Hydroxychloroquine plus azithromycin increases heart risk, finds global study

The combination of hydroxychloroquine (HCQ) and azithromycin (AZM) has been linked to significant cardiovascular risks, including mortality, in the largest safety study ever performed on both HCQ and HCQ+AZM.

In patients with rheumatoid arthritis, HCQ treatment in the short term (30 days) was found to not carry excess risk of complications associated with its use, but HCQ treatment in the long term had a 65% relative increase in cardiovascular-related mortality, compared to sulfasalazine.

HCQ + AZM 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 percent increased rate of angina/chest pain and heart failure.

This study, first published on MedRxiv, has already made significant impacts in the healthcare community. On April 23, the European Medicines Agency (EMA) cited the study in a warning about the risk of serious side effects with chloroquine and hydroxychloroquine.

In July, the EMA again highlighted the study, among other efforts within the OHDSI community, in its eighth revision of The European Network of Centres for Pharmacoepidemiology and Pharmacovigilance (ENCePP) Guide on Methodological Standards in Pharmacoepidemiology.

This is the first published study to be generated from the OHDSI COVID Study-a-thon, a global effort in March to set the foundation for OHDSI efforts to design and execute network observational studies around characterization, patient-level prediction, and population-level effect estimation to inform decision-making around the global pandemic.

Multiple studies, several of which are highlighted later, have been posted to MedRxiv and are currently under peer review.

HCQ, a drug commonly used in the treatment of malaria, lupus and rheumatoid arthritis (RA), gained early attention during the pandemic as a potential COVID-19 treatment. The short-term (