Doctors first became interested in famotidine after hearing reports that people in China who took the drug for heartburn were surviving COVID-19, while other people who essentially had the same risk factors but were taking different heartburn drugs like cimetidine or omeprazole (sold in the US as Tagamet and Prilosec, respectively) were dying from the disease. Perhaps famotidine was somehow bolstering these patients and improving their chances for survival…

Shortly afterward, on May 8, a team, led by Columbia University doctors Daniel Freedberg and Julian Abrams, posted a study on the preprint server medRxiv that compared the outcomes of people with COVID-19 who were prescribed famotidine within 24 hours of being admitted to the hospital to those who didn’t get the heartburn drug. They looked at the records of more than 1,600 patients at Columbia University Irving Medical Center between late February and mid-April. Of those, 84 patients received 10–40 mg of intravenous famotidine daily over the course of about 6 days…

Meanwhile, in early June, the journal Gut published a small case series of 10 people who developed COVID-19 and reported taking famotidine during their illness (2020, DOI: 10.1136/gutjnl-2020-321852). These people were not sick enough to go to the hospital, but their symptoms, such as cough and shortness of breath, improved within a day or two of taking the heartburn drug. It’s a small study, and the researchers acknowledge that it’s not enough to establish there’s any real benefit from taking famotidine for people who have COVID-19. Those authors recommend a clinical trial with famotidine be carried out with patients with milder disease in addition to the trial going on at Northwell hospitals.