brand logo

Am Fam Physician. 2004;70(2):367-368

Clinical Question: In patients who have experienced a myocardial infarction (MI), is antibiotic therapy aimed at eradicating Chlamydia pneumoniae infection effective in preventing a second coronary event?

Setting: Outpatient (any)

Study Design: Meta-analysis (randomized controlled trials)

Synopsis: The authors of this meta-analysis searched several databases to find English language, randomized controlled trials of antibiotic therapy directed against C. pneumoniae infection that evaluated a clinical outcome. Nine studies met their criteria, and more than 12,000 patients were enrolled.

All of the studies used a macrolide antibiotic as the primary intervention, with one study also using a triple therapy of azithromycin, metronidazole, and omeprazole to eradicate Helicobacter pylori infection. All patients had acute coronary syndrome or coronary heart disease and were not selected based on the presence of high C. pneumoniae titers. Duration of treatment ranged from three days to three months.

Overall, antibiotic treatment did not reduce the risk of experiencing any coronary event, MI, angina, or mortality. However, the investigators combined studies using a wide range of antibiotic dosages, including azithromycin for a total of five days, once-weekly azithromycin for three months, or clarithromycin or roxithromycin daily for 28 to 90 days. It is possible that higher dosages or longer treatment durations could produce a clinically relevant effect.

Bottom Line: Antibiotic therapy with a macrolide, aimed at eradicating C. pneumoniae infection, is ineffective at reducing the recurrence of a coronary event or decreasing mortality in patients who have had an MI or acute coronary syndrome. (Level of Evidence: 1a)

POEMs (patient-oriented evidence that matters) are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, see Copyright Wiley-Blackwell. Used with permission.

For definitions of levels of evidence used in POEMs, see

To subscribe to a free podcast of these and other POEMs that appear in AFP, search in iTunes for “POEM of the Week” or go to

This series is coordinated by Natasha J. Pyzocha, DO, contributing editor.

A collection of POEMs published in AFP is available at

Continue Reading

More in AFP

Copyright © 2004 by the American Academy of Family Physicians.

This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP.  See permissions for copyright questions and/or permission requests.