Statins may improve this combinations efficacy in treating hepatitis C. Ribavirin is the only known treatment for a variety of viral hemorrhagic fevers, including Lassa fever, Crimean-Congo hemorrhagic fever, Venezuelan hemorrhagic fever, and Hantavirus infection, although data regarding these infections are scarce and the drug might be effective only in early stages. It is noted by the USAMRIID that "Ribavirin has poor in vitro and in vivo activity against the filoviruses (Ebola and Marburg) and the flaviviruses (dengue, yellow fever, Omsk hemorrhagic fever, and Kyasanur forest disease)" The aerosol form has been used in the past to treat respiratory syncytial virus-related diseases in children, although the evidence to support this is rather weak.It has been used (in combination with ketamine, midazolam, and amantadine) in treatment of rabies.Experimental data indicate that ribavirin may have useful activity against canine distemper and poxviruses. Ribavirin has also been used as a treatment for herpes simplex virus. One small study found that ribavirin treatment reduced the severity of herpes outbreaks and promoted recovery, as compared with placebo treatment. Another study found that ribavirin potentiated the antiviral effect of acyclovir.Some interest has been seen in its possible use as a treatment for cancers, especially acute myeloid leukemia.
Note that two natural products were already known with this imidazole riboside structure: substitution at the 5 carbon with OH results in pyrazofurin, an antibiotic with antiviral properties but unacceptable toxicity, and replacement with an amino group results in the natural purine synthetic precursor 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR), which has only modest antiviral properties. Taribavirin
The most successful ribavirin derivative to date is the 3-carboxamidine derivative of the parent 3-carboxamide, first reported in 1973 by J. T. Witkowski et al., and now called taribavirin (former names "viramidine" and "ribamidine"). This drug shows a similar spectrum of antiviral activity to ribavirin, which is not surprising as it is now known to be a pro-drug for ribavirin. Taribavirin, however, has useful properties of less erythrocyte-trapping and better liver-targeting than ribavirin. The first property is due to taribavirins basic amidine group which inhibits drug entry into RBCs, and the second property is probably due to increased concentration of the enzymes which convert amidine to amide in liver tissue. Taribavirin completed phase III human trials in 2012. References
External links
"Ribavirin". Drug Information Portal. U.S. National Library of Medicine.