Experts say low-dose aspirin might be an underutilized weapon in our battle with the coronavirus
During the first months of the pandemic, back when vaccines were little more than a wishful ambition, the global medical community was desperate for something — anything — that could weaken the mortal grip of severe Covid-19 disease.
Aspirin emerged as an early drug-of-interest
Covid-19 does its damage primarily via blood clots and inflammation. Aspirin, despite being one of the world’s oldest and cheapest medicines, is a potent blood thinner and anti-inflammatory agent. It can also block clots from forming. It seemed worth a look.
The early findings were promising. One study in the U.S. found that hospitalized Covid-19 patients promptly treated with aspirin were much less likely to need mechanical ventilation or ICU care than those who did not get the drug. Aspirin administration also reduced the risk of death.
There’s reason to believe that aspirin — if taken early enough in the course of infection — could provide life-saving benefits.
When that study came out last October, I spoke with two of its authors. They were optimistic about aspirin’s potential but said more work was needed to back up their findings.
Some of the research that followed seemed to deflate the aspirin balloon. A meta-analysis published last January in the American Journal of Cardiology concluded that aspirin treatment does not reduce Covid-19 mortality. More recently, an NIH-sponsored clinical trial found no evidence that giving aspirin to Covid-19 patients led to better outcomes.
Despite these findings, there’s still reason to believe that aspirin — if taken early enough in the course of infection — could provide life-saving benefits.
The most compelling evidence comes from a group of researchers at the U.S. Department of Veterans Affairs (VA). For a study published earlier this year, the VA group examined health data collected from more than 35,000 people, many of whom were at increased risk for severe Covid-19 disease due to age and comorbidities.
About one in four people in the study were taking aspirin for medical reasons. (A daily low-dose aspirin is often prescribed for those at risk for heart trouble or stroke.) After controlling for variables that could skew their data, the VA team found that the risk of death due to Covid-19 decreased by more than 60% among aspirin users, compared to a matched group that did not take aspirin.
“When we first saw the data, we didn’t quite believe it,” says Thomas Osborne, MD, first author of the study and director of the VA’s National Centre for Collaborative Healthcare Innovation. The protective effects of aspirin were so robust that he and his co-authors took extra time to review their work and confirm their figures with outside experts. Everything held up. “We thought geez, this is a big deal,” Osborne says.
A highly respected journal, PLOS ONE, published his group’s findings in February. That same month, a similar study from Israel also found that people taking aspirin to prevent heart disease were protected from Covid-19. Osborne says he expected to see significant interest and follow-up work on aspirin. But so far that hasn’t happened. “I don’t understand it,” he says.
“It is amazing to me that aspirin isn’t a bigger part of the dialogue.”
He and I talked about some of the other aspirin research that has appeared this year, including the prominent NIH-funded clinical trial that failed to find evidence of a benefit. He says it’s possible that this trial discouraged interest in aspirin, but he doesn’t believe its findings clash with his own. That’s because, in the NIH-funded trial, people started taking aspirin relatively late in the course of the infection.
“Aspirin may work really well as a preventative, but it can’t dissolve a blood clot once it’s formed,” he explains. “So, I think the key to aspirin is taking it before you get really sick.”
Others share his view.
In an editorial published last June in the journal Expert Opinion on Investigational Drugs, three American clinicians argued that a daily low-dose aspirin, taken soon after infection, could help mitigate the blood clots, inflammation, and lung thrombosis that fuel both severe Covid-19 disease and also some aspects of long-Covid syndrome.
“Rapid deployment of early aspirin can potentially reduce the burden of disease for the patients and the health care system,” the authors of that editorial wrote.
I heard something similar last year when I spoke with Michael Mazzeffi, MD, an associate professor at the University of Maryland.
Mazzeffi contributed to some of the early and promising research on aspirin for Covid-19. “I do think taking aspirin once you’re ill is probably too late,” he told me. “It’s hard to know the optimal timing, but you probably want to be taking it early, before clots form.”
He stressed that aspirin can be risky for kids. But if you’re an adult and your doctor gives you the all clear, taking a daily low-dose aspirin (81 mg) for a few weeks might be a low-risk, high-reward move if you’ve tested positive or have been exposed to someone with Covid-19.
Osborne agrees that aspirin, which is an over-the-counter drug, has a good safety profile. But he stops short of saying that people should take it as a Covid-19 safeguard. “I think it can be dangerous to give out blanket recommendations,” he says. Instead, he hopes that his work will encourage the medical community to take a closer look at aspirin and its Covid-19 benefits.
“We found pretty dramatic positive effects,” he says. “It is amazing to me that aspirin isn’t a bigger part of the dialogue.”
