Jthree years after the start of the COVID-19 pandemic, with millions of people around the world suffer from long-term complications of the virus, there is still no proven way to treat or prevent Long COVID, other than not getting infected in the first place.
Recently, however, there has been reason for cautious optimism. Researchers have found promising (albeit preliminary) signs that certain drugs may reduce the risk of developing long COVID, and possibly even lessen symptoms in people who are already sick.
The latest hopeful news is about metformin, an accessible and affordable drug approved by the United States Food and Drug Administration (FDA) to treat type 2 diabetes since the 1990s. Metformin, which belongs to a class of drugs called biguanides, is taken as a liquid or pill and works by controlling the amount of sugar in the blood. This too decreases inflammation in the body.
In a study which was published online in March but has not yet been peer-reviewed, researchers followed a group of 564 overweight or obese American adults who started a two-week course of metformin when they had a Acute COVID-19. People taking metformin were 42% less likely to be diagnosed with Long COVID in the following 10 months, compared to those taking a placebo when they first fell ill with COVID- 19. (The study also tracked the effects of the drugs ivermectin and fluvoxamine, but neither showed benefit against Long COVID.)
Metformin seems to be even more effective when used early. Among people who took it within four days of symptom onset, the risk of Long COVID fell by more than 60%. In total, about 6% of people who took metformin went on to be diagnosed with Long COVID, compared to more than 10% of people who took a placebo.
Other studies have shown that metformin can prevent the SARS-CoV-2 virus from replicating, which can help prevent both serious illness and long-term complications, says study co-author Dr. Carolyn Bramante, assistant professor at the University of Minnesota Medical School. Metformin appears to work against the virus by blocking a protein in human cells that the virus uses to copy itself, and disrupting the inflammatory response caused by the virus, she says.
Bramante says she was pleasantly surprised by how metformin seemed to prevent Long COVID, especially when taken immediately, although more research is needed to confirm the results. “It’s probably in every pharmacy in the world,” Bramante says. Someone could probably “get metformin within a day of finding out they have COVID.”
Going forward, Bramante says, researchers should also investigate whether metformin can treat existing Long COVID symptoms. Some experts believe that Long COVID is caused by remnants of the virus lingering in the body. If that’s true, Bramante says, the antiviral properties of metformin might help eliminate it from the body.
Other recent studies have also suggested that Paxlovid, an antiviral drug used to prevent severe cases of COVID-19 in high-risk patients, may help prevent long COVID in the same way. A study, which was put online at the end of 2022 but had not been peer-reviewed, found that people who took Paxlovid within five days of testing positive for COVID-19 had a 26% lower risk of developing long COVID to that of an untreated control group. (Ensitrelvir, another antiviral drug licensed in Japan but not the United States, may also reduce the risk of developing long COVID when taken soon after a positive test, its manufacturer announced in February.)
Some researchers are also studying whether Paxlovid can treat long-lasting COVID symptoms– an important question, as there is still no proven cure for Long COVID.
Learn more: People are much less likely to have long COVID after Omicron, study finds
Long COVID is difficult to treat, at least in part because the disease takes many forms. One person may suffer from debilitating fatigue and brain fog while another may have gastrointestinal issues or nervous system dysfunction. Instead of trying to find a single drug that can treat all long COVID Over 200 potential symptomssome research teams focus on specific symptoms, or clusters of symptoms, in hopes of finding targeted therapies.
Some tools used to treat people with myalgic encephalomyelitis/chronic fatigue syndrome, a post-viral condition which shares key symptoms with Long COVID (including extreme fatigue and crashes after exertion), may also be effective for people with post-COVID complications, according to an article Posted in Nature Reviews Microbiology in January. These tools include an energy rationing system strategy known as pacing, the low-dose anti-inflammatory naltrexone, and beta-blockers to slow heart rate and lower blood pressure. Antihistamines were also shown in small studies to reduce some symptoms of Long COVID, including fatigue, brain fog, and an inability to exercise, as did anticoagulant drugs.
Dr. Eric Topol, founder of the Scripps Research Translational Institute and co-author of the recent review, says he is also encouraged by preliminary data on stimulation of the vagus nerve, which helps control unconscious actions like breathing and heart rate, to relieve certain symptoms.
Several research teams are also investigating transcranial direct current stimulation (tDCS) as a potential treatment. Researchers have previously studied whether tDCS devices, which deliver low-level electrical currents to the scalp to stimulate the brain, can improve cognition, mental health and chronic pain. Consumers can purchase a variety of tDCS devices to use at home, although many have not been cleared by the FDA.
In a small study that was uploaded in September 2022 but not peer-reviewed, researchers found that after eight tDCS sessions, people with Long COVID reported reductions in physical fatigue and depression, although mental fatigue and overall quality of life scores did not improve.
Clinical neurologist and study co-author Dr Jordi Matias-Guiu said he plans a longer follow-up study, with patients receiving treatments for three weeks, to see if this leads to better outcomes. results. “This should be confirmed in other clinical trials, but the results are encouraging,” he says. “It’s a technique that could be administered at home, and it’s a non-invasive technique with minimal [side effects].”
The list of potential treatments is growing, but the field needs larger, better-coordinated research projects, Topol says; at the moment, most results come from small studies that need to be peer-reviewed, expanded, and replicated. RECOVER, the US National Institutes of Health’s billion-dollar Long COVID research project, has begun designing trials of potential treatments, but they have yet to turn into therapies.
The lack of proven treatments is disappointing, Topol says, but he views recent findings on metformin’s potential to prevent Long COVID as “very good news.”
Topol agrees that more studies of metformin are needed, but he says he thinks the early findings are promising enough and the drug is safe and cheap enough that he’ll take it personally now if he gets sick. of COVID-19. “I don’t want to have Long COVID,” Topol says.
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