The study found that the patients on whom the drug was applied had an increased risk of death or cardiac issue.
The findings, published yesterday in medical journal, The Lancet, surveyed 96,000 coronavirus patients across six continents.
It is regarded the biggest analysis yet of the use of antimalarial drugs to treat Covid-19.
The report showed that the risk of death was 34% higher in patients who received hydroxychloroquine.
They also had a 137% higher risk of developing heart arrhythmia.
The risks rose higher for patients who took hydroxychloroquine with an antibiotic:45% risk of death and 411% risk of arrhythmia.
Experts said yesterday that although The Lancet findings emerged only from an analysis of medical…