Azithromycin, also known as Zithromax and Zmax SR, is a commonly prescribed antibiotic both in adults and children. It is used to treat a variety of bacterial infections including respiratory, throat, ear, sinus, skin as well as certain sexually transmitted infections such as Gonorrhea and Chlamydia. Health Canada, along with Pfizer Canada, issued a health alert to inform the public about the potentially lethal side effect of fatal heart arrhythmia. A study by Ray and al found during a 5 days course of treatment with azithromycin there was a small increased risk of cardiovascular death when compared to no antibiotic use as well as compared to amoxicillin.⁽¹⁾ This danger mainly affects those that are already at a higher risk for cardiovascular events such as those with arrhythmias and cardiac insufficiency. Those taking certain medications such as antiarrhythmics, antipsychotics, antidepressants and flouroquinolone antibiotics as well as those with low levels of potassium or magnesium are also at risk.

If you’re currently taking or recently finished a round azithromycin and have concerns make sure to speak to your healthcare provider.