Anti-malarial drugs chloroquine and hydroxychloroquine should only be used to treat Covid-19 in clinical trials or in case of "national emergency", the European Medicine Agency (EMA) warned yesterday.
Around the world, countries are expanding access to the two compounds, which are used to treat malaria and are known to have anti-viral properties.
The medicines have shown early promise against the Covid-19 illness in early studies in France and China.
But the EMA cautioned that the drugs should not be used to treat Covid-19 cases unless absolutely necessary.
Both drugs have a number of potentially serious side effects, especially when taken in high doses or administered in tandem with other medications.