Antimalarial use and arrhythmias in COVID-19 and rheumatic patients: A matter of dose and inflammation?

We read with great interest the paper by Graef and colleagues, ‘Festina lente: hydroxychloroquine, covid-19 and the role of the rheumatologist’.1 As the authors correctly point out, despite firm evidence that their efficacy and safety are lacking,2 antimalarials are being widely prescribed for the treatment of patients with COVID-19. This, as also underlined with some concern by the European League Against Rheumatism President Iain McInness,3 has rapidly led to antimalarial supply shortages worldwide, primarily affecting patients with rheumatic disease, such as those with systemic lupus erythematosus and rheumatoid arthritis (RA). In these groups, low-dose antimalarials (hydroxychloroquine up to 6 mg/kg/day and chloroquine up to 4 mg/kg/day) are the mainstay to control immunological response and to prevent flare in view of their favourable efficacy and safety profile.