A coauthor of the study emphasized that it’s a small group of patients. Even so, he said he was “encouraged” by the results and now plans to do a larger study with outpatients on famotidine, the over-the-counter ingredient in Pepcid.
“We want to know, what’s the best way to address these patients, and keep them out of the hospital and get them feeling better sooner,” said Dr. Joseph Conigliaro, a physician at Northwell Health in New York and coauthor on the paper.
In the report, published Thursday in the medical journal Gut, all but one of the study subjects took the drug within 10 days of first experiencing symptoms such as cough and shortness of breath. The 10th patient took it 26 after symptoms began. They were between the ages of 23 and 71.
“All patients noticed a rapid improvement in their condition within 24 to 48 hours of starting famotidine,” according to the report. “These findings suggest that famotidine may affect the course of COVID-19.”
The researchers report they all felt nearly back to normal two weeks after taking the drug.
The report, called a case series, was written by doctors at Northwell and Cold Spring Harbor Laboratory in New York and other universities.
There’s interest in studying famotidine because it’s inexpensive and considered to be very safe, and one study has suggested the drug helps hospitalized Covid patients.
In the outpatient report, 7 of the 10 patients had no side effects. The other three experienced relatively minor side effects, nearly all of them known to be associated with famotidine, such as dizziness and gastrointestinal issues.
One patient — the only patient to describe worsening of any symptoms while taking the drug — described becoming more tired after taking famotidine.
When the 10 patients were struck by Covid in March and April, one of the study coauthors who knew the drug was being studied in hospitalized patients suggested they take famotidine.
“One of the authors decided to treat a family member and a few friends after learning more about the emerging famotidine trial because it has such a safe profile,” Conigliaro said. “He suggested they take famotidine and begin tracking their symptoms in a fastidious way.”
The report notes that the patients were enrolled in the study consecutively, meaning that the authors didn’t cherry-pick their study subjects and reject ones who got worse after taking the drug.
Three of the 10 patients took their temperatures and found they had a fever, which went down five to seven days after they started taking famotidine. One of those patients also monitored her blood oxygen levels at home, and found her levels improved while on the drug.
It’s possible that the famotidine actually did nothing, and the patients were just experiencing the natural healing process, perhaps along with what’s called the “placebo effect,” meaning that they perceived themselves as getting better because they were taking a pill, especially since it was recommended by the doctor.
That’s why the Northwell researchers are planning a double-blind clinical trial, where patients sick with Covid at home will be randomly assigned to take either famotidine or a placebo, and neither the patients nor the doctors will know who is taking which.
An earlier study by doctors at Northwell and Columbia University found that hospitalized Covid patients who were taking famotidine were more than twice as likely to survive the infection.
Those researchers are currently conducting a clinical trial on famotidine with hospitalized Covid patients.
They’d hoped to have preliminary results by mid-May, but the decreasing number of Covid patients in New York City slowed down the trial, Conigliaro said.
There have been no trials on whether famotidine works to prevent Covid infection, and Conigliaro advised that no one should take the drug to prevent or treat Covid without first consulting with a physician.
Interest in famotidine began when a Harvard infectious disease specialist, Dr. Michael Callahan, was working in China and noticed that some Covid patients were faring better than others. It turned out that these patients had heartburn and were low-income, which meant they were taking famotidine, which is less expensive than other reflux remedies.
At the same time, a group of scientists at Alchem Laboratories in Florida used a computer model to make a list of existing drugs that might fight coronavirus, and famotidine showed up near the top of the list.
It’s unclear why famotidine might work against Covid-19. It could have an antiviral effect, meaning it stops the virus from replicating. Or it might be because the drug reduces inflammation by blocking H2 receptors, which exist in both the stomach and the lungs.
