Canadian health authorities have issued a warning against the use of anti-malarial drugs chloroquine and hydroxychloroquine to treat coronavirus infections or prevent reinfections.
"Chloroquine and hydroxychloroquine can have serious side effects. These drugs should be used only under the supervision of a physician," Canada's public health agency said in a note posted Saturday on its website.
"Health Canada is concerned that some people may be directly buying and using chloroquine or hydroxychloroquine to prevent or treat COVID-19," it said, noting they can cause "serious heart rhythm problems."
The European Medicines Agency on Thursday issued a similar warning about the drugs, whose promise as a coronavirus treatment has been touted by US President Donald Trump.