Existing antiviral medicines
Timeline: Available now, but efficacy testing could take a month or more.

An existing, easy-to-produce medicine that proved effective at treating or preventing SARS-CoV-2 infection would provide the fastest relief for patients and doctors. The early hope is on hydroxychloroquine and chloroquine, and many hospitals, including the University of California, San Francisco, and the University of Washington, include them in their treatment guidelines. Some doctors are combining hydroxychloroquine with azithromycin, an antibiotic. Much of the published evidence comes from a very small French study and reports from China. Larger, more rigorous clinical trials are starting, but they will take time. Favipiravir, a flu drug shown in Japan, appeared beneficial in another small study. These medicines, especially the malaria drugs, which are being mass-produced, will be used by doctors on the front lines, but we will have to wait for evidence of whether they are benefitting patients and how much.

Remdesivir
Timeline: First data could come in April

Remdesivir, an antiviral medicine that failed as an Ebola treatment, was initially developed to work against a different coronavirus. There’s some evidence that it benefits Covid-19 patients. Its maker, Gilead, has been working with researchers and governments around the world to get clinical trials up and running. The company has said to expect results in April. Six large studies are in progress, with the first, in severely ill patients in China, due to finish as early as April 3, according to a government website. A study in patients with milder disease will also finish in April, with two more due in May. In the meantime, Gilead has made the drug available to hundreds of patients on a compassionate use basis. However, it recently said that, due to overwhelming demand, it would suspend access to the drug for all but pregnant women and children as it works to create a more systematic way of giving it out without interfering with clinical trials. This new system should be in place soon. Remdesivir must be given intravenously.