COPEGUS, ribavirin, is a nucleoside analogue with antiviral activity. The chemical name of ribavirin is 1-β-Dribofuranosyl-1H-1,2,4-triazole-3-carboxamide and has the following structural formula:
The empirical formula of ribavirin is C8H12N4O5 and the molecular weight is 244.2. Ribavirin is a white to offwhite powder. It is freely soluble in water and slightly soluble in anhydrous alcohol.
COPEGUS (ribavirin) is available as a light pink to pink colored, flat, oval-shaped, film-coated tablet for oral administration. Each tablet contains 200 mg of ribavirin and the following inactive ingredients: pregelatinized
starch, microcrystalline cellulose, sodium starch glycolate, cornstarch, and magnesium stearate. The coating of the tablet contains Chromatone-P® or Opadry® Pink (made by using hydroxypropyl methyl cellulose, talc,
titanium dioxide, synthetic yellow iron oxide, and synthetic red iron oxide), ethyl cellulose (ECD-30), and triacetin.
12 CLINICAL PHARMACOLOGY
12.1 Mechanism of Action
Ribavirin is an antiviral drug [see Microbiology (12.4)].
Mechanism of Action
The mechanism by which ribavirin contributes to its antiviral efficacy in the clinic is not fully understood.
Ribavirin has direct antiviral activity in tissue culture against many RNA viruses. Ribavirin increases the mutation frequency in the genomes of several RNA viruses and ribavirin triphosphate inhibits HCV polymerase
in a biochemical reaction. Antiviral Activity in Cell Culture In the stable HCV cell culture model system (HCV replicon), ribavirin inhibited autonomous HCV RNA replication with a 50% effective concentration (EC50) value of 11-21 mcM. In the same model, PEG-IFN α-2a
also inhibited HCV RNA replication, with an EC50 value of 0.1-3 ng/mL. The combination of PEG-IFN α-2a and ribavirin was more effective at inhibiting HCV RNA replication than either agent alone.
"Have I been negatively impacting treatment by not taking Neup shots on time?"
"I thought Riba caused low WBC"
Actually it is the interferon that is causing the drop in WBC
The growth factor(Neup) would have no bearing on the immune system It is only a bone marrow enhancement for production of white cells.Not taking it would have no effect on tx. other than possibly your ANC would be low...which in itself when doing HCV tx, has been shown to not have much impact on infection ..