Warnings

It is not advised to take azithromycin for a long time. Long-term use can cause the development of harmful microorganisms that are azithromycin resistant. Take azithromycin for the amount of time recommended by your physician.

Diarrhea brought on by Clostridium difficile: The "good" bacteria in the colon can be killed by azithromycin and other antibiotics, which promotes the growth of C. difficile bacteria. The "bad" bacteria C. difficile can lead to diarrhea.

Myasthenia gravis is a muscular condition whose symptoms can be made worse by azithromycin. Azithromycin may also result in muscular weakness. If you have a history of myasthenia gravis or notice any new muscle weakness, tell your doctor very away.

Azithromycin can alter the electrical activity of the heart in ways that are inappropriate and may result in potentially fatal irregular heart rhythms. If you have a history of any of the following, let your doctor know:

• existing QT prolongation heart rhythm issues
• low potassium or magnesium levels
• slower-than-normal heart rate
• the use of medications to treat arrhythmias or irregular heart rhythms