Swissmedic informs of the risk of serious adverse drug reactions from hydroxychloroquine and chloroquine


Medicinal products containing hydroxychloroquine are authorised in Switzerland for the treatment of certain autoimmune disorders and in malaria prophylaxis and therapy.

It is well known that both hydroxychloroquine and chloroquine can cause serious side-effects such as heart rhythm disturbances. These disturbances can increase if other medicines are taken at the same time, such as the antibiotic azithromycin. The active ingredients can also damage the liver, kidneys or nerves and lead to low blood sugar levels.

The initial findings from the treatment of coronavirus (COVID-19) patients show that hydroxychloroquine and chloroquine can cause serious heart rhythm disturbances which are sometimes fatal, particularly when used in high doses or in combination with the antibiotic azithromycin.

Both active substances are currently being used to treat COVID-19 patients in clinical trials. Swissmedic emphasises that there is little clinical data available as yet, and the efficacy of these active ingredients in patients with COVID-19 will not be proven until positive results from larger clinical trials are available.