By ELIZABETH COONEY

Before Wednesday’s hopeful news about the experimental antiviral remdesivir broke, doctors treating patients hospitalized for Covid-19 were already hearing from a few families desperate to get the drug for their loved ones. Now they expect to hear more pleas in the days to come, even though the data are preliminary, results are not available for clinicians to evaluate, and the drug is not yet approved for emergency use.

“Obviously, anything positive with regard to treatment is encouraging,” said Todd Sarge, medical director of the surgical intensive care unit at Beth Israel Deaconess Medical Center in Boston. “What concerns me has been these things get very much hyped up in the news, and [patients’ families] will definitely be requesting it more often. And that can be a difficult conversation between families and our clinicians because for one, it’s still experimental, and two, it’s not widely available yet.”

Wednesday’s news came from a study led by the National Institute of Allergy and Infectious Diseases. In the double-blind, randomized controlled trial of 800 people, hospitalized Covid-19 patients who received the drug recovered in 11 days versus 15 days for patients who got a placebo. That design is considered the gold standard because no one knows who is or isn’t getting the drug, minimizing the chance of bias in judging outcomes.

Still, doctors on the frontlines are sounding notes of caution and asking questions while they lead trials themselves.

“It’s not a magic bullet. It’s not a drug that’s a quick answer to the epidemic, but it’s a step in the right direction,” said Otto Yang, a professor of medicine at the David Geffen School of Medicine at UCLA who is leading an NIAID remdesivir trial at the UCLA study site. “These were seriously ill patients. One question I have is will it work better in patients that are not so ill? Will it work as prevention? These are really key questions.”

Constance Benson, professor of medicine at the University of California, San Diego, School of Medicine and co-leader of an NIAID clinical trial there, is expecting to hear from patients.