Millions of people globally have the chronic condition long COVID.Credit: Nathan Posner/Anadolu Agency via Getty
Growing evidence suggests that a diabetes drug and one used to treat mild-to-moderate COVID-19 can prevent the infection from developing into long COVID, a chronic condition that affects millions of people worldwide. In response to promising clinical-trial results, some physicians say that they will start prescribing the medications, but others are not convinced by the latest evidence.
There is no universally agreed definition of long COVID, but it usually refers to symptoms that persist for more than three months after infection with the coronavirus SARS-CoV-2. The most common symptoms are fatigue, shortness of breath and cognitive impairment.
Observational studies have suggested that the antiviral Paxlovid1 and the diabetes drug metformin2 can reduce the risk of some long COVID symptoms. But until now, the drugs had not been tested in randomized, placebo-controlled trials in a broader group of participants — the gold standard for evaluating treatment efficacy.
“Having a good placebo-controlled trial makes my heart happy,” says David Smith, an infectious-disease physician at the University of California, San Diego.
Paxlovid shows promise
The Paxlovid trial involved 144 people who had SARS-CoV-2 and investigated their risk of developing long COVID after three months. The drug reduced that risk by 40%, compared with a placebo. The study was published on 16 July in The Lancet Infectious Diseases3.
“It’s a seminal paper,” says Timothy Henrich, an infectious-disease physician at the University of California, San Francisco. “If you reduce viral burden during those initial, critical few weeks of acute infection, you can reduce the long-term morbidity from infection,” he adds.
Smith says the findings are consistent with previous retrospective analyses1 that suggest Paxlovid can lower the risk of long COVID. He discusses these analyses with people he treats, who are often immunocompromised , when helping them to decide whether to take Paxlovid.
Myron Cohen, an infectious-disease physician at the University of North Carolina at Chapel Hill, says that unless people have a good reason for not wanting to use Paxlovid — such as taking immunosuppressive drugs that make it unsafe — he’s going to recommend it. “The risk of the drug itself is low,” he adds.
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