Coronavirus Disease 2019 Treatment: A Review of Early and Emerging Options

McCreary, Erin K; Pogue, Jason M

Ribavirin, a guanosine analog that terminates RNA synthesis, was first approved in the 1980s and has been used clinically for respiratory syncytial virus, viral hemorrhagic fever, and in combination with interferon for hepatitis C. As mentioned previously (see LPV/r section), it was evaluated against SARS-CoV-1 in 2003 and used clinically in combination with corticosteroids and/or interferon in the absence of other treatment options; however, outcomes were either poor or ill-defined [54, 55] . The doses required for antiviral activity against SARS range from 1.2 to 2.4 grams by mouth every 8 hours, which are associated with excessive toxicity to patients [56] . Wang et al [3] evaluated the in vitro activity of ribavirin against SARS-CoV-2 and found an EC 50 of 109.5 µM, which was over 100 times less potent than remdesivir. The risk of hematologic toxicity at high doses likely outweighs potential clinical benefit, and therefore ribavirin was not considered a viable candidate for further investigation by the WHO research and development plan for SARS-CoV-2 given its lack of in vitro efficacy, toxicity profile, and poor outcomes.