Azithromycin - Uses, Side Effects, and More

What are the most common side effects of azithromycin?

The most common side effects of azithromycin are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

• Nausea and vomiting
• Diarrhea
• Stomach pain

There may be other side effects of azithromycin that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of azithromycin?

While less common, the most serious side effects of azithromycin are described below, along with what to do if they happen.

Severe Allergic Reactions. Azithromycin can cause allergic reactions, which can be serious. Stop using Azithromycin and get help right away if you have any of the following symptoms of a serious allergic reaction.

• Breathing problems or wheezing
• Racing heart
• Fever or general ill feeling
• Swollen lymph nodes
• Swelling of the face, lips, mouth, tongue, or throat
• Trouble swallowing or throat tightness
• Itching, skin rash, or pale red bumps on the skin called hives
• Nausea or vomiting
• Dizziness, feeling lightheaded, or fainting
• Stomach cramps
• Joint pain

Angioedema. Azithromycin may cause a certain type of allergic reaction called angioedema. The usual symptoms of this reaction include swelling of the lips, face, tongue, or throat. Stop using the medicine and call your healthcare provider if you have this type of swelling. If it is causing problems breathing, seek immediate medical attention.

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking azithromycin. Call your healthcare provider right away if you have any of the following symptoms of liver damage.

• Nausea or vomiting
• Stomach or belly pain
• Fever
• Weakness or unusual tiredness
• Itching
• Loss of appetite
• Light colored poop
• Dark colored urine
• Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Heart Rhythm Changes. Azithromycin may cause rare dangerous heart rhythm problems called QT prolongation and torsade de pointes. Some people have a higher risk of this, including people who are older, have other people in their family who have had these conditions, have low potassium or magnesium, or who take some medicines for other heart rhythm problems. Tell your healthcare provider right away if you faint or have changes in your heart rate or rhythm, such as fast or skipping heartbeat.

Antibiotic-associated Diarrhea. An overgrowth of germs Clostridioides difficile, or "C. diff," can happen in your gut with many types of antibiotics, including azithromycin. This can cause a condition known as antibiotic-associated diarrhea and can happen even up to 2 months after stopping the antibiotic. Call your healthcare provider right away if you have any of the following symptoms of this condition.

• Watery diarrhea
• Diarrhea that does not go away
• Blood in your poop
• Severe stomach cramps
• Fever that starts after you start or finish the medicine

Infantile Hypertrophic Pyloric Stenosis. A condition called infantile hypertrophic pyloric stenosis can happen in babies who are less than 6 weeks old after being given azithromycin. This condition makes it harder for food to move from the baby’s stomach into their intestines, causing vomiting and trouble keeping food down. Call your healthcare provider right away if your baby throws up or is irritable after feeding.