Thursday, May 17, 2012

NEJM: Cardiovascular Risks Of Taking Azithromycin

 

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# 6331

 

 

Although it isn’t always fully appreciated, one of the `truths’ about medicine is that all drugs carry with them some risk of side effects. There is simply no such thing as a 100% safe and totally benign drug.

 

Often, adverse effects are so rare as to not show up during a drug’s clinical trials, and only become apparent after the drug has been in wide use for years.

 

It is axiomatic that anytime you take a drug, you must weigh its likely benefits against any potential health risks it may introduce. 

 

Today the NEJM has an article about the potential cardiovascular risks of taking one of the world’s most popular antibiotics; azithromycin

 

`Zith’ is a macrolide antibiotic chemically similar to erythromycin that is effective against a wide variety of bacteria. It is commonly used for middle ear infections, bronchitis, pneumonia, sinusitis and several sexually transmitted infections.

 

While generally well tolerated (and effective), known side effects include gastrointestinal difficulties (nausea, vomiting, diarrhea)  among less than 5% of those taking the drug, and more rarely, abnormal liver tests, allergic reactions, and nervousness.

 

Although some antibiotics are known to cause potentially dangerous cardiac arrhythmias, up until now `Zith’  has not been counted among them. 

 

Today’s study in the NEJM finds a small absolute increase in cardiovascular deaths during a 5-day treatment course with azithromycin compared to taking no antibiotics or with taking amoxicillin, particularly among those with cardiac risk factors.

 

Azithromycin and the Risk of Cardiovascular Death

Wayne A. Ray, Ph.D., Katherine T. Murray, M.D., Kathi Hall, B.S., Patrick G. Arbogast, Ph.D., and C. Michael Stein, M.B., Ch.B.

N Engl J Med 2012; 366:1881-1890 May 17, 2012

 

Conclusions

During 5 days of azithromycin therapy, there was a small absolute increase in cardiovascular deaths, which was most pronounced among patients with a high baseline risk of cardiovascular disease.

Before anyone starts pitching their Z-packs down the loo, the actual number of cardiovascular incidents was relatively small. And this study was a retrospective analysis of Tennessee Medicaid records between 1992 and 2006 – not a randomized control trial (RCT) - and therefore subject to a number of limitations.

 

Since the full study is behind a pay wall, for more on all of this we turn to coverage from MedPage Today:

 

Azithromycin May Up Risk of Cardiac Death

By Nancy Walsh, Staff Writer, MedPage Today

Published: May 16, 2012

Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston.

Action Points

  • Explain that a Medicaid database study found an increased risk for cardiovascular death, sudden death, and overall all-cause mortality associated with a 5-day course of azithromycin.
  • Note that the same findings were not true for amoxicillin or ciprofloxacin compared with controls taking no antibiotics, but there were excess deaths associated with levofloxacin.

Use of a common antibiotic, azithromycin, appears to significantly increase the risk of sudden cardiac death when compared with no antibiotic treatment, according to analysis of data from Medicaid patients.

(Continue . . . )

 

None of this makes azithromycin a `bad medicine’, but it does highlight the need to recognize and balance the risks of taking this (or any other) drug with its likely benefits. 

 

And for some patients with elevated cardiac risk factors, it may be prudent for their doctors to now consider other antibiotic treatments.

 

Although antibiotics can often be lifesaving, evidence continues to mount that their use is less benign that previously thought.

 

The CDC reports that 50% of antibiotic use in hospitals is ` unnecessary or inappropriate’, and better antibiotic stewardship is needed if we are to combat the growing threat of antibiotic resistance.

 

You’ll find the CDC maintains an excellent GET SMART ABOUT ANTIBIOTICS webpage, which provides information on the prudent use of antibiotics.

 

And for more on the potential dangers of antibiotic use (and misuse) you may wish to revisit:

 

The Other Reason Not To Abuse Antibiotics
Get Smart About Antibiotics Week
ECDC/EMEA: Joint Report On Resistant Bacteria