Here are the key points from the Medscape article summarizing an observational study which showed an increased risk of sudden cardiac death for patients on a five day course of Azithromycin compared to Amoxicillin or no antibiotics:
- May 17, 2012 issue of the New England Journal of Medicine.
- The patients were aged 30 to 74 with a mean age 49, and 77% were women.
- Compared with patients receiving amoxicillin therapy, during five days of azithromycin therapy, there were an estimated 47 additional cardiovascular deaths per one million courses of therapy. Among patients in the highest decile of cardiovascular risk score, there were an estimated 245 additional cardiovascular deaths per one million courses of azithromycin therapy.
- The risks of cardiovascular death were similar for ciprofloxacin and amoxicillin and for levofloxacin and azithromycin.
- “the azithromycin risk returns to baseline on days 6 to10”
- The study was supported by a grant from the National Heart, Lung, and Blood Institute and a cooperative agreement from the Agency for Healthcare Quality and Research Centers for Education and Research on Therapeutics.
I happen not to prescribe Azithromycin much, as I see it fail a lot as an antibiotic. I prefer the older macrolides as they work better in my experience. Having said that would I stop prescribing Azithromycin based on this? Unlikely, The increase in risk is very very low and is not clinically significant in my opinion.
The risk of dying from an untreated pneumonia (see risk calculator) especially in the elderly is greater irrespective of other co-morbidities. If aged 65y the risk is 0.6 to 0.7% and that is without any co-morbidities at all. Divide the 245 by 1000,000 i.e. a .0245 % increase in risk. Do you see much of a difference between 0.6% and 0.6245% ? I don’t see a clinically meaningful difference.