Chloroquine and hydroxychloroquine are known to potentially cause heart rhythm problems, and these could be exacerbated if treatment is combined with other medicines, such as the antibiotic azithromycin, that have similar effects on the heart.

Recent studies have reported serious, in some cases fatal, heart rhythm problems with chloroquine or hydroxychloroquine, particularly when taken at high doses or in combination with the antibiotic azithromycin.

These medicines are being used in the context of the ongoing pandemic for treating patients with COVID-19 and investigated in clinical trials. However, clinical data are still very limited and inconclusive, and the beneficial effects of these medicines in COVID-19 have not been demonstrated. Results from large, well-designed studies are needed to make any conclusions.

Healthcare professionals are recommended to closely monitor patients with COVID-19 receiving chloroquine or hydroxychloroquine and to take into account pre-existing heart problems that can make patients more prone to heart rhythm issues. They should carefully consider the possibility of side effects, particularly with higher doses, and exercise extra caution when combining treatment with other medicines such as azithromycin that may cause similar side effects on the heart.

The full article can be accessed on the European Medicines Agency website by clicking here.