24 Jan Increased Short Term Risk of Adverse Cardiac Effects With Antibiotic Clarithromycin
MedicalResearch.com Interview with:
Professor Ian C K Wong
Fellow of Royal Pharmaceutical Society
Fellow of Royal College of Paediatrics and Child Health (Honorary)
Fellow of the Higher Education Academy
Chair in Pharmacy Practice
Head of Research Department of Practice and Policy
UCL School of Pharmacy
Medical Research: What is the background for this study? What are the main findings?
Dr. Wong: Previous studies had showed an increased cardiovascular risk associated with clarithromycin (a widely used antibiotic) but the duration of effect remained unclear. Therefore, we conducted this study to investigate the duration of cardiovascular adverse effect provided that the risk exists after patients receiving clarithromycin in Hong Kong. We used three study designs to examine the association (temporal relationship) between clarithromycin and cardiovascular adverse outcomes such as myocardial infarction, arrhythmia, stroke, cardiac mortality at different time points.
We found that there was an increased short-term risk of myocardial infarction, arrhythmia and cardiac mortality associated with clarithromycin in all study designs. However, no long-term risk was observed. In every 1000 patients, there was 1.90 extra myocardial infarction events in current use of CLARITHROMYCIN when compared with the use of amoxicillin.
Medical Research: What should clinicians and patients take away from your report?
Dr. Wong: Our study has clearly demonstrated a significant association between current exposure of clarithromycin and the risk of myocardial infarction, arrhythmia and cardiac mortality, providing important mechanistic insights to the previously observed cardiovascular mortality among patients on clarithromycin. Notwithstanding, the burning question is whether clinicians should avoid the use of clarithromycin altogether. The selection of antibiotics remains a balance between the antimicrobial efficacy and the risk of possible side effects including cardiovascular events. Albeit the high overall risks of myocardial infarction, arrhythmia and cardiac mortality conferred by clarithromycin, such risks are not homogeneous across our patient population. For instance, patients with older age, hypertension, and/or diabetes mellitus have a higher absolute risk for these cardiovascular outcomes. Thereby, caution should be exercised when selecting antibiotic for these high-risk individuals.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Wong: While avoidance of use among patients at high risk (patients with older age, hypertension, and/or diabetes mellitus) could be a possible way to reduce the excess cardiovascular risk associated with clarithromycin, it is recommended that future studies can also explore other interventions as clarithromycin is currently widely used for different indications in clinical setting.
Regarding research methods, we strongly encourage that future epidemiological studies can use several study designs to compare and validate their findings as different study designs have its own strengths and limitations.
Wong Angel Y S, Root Adrian, Douglas Ian J, ChuiCeline S L, Chan Esther W, Ghebremichael-Weldeselassie Yonas et al. Cardiovascular outcomes associated with use of clarithromycin: population based study BMJ 2016; 352 :h6926
Prof. Ian CK Wong (2016). Increased Short Term Risk of Adverse Cardiac Effects With Antibiotic Clarithromycin