aggregated band 3, which was associated with significantly increased binding of auto-logous antibodies and complement C3 fragments, suggesting erythrophagocytic removal by the reticuloen-dothelial system.
Ribavirin capsules may cause fetal harm when administered to a pregnant woman. Ribavirin capsules are contraindicated in women who are or may become pregnant. Ribavirin therapy should not be started until a report of a negative pregnancy test has been obtained immediately prior to planned initiation of therapy.
Patients should use at least two forms of contraception and have monthly pregnancy tests during treatment and during the 6-month period after treatment has been stopped. Extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients.
Ribavirin has demonstrated significant teratogenic and embryocidal effects in all animal species in which adequate studies have been conducted. These effects occurred at doses as low as one twentieth of the recommended human dose of ribavirin. Ribavirin therapy should not be started until a report of a negative pregnancy test has been obtained immediately prior to planned initiation of therapy [see Boxed Warning , Contraindications 4 , Use in Specific Populations 8.
The anemia associated with ribavirin capsules occurs within 1 to 2 weeks of initiation of therapy. Because the initial drop in hemoglobin may be significant, it is advised that hemoglobin or hematocrit be obtained before the start of treatment and at Week 2 and Week 4 of therapy, or more frequently if clinically indicated. Patients should then be followed as clinically appropriate [see Dosage and Administration 2. Fatal and nonfatal myocardial infarctions have been reported in patients with anemia caused by ribavirin.
Patients should be assessed for underlying cardiac disease before initiation of ribavirin therapy. Patients with pre-existing cardiac disease should have electrocardiograms administered before treatment, and should be appropriately monitored during therapy.
Patients receiving azathioprine with ribavirin should have complete blood counts, including platelet counts, monitored weekly for the first month, twice monthly for the second and third months of treatment, then monthly or more frequently if dosage or other therapy changes are necessary [see Warnings and Precautions 5.
Use in Specific Populations 8. Category X [see Contraindications 4 ]. Malformations of the skull, palate, eye, jaw, limbs, skeleton, and gastrointestinal tract were noted. The incidence and severity of teratogenic effects increased with escalation of the drug dose. Survival of fetuses and offspring was reduced [see Contraindications 4 and Warnings and Precautions 5. Potential Risk to the Fetus Ribavirin is known to accumulate in intracellular components from where it is cleared very slowly. It is not known whether ribavirin is contained in sperm, and if so, will exert a potential teratogenic effect upon fertilization of the ova.
However, because of the potential human teratogenic effects of ribavirin, male patients should be advised to take every precaution to avoid risk of pregnancy for their female partners. Ribavirin Pregnancy Registry A Ribavirin Pregnancy Registry has been established to monitor maternal-fetal outcomes of pregnancies of female patients and female partners of male patients exposed to ribavirin during treatment and for 6 months following cessation of treatment.
Healthcare providers and patients are encouraged to report such cases by calling Because many drugs are excreted in human milk and to avoid any potential for serious adverse reactions in nursing infants from ribavirin, a decision should be made either to discontinue nursing or therapy with COPEGUS, based on the importance of the therapy to the mother.
Specific pharmacokinetic evaluations for ribavirin in the elderly have not been performed. The risk of toxic reactions to this drug may be greater in patients with impaired renal function. Discontinuation rates were higher in subjects with severe renal impairment compared to that observed in subjects with moderate renal impairment or normal renal function.
Pharmacokinetic modeling and simulation indicate that a dose of mg daily in patients with severe renal impairment and a dose of mg daily alternating with mg the following day in patients with moderate renal impairment will provide plasma ribavirin exposure similar to patients with normal renal function receiving the approved regimen of COPEGUS. These doses have not been studied in patients [see Dosage and Administration 2.
Tags: cozaar generic price oxycodone retail price buy prilosec online canada
© Copyright 2017 Ribavirin 200mg capsule price *** morbidevoci.ch.