Hydroxychloroquine, the drug President Donald Trump has promoted as a potential cure for the coronavirus, has been linked to a higher risk of death in COVID-19 patients, according to a study in the medical journal The Lancet.
The study looked at patients who had been treated with hydroxychloroquine, originally an antimalarial drug, as well as the related drug chloroquine.
Researchers found that those treated with hydroxychloroquine or chloroquine were more likely to die than those being given other treatments, even when factors like age, sex, and underlying conditions were accounted for.
Around 9% of the patients not treated with hydroxychloroquine or chloroquine died, while the numbers were as high as 18%, 24%, and 22% of patients dying when taking various combinations of hydroxychloroquine or chloroquine-based treatments, the study found.
“Regimens of chloroquine or hydroxychloroquine … are not useful and could be harmful in hospitalized patients with COVID-19,” other researchers wrote in comments to The Lancet about the study.
Hydroxychloroquine and chloroquine treatments seem to leave patients more at risk for a type of heart irregularity called de-novo ventricular arrhythmia, which can cause fatal heart problems. This could be the cause of the higher numbers of deaths, although the researchers say that they would need to perform more work before they could be sure exactly how and why the drugs are leading to deaths.
The new paper, authored by researchers from Harvard Medical School, University Hospital Zurich, and the University of Utah, stated that “hydroxychloroquine or chloroquine … are being widely used for treatment of COVID-19, despite no conclusive evidence of their benefit” and warned that the safety of these treatments had been poorly studied.
The new study looked at data from 671 hospitals around the world, comparing the outcomes of 96,000 coronavirus patients who were treated with hydroxychloroquine, chloroquine, or another treatment.
Experts are skeptical that the drugs will be a miracle cure for the virus, and the FDA has explicitly warned the public not to take the drugs without medical supervision due to their potential dangers. But Trump has touted the drug as a breakthrough and recently claimed he had been taking the medicine as a preventative measure despite not being diagnosed with the coronavirus.
There is no scientific evidence that hydroxychloroquine can prevent the disease.
The Lancet study was an observational study, not a double-blind randomized control trial — the gold standard of drug trials. While the study shows that the use of the drugs and higher death rates are correlated, it can’t prove that the higher death rates are directly caused by the drugs.
However, since the study looked at such a large number of patients, the results back up concerns about the potential dangers of the drug.