A new study in the BMJ suggests that the antibiotic clarithromycin may increase some patients’ risk of dying from heart-related causes.
Clarithromycin is prescribed for millions of people each year, HealthDay reports. The Danish research group that conducted the study said their findings require confirmation. Clarithromycin and the antibiotic roxithromycin are drugs in the group of antibiotics called macrolides. The researchers believe that macrolides increase the risk of potentially deadly heart rhythm problems in some patients. The study was published online in the BMJ on August 19.
The researchers, led by Henrik Svanstrom of the Statens Serum Institut in Copenhagen, analyzed more than 5 million courses of antibiotic treatment for Danish adults, 40 to 74, between 1997 and 2011. The patients took clarithromycin, roxithromycin, or penicillin V. There were 285 cardiac deaths during this period – 18 during the use of clarithromycin and 32 during the use of roxithromycin, according to HealthDay. After adjusting for other factors, the researchers concluded that ongoing use of clarithromycin was associated with a 76 percent higher risk of cardiac death, compared with the use of penicillin V. The absolute risk difference was 37 cardiac deaths per 1 million courses with clarithromycin. They found no heightened risk of cardiac death after clarithromycin treatment stopped, and roxithromycin use was not associated with increased risk of cardiac death.
Svanstrom said this study is “the first large-scale population-based observational study to show significantly increased cardiac risk with clarithromycin and the relative cardiac safety of roxithromycin,” according to HealthDay. Although any individual patient’s risk is small, Dr. Ambreen Khalil, an infectious disease specialist at New York’s Staten Island University Hospital said, “Patients with underlying heart conditions who are taking medications that affect the heart rhythm may be particularly vulnerable.”