COVID-19 patients who took the diabetes drug metformin for two weeks after a diagnosis were less likely to develop long COVID-19 symptoms, according to results from a clinical trial.
The trial enrolled about a thousand participants who were symptomatic with a COVID-19 infection for less than a week. Participants were randomly selected to receive a placebo or one of three drugs: metformin, ivermectin or fluvoxamine.
About 6 percent of people who took metformin later developed long COVID-19, as determined by a medical diagnosis. In the placebo group, 10.6 percent of participants developed long COVID-19.
This meant that overall people who took metformin were 42 percent less likely to develop long COVID-19 compared to people who got the placebo.
The authors also note that the beneficial effect is potentially stronger for people who started taking metformin less than four days from symptom onset compared to people who started the medication four or more days after their first symptoms.
Metformin may help prevent long COVID-19 by reducing inflammation and oxidative stress or by suppressing production of the virus, according to laboratory studies.
The participants who received the two other drugs, ivermectin and fluvoxamine, did not see any benefits in terms of preventing long COVID-19.
A limitation of this trial is that it only included people who were ages 30 to 85 and who were overweight or obese. In addition, a larger clinical trial would be needed to gather more evidence on whether the benefits of taking the drug are consistent.