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. This network study was led by the Observational Health Data Sciences and Informatics community. OHDSI has established an international network of researchers and observational health databases with a central coordinating centre housed at the department of biomedical informatics at Columbia University.
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% increased rate of angina/chest pain and heart failure.
This study has already made significant impacts in the healthcare community. On 23 April, 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 (<30 days) safety profile did not identify excess risk in any of 16 severe adverse events as compared to a similar RA drug, sulfasalazine (SSZ). Long-term HCQ therapy was associated with a 65% increase in cardiovascular mortality as compared to SSZ.
"Hydroxychloroquine, both alone and in combination with azithromycin, gained strong consideration as a potential COVID treatment without a large-scale study of its overall safety profile," said Dr Daniel Prieto-Alhambra, co-senior author on this study. "We had access to an unprecedented amount of data on this drug, and we were relieved to find no worrying side effects in the short-term use of hydroxychloroquine. However, when prescribed in combination with azithromycin, it may induce heart failure and cardiovascular mortality and we would urge caution in using the two together."
This study examined more than 950,000 HCQ users through deidentified electronic health records and administrative claims data over a 20-year period. Records were collected from 14 different databases spanning six nations (Germany, Japan, Netherlands, Spain, the UK, US) and then mapped to the OMOP Common Data Model to generate this large-scale analysis.
"At medical school we were taught to 'first do no harm' and to me, our study focuses on this core belief of modern medicine," said Dr Jennifer Lane, who served as co-lead author on this study along with Jamie Weaver. "OHDSI has the power to investigate this question in a very thorough way and to go through rigorous steps. We are looking at patients from the general population, which is why it is so important to look at data from multiple countries. There are reasons why you may get bias from one data source, but if we find a signal in the Netherlands, and we find it in Spain, and we find it in the US, then we know we have something."
The study was developed and executed by the OHDSI (Observational Health Data Sciences and Informatics) community, a multi-stakeholder, interdisciplinary collaborative to bring out the value of health data through large-scale analytics. All solutions are open-source, and links to the study protocol, code and results are posted at the bottom of this release.
"It required a global effort to generate this level of reproducible, reliable real-world evidence to inform decision-making around COVID treatment," said Dr Patrick Ryan, co-senior author on this study. "Our community collaborated for years to develop the high-level analytics which set the course for these studies. Standardising data for nearly 1,000,000 patients on hydroxychloroquine provides confidence in these findings, and we are pleased to see that this study has already helped make a positive clinical impact as treatment options continue to be evaluated."
Background: Hydroxychloroquine, a drug commonly used in the treatment of rheumatoid arthritis, has received much negative publicity for adverse events associated with its authorisation for emergency use to treat patients with COVID-19 pneumonia. We studied the safety of hydroxychloroquine, alone and in combination with azithromycin, to determine the risk associated with its use in routine care in patients with rheumatoid arthritis.
Methods: In this multinational, retrospective study, new user cohort studies in patients with rheumatoid arthritis aged 18 years or older and initiating hydroxychloroquine were compared with those initiating sulfasalazine and followed up over 30 days, with 16 severe adverse events studied. Self-controlled case series were done to further establish safety in wider populations, and included all users of hydroxychloroquine regardless of rheumatoid arthritis status or indication. Separately, severe adverse events associated with hydroxychloroquine plus azithromycin (compared with hydroxychloroquine plus amoxicillin) were studied. Data comprised 14 sources of claims data or electronic medical records from Germany, Japan, the Netherlands, Spain, the UK, and the USA. Propensity score stratification and calibration using negative control outcomes were used to address confounding. Cox models were fitted to estimate calibrated hazard ratios (HRs) according to drug use. Estimates were pooled where the I2 value was less than 0·4.
Findings: The study included 956 374 users of hydroxychloroquine, 310 350 users of sulfasalazine, 323 122 users of hydroxychloroquine plus azithromycin, and 351 956 users of hydroxychloroquine plus amoxicillin. No excess risk of severe adverse events was identified when 30-day hydroxychloroquine and sulfasalazine use were compared. Self-controlled case series confirmed these findings. However, long-term use of hydroxychloroquine appeared to be associated with increased cardiovascular mortality (calibrated HR 1·65 [95% CI 1·12–2·44]). Addition of azithromycin appeared to be associated with an increased risk of 30-day cardiovascular mortality (calibrated HR 2·19 [95% CI 1·22–3·95]), chest pain or angina (1·15 [1·05–1·26]), and heart failure (1·22 [1·02–1·45]).
Interpretation: Hydroxychloroquine treatment appears to have no increased risk in the short term among patients with rheumatoid arthritis, but in the long term it appears to be associated with excess cardiovascular mortality. The addition of azithromycin increases the risk of heart failure and cardiovascular mortality even in the short term. We call for careful consideration of the benefit–risk trade-off when counselling those on hydroxychloroquine treatment.
Funding: National Institute for Health Research (NIHR) Oxford Biomedical Research Centre, NIHR Senior Research Fellowship programme, US National Institutes of Health, US Department of Veterans Affairs, Janssen Research and Development, IQVIA, Korea Health Industry Development Institute through the Ministry of Health and Welfare Republic of Korea, Versus Arthritis, UK Medical Research Council Doctoral Training Partnership, Foundation Alfonso Martin Escudero, Innovation Fund Denmark, Novo Nordisk Foundation, Singapore Ministry of Health's National Medical Research Council Open Fund Large Collaborative Grant, VINCI, Innovative Medicines Initiative 2 Joint Undertaking, EU's Horizon 2020 research and innovation programme, and European Federation of Pharmaceutical Industries and Associations.
Jennifer CE Lane, James Weaver, Kristin Kostka, Talita Duarte-Salles, Maria Tereza F Abrahao, Heba Alghoul, Osaid Alser, Thamir M Alshammari, Patricia Biedermann, Juan M Banda, Edward Burn, Paula Casajust, Mitchell M Conover, Aedin C Culhane, Alexander Davydov, Scott L DuVall, Dmitry Dymshyts, Sergio Fernandez-Bertolin, Kristina Fišter, Jill Hardin, Laura Hester, George Hripcsak, Benjamin Skov Kaas-Hansen, Seamus Kent, Sajan Khosla, Spyros Kolovos, Christophe G Lambert, Johan van der Lei, Kristine E Lynch, Rupa Makadia, Andrea V Margulis, Michael E Matheny, Paras Mehta, Daniel R Morales, Henry Morgan-Stewart, Mees Mosseveld, Danielle Newby, Fredrik Nyberg, Anna Ostropolets, Rae Woong Park, Albert Prats-Uribe, Gowtham A Rao, Christian Reich, Jenna Reps, Peter Rijnbeek, Selva Muthu Kumaran Sathappan, Martijn Schuemie, Sarah Seager, Anthony G Sena, Azza Shoaibi, Matthew Spotnitz, Marc A Suchard, Carmen O Torre, David Vizcaya, Haini Wen, Marcel de Wilde, Junqing Xie, Seng Chan You, Lin Zhang, Oleg Zhuk, Patrick Ryan, Daniel Prieto-Alhambra
[link url="https://www.sciencedaily.com/releases/2020/08/200825135245.htm#:~:text=Hydroxychloroquine%20plus%20azithromycin%20increases%20heart%20risk%2C%20finds%20global%20study,-Date%3A%20August%2025&text=Summary%3A,significant%20cardiovascular%20risks%2C%20including%20death."]Columbia University Irving Medical Centre material[/link]
[link url="https://www.thelancet.com/journals/lanrhe/article/PIIS2665-9913(20)30276-9/fulltext"]The Lancet Rheumatology abstract[/link]