Macrolides and Heart Attacks

Cardiovascular problems and antibiotic connection in COPD and pneumonia patients

(RxWiki News) We think of antibiotics as something that will only bring us health – not harm. However a recent study is exploring a potential connection between a specific antibiotic and heart troubles.

For patients coping with infections of the lower respiratory tract, a certain type of antibiotic, called macrolides, often in the form of a specific medication, clarithromycin, is frequently prescribed.

In patients using these medications, researchers found a possible link to cardiovascular events in the long-term, including issues such as arrhythmia, heart failure and sudden cardiac death. 

However, the authors of this study take care to stress that more research needs to be completed to confirm these findings.

"Learn breathing exercises to help with COPD symptoms."

Led by Stuart Schembri, MD, of the Ninewells Hospital in Dundee, UK, researchers looked at patients coping with an abrupt worsening of their chronic obstructive pulmonary disease (COPD) symptoms (known as an acute exacerbation) and patients with community-acquired pneumonia.

The study used data from two large datasets. The EXODUS (Exacerbations of Obstructive Lung Disease managed in UK Secondary care) study gathered information on 1,343 COPD patients from 12 UK hospitals between 2009 and 2011.

The researchers then looked at national death certification data to find instances of death and when cardiovascular-related causes were involved.

The Edinburgh pneumonia cohort involved 1,631 community-acquired pneumonia patients at one Edinburgh hospital between 2005 and 2009. Instances of cardiovascular-related deaths were determined by reviewing patients’ case notes.

For both datasets, patients who used clarithromycin while in the hospital were compared with those who did not. Within one year, 268 of all the COPD patients and 171 of the pneumonia patients had returned to the hospital due to a heart issue. 

After one year, 26 percent of the COPD patients prescribed clarithromycin experienced at least one cardiovascular event (73 out of 281 patients). This was compared to 18.4 percent of COPD patients who did not use the medicine (195 out of 1,062 patients).

In pneumonia patients prescribed clarithromycin, 12.6 percent were admitted to the hospital for at least one cardiovascular event (123 out of 980 patients), while the same was true for 7.4 percent of pneumonia patients not given the medicine (48 out of 651 patients).

This study differed from previous studies connecting heart problems and macrolides in that it did not focus only on patients with pre-existing risks for cardiovascular problems, and it looked beyond only the time when clarithromycin was being used.

“Evidence is accumulating for long term cardiovascular risks associated with macrolides. The role of antibiotics in exacerbations of chronic obstructive pulmonary disease is controversial, and no evidence from controlled trials suggests that macrolides are superior to the alternatives in this situation,” report the researchers.

However, they do report that macrolide use in pneumonia cases is more complicated, writing, “A large body of evidence suggests that short term mortality is reduced in patients receiving macrolides for severe community acquired pneumonia.”

Therefore, the benefits versus the risks still need to be explored in greater depth. The researchers take care to note that “Our findings require validation in independent datasets, especially from primary care settings and through randomized controlled trials of macrolides with long term follow-up.”

The study was published in March 2013 by the British Medical Journal.  No conflicts of interest were reported.

Review Date: 
March 23, 2013