REBETOL is Schering Corporation's brand name for ribavirin, a synthetic nucleoside analogue (purine analogue). The chemical name of ribavirin is 1-?-D-ribofuranosyl-1H-1,2,4-triazole-3-carboxamide and has the following structural formula (see Figure 1).

PegIntron, peginterferon alfa-2b, Powder for Injection is a covalent conjugate of recombinant alfa-2b interferon with monomethoxy polyethylene glycol (PEG). The average molecular weight of the PEG portion of the molecule is 12,000 daltons. The average molecular weight of the PegIntron molecule is approximately 31,000 daltons. The specific activity of peginterferon alfa-2b is approximately 0.7 x 108 IU/mg protein.

REBETOL (ribavirin, interferon alfa-2b, recombinant)

VIRAZOLE is a brand name for ribavirin, a synthetic nucleoside with antiviral activity. VIRAZOLE (ribavirin) for inhalation solution is a sterile, lyophilized powder to be reconstituted for aerosol administration. Each 100 mL glass vial contains 6 grams of ribavirin, and when reconstituted to the recommended volume of 300 mL with sterile water for injection or sterile water for inhalation (no preservatives added), will contain 20 mg of ribavirin per mL, pH approximately 5.5. Aerosolization is to be carried out in a Small Particle Aerosol Generator (SPAG-2) nebulizer only.

COPEGUS, ribavirin, is a nucleoside analogue with antiviral activity. The chemical name of ribavirin is 1-?-Dribofuranosyl-1H-1,2,4-triazole-3-carboxamide and has the following structural formula: