Macroloid Antibiotics and Long Q Syndrome

I am a 41 year old female with a "healthy heart" who has  had PVCs, sometimes very bad bouts of them, for over twenty years now.

Recently I was put on a course of antibiotics for recurring Lyme Disease , a combination of Ceftin and Zithromax which I was told might be more effective in getting rid of the Lyme once and for all. Before the doctor prescribed the Zithromax however, he did an EKG. Naturally, having suffered with anxiety for so long over my heart palpitations I became a little alarmed and asked why he was doing an EKG. He told me that this class of antibiotics can sometimes cause Long Q Syndrome, but that personally he had never seen it. My EKG was totally normal.

I went home and looked up "Long Q Syndrome" and from what I read it is a possible occurance when taking certain drugs like Zithromax, even in people without prior Long Q, especially women. I have been very nervous about taking this medication, especially since I may be on it for a couple of months. I feel like I did not get adequate reassurance from my doctor or the internet to quell my fears and now everytime I get pvcs I fear it might turn into a dangerous arrhythmia which I understand Long Q can trigger.

What are the chances of me developing Long Q Syndrome from taking Zithromax?

If Long Q does occur from taking this drug, does dangerous arrhythmias only occur if the Long Q is left untreated for a long time,  or can it happen right away?

If Long Q does occur, can it be corrected?

Thank you for yor reply!

[CCF-M.D.-MJM]

Hello,

Long QT syndrome is a relatively rare syndrome.  It is true that people can have a normal QTc on their EKG and still have "long QT syndrome" but his is very rare.  Your chances of developing long QT syndrome from taking azithromycin is VERY rare. This would be different if you told me that you had a family history of sudden cardiac death, long QT syndrome, or syncope with a longish QT on EKG.  The FDA in the US is very strict.  If people were dying from this medication, it would be pulled from the market.  Many times the problem with QT prolonging medications is that they are on more than one at a time and the combination causes problems -- it sounds like this does not apply to you.

If the medication prolongs your QT interval, it should be stopped.  The immediate effect of the medication will resolve after the medication is metabolized, but it would mean that you could be at risk from other medications in the future.  This does not sound like it applies to you though.


If Long Q does occur, can it be corrected?

Long QT syndrome and its variants are a very complicated, often multifactorial problem.  If you have a genetic predisposition to long QT, that cannot be corrected.  Avoiding agents that prolong QT is a must.  There is no way to change the genetic make up, but risks can be decreased with mediation avoidance and ICD therapy if indicated.

Please be careful what you read on the internet.  There is a lot of scary, half true information and even true information that can be misinterpreted without knowing all the back ground.  For physicians and patients both, the internet is a great resource, but I am noticing increasing number of patients that are misinformed from internet sources.  This can have profound effects on their degree of anxiety and quality life.  Unfortunately most people don't even have the condition they are worried about and yet it paralyzes them with fear.

Thanks for posting and good luck.