EU regulators warn over safety of Trump's favourite COVID drugs

As the search for therapies for COVID-19 continues, European regulators have urged caution over the cardiac side-effects of chloroquine and its close relative hydroxychloroquine.

The European Medicines Agency issued a statement that the drugs are known to potentially cause heart rhythm problems, which could be made worse when combined with other drugs such as the antibiotic azithromycin that have similar effects on the heart.

Already things are not looking good for the drugs formerly touted by the Trump administration as a potential cure for COVID-19 – and the EMA added to the doubts over the drugs after noticing trial results showing elevated risks of heart trouble associated with them.

Even Trump has begun to turn his back on the drugs after a large coronavirus trial in the US showed no benefit and more deaths in those taking hydroxychloroquine than standard care, according to the Guardian.

The EMA was troubled by two trials, one in COVID-19 patients in Brazil taking chloroquine and another international study of rheumatoid arthritis patients taking hydroxychloroquine.

Findings showed serious and in some cases fatal heart rhythm problems, particularly at high doses or in combination with azithromycin.

This combination was backed by the author of the small and inconclusive French study that began the furore over the drugs.

Although trials of the drugs are ongoing in COVID-19, the EMA pointed out that data so far is “limited and inconclusive” and any clinical benefits have yet to be shown.

What’s also worrying the EMA is that some clinical trials in COVID-19 are using higher doses than those recommended in authorised indications such as malaria and rheumatoid arthritis.

Side effects can occur at recommended doses and the risk increases with the dose, including abnormal electrical activity that affects heart rhythm – QT prolongation to be specific.

The EMA recommends that those conducting ongoing trials should consider the possibility of the side effects, particularly at higher doses, and be even more cautious when combining chloroquine or hydroxychloroquine with other drugs such as azithromycin.

Along with the EMA, Europe’s network of national regulators are “monitoring the situation closely” and have enhanced safety monitoring of medicines used to treat COVID-19 “in order to take timely action when necessary”.