Antibiotic Zithromax and Arrhythmias - New Study

Posted today on Medpage Today:


FDA Warns of Arrhythmias with Azithromycin

By John Gever, Senior Editor, MedPage Today
Published: March 12, 2013


SILVER SPRING, Md. -- Patients with certain risk factors may be subject to life-threatening cardiac arrhythmias when taking azithromycin (Zithromax, Zmax), the FDA said Tuesday.

Existing QT prolongation, bradycardia, and low blood levels of magnesium or potassium are among the risk factors associated with the threat, according to an FDA drug safety communication posted on the agency's website.

In such patients, the drug may exacerbate QT prolongation and lead to torsades de pointes, a potentially lethal form of arrhythmia.

The warning resulted from a data review begun last year after researchers reported a higher risk of cardiovascular death in patients taking azithromycin versus amoxicillin or no antibiotics. Following the publication of that study in the New England Journal of Medicine last May, the FDA promised to investigate the findings.

In its Tuesday announcement, the FDA said it was strengthening the warnings-and-precautions section of the drug's label to highlight the risk of QT prolongation and torsades de pointes.

It indicated that, although the NEJM study had limitations, such as relying on death certificates for identifying a cardiovascular cause of death, "on balance ... the study was methodologically sound and supports the validity of the overall finding."

In the study, the risk of cardiovascular death was 1 in 4,100 among high-risk patients and the duration of increased risk corresponded to the duration of azithromycin exposure.

The FDA advised healthcare professionals to "consider the risk of fatal heart rhythms with azithromycin when considering treatment options for patients who are already at risk for cardiovascular events."

It also noted that some alternative antibiotics in the macrolide class (which includes azithromycin) as well as fluoroquinolones "also have the potential for QT prolongation or other significant side effects that should be considered when choosing an antibacterial drug."


Doreen

Doreen, is there a link to the article?

thanks,

lisa

lisa
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So much of medicine is looking solely down the wrong end of the gun barrel, and that is really a pity for all of us---Shannon

thanks for posting,yep I just saw the story on ABC News while riding the bike at the gym.........I will always believe that my taking the antibiotic Levaquin caused my afib in 2005.....I had a horrible reaction and for sure was depleted on K and Mag

To P

Yes, saw this on the news tonight. Makes me thankful to have gotten through the z-pak without incident I took some years ago.

Nancy

I have been prescribed zithromax many times [allergic to penicillin] for the bronchitis i get when "virus colds" go untreated. Works like a charm and i have never yet gotten any afib from it, knock on my head for wood. Of course i supplement heavily with potassium and magnesium, so that may explain it.
PeggyM

lisa s Wrote:
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> Doreen, is there a link to the article?
>
> thanks,
>
> lisa

Sorry Lisa,

I was away from the computer. Try this.

Doreen

[www.medpagetoday.com]

Thank you. Doreen.

lisa
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So much of medicine is looking solely down the wrong end of the gun barrel, and that is really a pity for all of us---Shannon

Interesting comment from the article (italics mine).

Existing QT prolongation, bradycardia, and low blood levels of magnesium or potassium are among the risk factors associated with the threat, according to an FDA drug safety communication posted on the agency's website.

And yet, most doctors will dismiss a potassium/magnesium connection.

I know about this first hand. Had bronchitis a few weeks ago. It was late in the evening and I had a very severe cough and temp of 102.5. Went to the walk-in clinic and the doctor gave me a Z Pac prescription. When I got home I read in the printout that, if you were taking Sotalol, you should not take this medication. I called back to the doctor and he said just to go ahead and take it, that lots of people who take Sotalol have taken it with no problem. I took the ordinary two doses as instructed. Ten minutes later, the nurse from the clinic called back and said they decided to err on the side of caution and not to take the Zithromax. Told her I already had and she said it wouldn't hurt me, but not to take any more and to get the new prescription filled. Within 30 hours I was in full-blown AFib--could hardly walk across the room. Had to go to the hospital to be cardioverted. Two days later I was in the hospital with both bronchitis and congestive heart failure. Still recuperating.