The combination of hydroxychloroquine and azithromycin has been linked to significant cardiovascular risks, including mortality, in the largest safety study ever performed comparing hydroxychloroquine treatment to hydroxychloroquine and azithromycin treatment for rheumatoid arthritis patients.
Hydroxychloroquine is commonly used to treat rheumatoid arthritis, while azithromycin is a frequently-prescribed antibiotic to treat infections such as pneumonia, chest and sinus infections, etc. This network study, led by the Observational Health Data Sciences and Informatics (OHDSI) community, was recently published in Lancet Rheumatology.
In patients with rheumatoid arthritis, hydroxychloroquine treatment in the short term (30 days) was found to not carry excess risk of complications associated with its use, but hydroxychloroquine treatment in the long term had a 65% relative increase in cardiovascular-related mortality, compared to sulfasalazine, a similar rheumatoid arthritis drug.
Hydroxychloroquine and azithromycin together had a cardiovascular mortality risk that was more than twice (2.19) as high as the comparative treatment even in the short term based on findings from more than 320,000 users of that combination therapy. This treatment also produced a 15-20% increased rate of angina/chest pain and heart failure.