According to a large observational study published Friday in the medical journal The Lancet, seriously ill COVID-19 patients who were treated with hydroxychloroquine and chloroquine were more likely to lose their lives or develop heart arrhythmias.
Researchers gathered data from more than 96,000 patients with confirmed COVID-19 from around 670 hospitals. These patients were hospitalized from late December to mid-April, and either died or been discharged by April 21st.
Almost 15,000 patients were treated with hydroxychloroquine or chloroquine, or one of those drugs combined with an antibiotic.
About 1 in 11 patients in the control group died in the hospital. About 1 in 6 patients treated with chloroquine or hydroxychloroquine alone died in the hospital. About 1 in 5 who took chloroquine and an antibiotic died and almost 1 in 4 treated with hydroxychloroquine and an antibiotic died.
Researchers also concluded that cardiac arrhythmias were common among patients who received any of the four treatments. The largest increase was among the group treated with hydroxychloroquine and an antibiotic; 8% of those patients developed a heart arrhythmia, compared with 0.3% of patients in the control group.
Study co-author Dr. Frank Ruschitzka, director of the Heart Center at University Hospital Zurich, said: “Previous small-scale studies have failed to identify robust evidence of a benefit and larger, randomized controlled trials are not yet completed.” “However, we now know from our study that the chance that these medications improve outcomes in COVID-19 is quite low.”