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Azithromycin

(a-ZITH-roe-MY-sin)

For treating mild to moderate bacterial infections

Disclaimer

The content on this page is not medical advice and should be used for informational purposes only. Always consult your health care provider or pharmacist to determine what medication and dosage are right for you.

Last updatedJuly 27, 2021

Azithromycin

Azithromycin is an antibiotic used to treat a range of mild to moderate bacterial infections caused by certain types of bacteria.

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Brand name

Zithromax, Zmax, Z-Pak
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Rx or OTC

Available by prescription only

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Black box warning

Azithromycin can cause abnormal changes in the electrical activity of the heart, which may lead to a potentially fatal irregular heart rhythm.

People at risk include those with known risk factors such as existing QT interval prolongation, low blood levels of potassium or magnesium, a slower than normal heart rate, arrhythmias, or use of certain drugs that treat abnormal heart rhythms.

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When & How

  • Take azithromycin with or without food.
  • Take exactly as prescribed.
  • If taking a liquid, shake the liquid before measuring a dose. Use the dosing syringe provided or a medicine dose-measuring device (do not use a kitchen spoon).
  • If you miss a dose, take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
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Do’s

  • Take azithromycin until you finish the prescription, even if you feel better. Not completing the full course can increase your risk of infection that is resistant to medications.
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Don’ts

  • Do not take azithromycin for the flu, colds, or other viral infections.
  • Do not share your antibiotic with anyone else.
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Discuss with your doctor

  • If you have or had any allergic reaction to azithromycin, erythromycin, clarithromycin, or telithromycin.
  • If you have a history of liver problems such as jaundice from prior use of azithromycin.
  • If you have any heart issues
  • If you are pregnant or breastfeeding. Taking azithromycin while breastfeeding may cause diarrhea, vomiting, or rash in the nursing baby.
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What is Azithromycin?

Azithromycin is a macrolide antibiotic that treats respiratory tract bacterial infections such as bronchitis, pneumonia, and infections of the ears, lungs, sinuses, and throat.

Azithromycin also treats other bacterial infections including skin infections, sexually transmitted infections (STIs), H. pylori, traveler’s diarrhea, other gastrointestinal infections, Legionnaires' disease (a lung infection), pertussis (whooping cough), and babesiosis (a tick-borne infection).

It is also taken before dental procedures to prevent heart infection in people with endocarditis.

Azithromycin is also used to treat or prevent disseminated mycobacterium avium complex (MAC), a lung infection that mostly affects people with HIV.

It is available by prescription only.

Azithromycin dosages
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Tablets and liquids

  • 250 mg tablet
  • 500 mg tablet
  • 600 mg tablet
  • Powder for mixing with water 1 Gm

Side effects

Disclaimer

Medications may affect individuals differently. Usage of any medication may include side effects and other interactions. Here is a list of known common side effects and interactions. This list is not exhaustive -- there may be other side effects or interactions for this medication that are not listed here. In some cases, the likelihood of side effects or interactions may increase depending on dosage. It’s important to keep in mind that in extreme cases, other serious side effects, even death, may occur. Always consult your health care provider or pharmacist to determine what medication and dosage is right for you.

Common side effects

  • Diarrhea
  • Nausea
  • Abdominal pain
  • Vomiting

Full list of side effects

  • Diarrhea
  • Nausea
  • Abdominal pain
  • Vomiting
  • Fast, pounding, or irregular heartbeat
  • Dizziness
  • Fainting
  • Aggression
  • Anxiety
  • Rash with or without a fever
  • Fever and pus-filled, blister-like sores, redness, and swelling of the skin
  • Hoarseness
  • Yellowing of the skin or eyes
  • Lack of energy
  • Extreme tiredness
  • Unusual bleeding or bruising
  • Loss of appetite
  • Pain in the upper right part of the stomach
  • Flu-like symptoms
  • Dark-colored urine
  • Unusual muscle weakness or difficulty with muscle control
  • Hearing loss, tinnitus
  • Loss of taste/smell
  • Pink and swollen eyes

Long-term complications

  • Long-term use of antibiotics may cause Clostridium difficile infection or severe diarrhea and inflammation of the colon.
  • Exacerbation of myasthenia gravis

Safety notes

  • Azithromycin could make you get sunburned more easily. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.
  • Azithromycin can cause abnormal changes in the electrical activity of the heart, which may lead to a potentially fatal irregular heart rhythm. People at risk include those with known risk factors such as existing QT interval prolongation, low levels of potassium or magnesium in your blood, a slower than normal heart rate, arrhythmias, or use of certain drugs used to treat abnormal heart rhythms.
  • Risk of liver function, hepatitis, cholestatic jaundice, hepatic necrosis, and hepatic failure.

Azithromycin interactions

Disclaimer

Medications may affect individuals differently. Usage of any medication may include side effects and other interactions. Here is a list of known common side effects and interactions. This list is not exhaustive -- there may be other side effects or interactions for this medication that are not listed here. In some cases, the likelihood of side effects or interactions may increase depending on dosage. It’s important to keep in mind that in extreme cases, other serious side effects, even death, may occur. Always consult your health care provider or pharmacist to determine what medication and dosage is right for you.

Tell your doctor if you are taking any of these medications or supplements

Drugs that should not be taken with azithromycin:

  • Colchicine
  • Digoxin
  • Warfarin, Coumadin, Jantoven—azithromycin increases the effects of blood thinners. Avoid or use alternative therapy.

Drugs that need close monitoring when taking with azithromycin.

  • Nelfinavir—Increases levels of azithromycin
  • Phenytoin (Dilantin)—azithromycin decreases the effect of phenytoin.
  • Antacids that contain aluminum or magnesium may decrease azithromycin absorption, making it less effective. These include Acid Gone, Gaviscon, Gelusil, Maalox, Milk of Magnesia, Mylanta, Pepcid Complete, Rolaids, Rulox, and others.

Tell your doctor if you have any of these pre-existing conditions

You should not take azithromycin if you have any of these risk factors:

  • Moderate to severe pneumonia
  • Cystic fibrosis
  • Hospital-acquired infections
  • Having a known or suspected infection in the blood (sepsis)
  • Infections requiring hospitalization
  • A weak immune system caused by diseases such as cancer or HIV/AIDS
  • You are an older adult who is very ill or debilitated
  • A heart rhythm disorder
  • A history of long QT syndrome—either you or a family member
  • Low levels of potassium in your blood


Other pre-existing to discuss with your doctor:

  • Have liver or kidney disease
  • Myasthenia gravis
  • Pregnancy
  • Breastfeeding: Taking azithromycin while breastfeeding may cause diarrhea, vomiting, or rash in the nursing baby.

Azithromycin pricing

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