CBC News (5/17/13) reports that Health Canada has announced both Zithromax and Zmax SR (both known generically as azithromycin) will have updated warnings to include the risk of possibly fatal cardiac problems. Health Canada noted that a study found a small increase in the risk of fatal heart events in patients who used azithromycin when compared to patients who took amoxicillin or who took no antibiotics.
The updated warning in Canada follows a similar warning in the US that Zithromax was associated with changes in the electrical activity of the patient’s heart. Those changes could result in a life-threatening heart rhythm.
A Danish study published in the New England Journal of Medicine (5/2/13), however, found no increase in the risk of death from heart problems in patients who used azithromycin compared with patients who used penicillin. The risk of death was greatly increased when patients who took azithromycin were compared with patients who took no antibiotic.
Azithromycin is an antibiotic that is used to treat bacterial infections, including pneumonia, urinary tract infections and skin infections. It has been linked in one study (found at the National Center for Biotechnology Information; 2006) to two cases of Stevens Johnson Syndrome, including a 62-year-old woman who took azithromycin for an upper respiratory tract infection and developed Stevens Johnson Syndrome.
READ MORE ZITHROMAX SJS LEGAL NEWS
In June 2012, the FDA sent a letter to Pfizer, maker of Zithromax, warning that the company must not downplay the risk of Stevens Johnson Syndrome in its marketing materials. Among the FDA’s concerns about the “1 Day. 1 Dose” brochure for Zmax (which is azithromycin extended-release medication) was that the brochure did not adequately address the severity of Stevens Johnson Syndrome.