Common and Serious Side Effects of Azithromycin

Azithromycin uses and Prescription
Medically reviewed by Dr. Ola Tarabzuni


Azithromycin belongs to a class of medications known as macrolide antibiotics. It works by killing bacteria. The research found that it is associated with an increased risk of non-cardiovascular death. Hence, if you want to know its usage, precautions, and dosing information read this article till the end.


Some of the indications for Azithromycin include:

  • Azithromycin is often prescribed to treat respiratory tract infections, such as Pneumonia and sinusitis.
  • Azithromycin can treat skin infections, such as cellulitis and impetigo.
  • Azithromycin is sometimes used to treat sexually transmitted diseases like chlamydia and gonorrhea.
  • Azithromycin can treat certain types of ear infections, such as otitis media.
  • Azithromycin can treat certain gastrointestinal infections, such as traveler’s diarrhea.

How to Use Azithromycin?

How often you take the drug depends on the following factors:

  • Your age
  • Your condition that is being treated
  • The severity of your condition
  • Other medical conditions you may have
  • Your reaction to the first dose

You usually take Azithromycin once daily. Try to take medicine with the same time gap every day. You can swallow tablets and capsules with a glass of water. Azithromycin, 500 mg tablet, should be taken at least 1 hour before or after eating your food. Also, you can take your medicine with or without food. It can also be given by injection to treat severe Pneumonia or other inflammatory diseases such as pelvic inflammation. Doctors usually prescribe Azithromycin in hospital settings so that they will determine the dosage.

It must be taken during the recommended duration of treatment, even if you start to feel better, to reduce the chances of the remaining bacteria growing. Also, unnecessary use can increase your risk of getting an infection.

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Dosing Information 

Azithromycin is available in different forms, such as tablets, capsules, and oral suspension. The dosing information may vary depending on the treated condition, the patient’s age and weight, and other factors. The following are general dosing guidelines for Azithromycin:


For adults, the usual dose of Azithromycin oral for Pneumonia is 500 mg once daily for at least two days or a more extended period if the infection is severe. For children, the dosage depends on the child’s weight and the duration of treatment. In the case of children, six months or older, 10 mg/kg is given on day 1, followed by a dose of 5 mg/kg orally every other day for five days.

Skin and soft tissue infections

For adults, the usual dose of Azithromycin for skin and soft tissue infections is 500 mg once daily for three days or a more extended period if the infection is severe. For children, the dosage depends on the child’s weight and the duration of treatment.

Sexually transmitted infections

Azithromycin can treat chlamydia in adults, a single dose of 1 gram of is usually prescribed. To treat chlamydia in infants, 20 mg/kg is given orally daily for three days.

Ear infections

For children, the usual dose of Azithromycin for ear infections is 30 mg/kg, given in a single daily dose for three days.

Pharyngitis or tonsillitis

For adults, the usual dose of Azithromycin is 500 milligrams (mg) on Day 1 (the first day)—next, 250 mg per day for the next five days. For Children two years and older, a dose of 12 milligrams per kilogram (kg) of body weight for five days is usually prescribed.

It’s important to note that dosages may vary depending on the specific condition being treated. A healthcare provider should determine the dosages and duration of treatment based on the individual patient’s needs. It’s essential always to follow your healthcare provider’s instructions carefully when using Azithromycin.

What are the common side effects of Azithromycin?

The common side effects may include the following:

  • Nausea 
  • Headaches 
  • Loss of appetite
  • Dizziness 
  • Feeling tired 

What are the severe side effects of Azithromycin?

Some severe side effects are rare and happen in 1 out of 100 people. These may include:

  • Arrhythmia 
  • Tinnitus
  • Serious allergic reactions
  • Blisters or peeling
  • Diarrhea
  • Pancreatitis 
  • Liver or gallbladder problems.
  • Trouble with swallowing
  • Unpleasant breath odor
  • Unusual bleeding or bruising
  • Unusual tiredness or weakness

Detailed Side Effects of Azithromycin on organ systems

Z-pack side effects include severe allergic reactions, including anaphylaxis and angioedema. These require immediate medical care as they can be life-threatening. In addition, if you notice an azithromycin rash, hives, trouble breathing, trouble swallowing, or any swelling of your hands or face, you should inform a doctor. 

Some severe skin conditions, such as Stevens-Johnson syndrome, acute generalized exanthematous pustulosis, and toxic epidermal necrolysis, are other forms of azithromycin allergic reaction.

Side effects of Z-pack antibiotics may also include noticing black, tarry stools, peeling or loosening of the skin, chest pain, cough, diarrhea, or muscle pain. In addition, some people may experience painful urination, red irritation, or skin lesions. Sore throat, sores, ulcers, white spots in the mouth, swollen glands, bruising, or unusual tiredness are other side effects of Az pack.

Azithromycin diarrhea, after the first dose, is a common occurrence but, in some cases, can be severe. If you experience persistent diarrhea, check with your doctor instead of self-medication.

Azithromycin’s adverse effects also extend to the cardiovascular system. It can cause changes in heart rhythms, causing QT prolongation and affecting the heartbeat, resulting in fainting or other serious side effects in some patients. 

Furthermore, Azithromycin tablets may increase the risk of blurred vision, chest pain, confusion, and lightheadedness. Trouble breathing or Fatigue are some of the other Zithromax side effects.

The side effects of Azithromycin have been classified according to the body system or organ affected:


The most commonly reported side effects include 

  • Diarrhea
  • Nausea
  • Abdominal pain
  • Vomiting


Symptoms include:

  • Palpitations 
  • Chest pain
  • Arrhythmia 
  • Hypotension
  • Cardiovascular death


  • Rash
  • Pruritus
  • Angioedema
  • Photosensitivity reaction
  • Stevens-Johnson syndrome
  • Urticaria
  • Dermatitis
  • Hyperhidrosis
  • Systemic symptoms (DRESS) (rare)
  • Eczema


  • Diarrhea 
  • Nausea
  • Abdominal pain 
  • Vomiting
  • Flatulence 
  • Abdominal discomfort
  • Dyspepsia
  • Gastritis
  • Clostridioides difficile-associated diarrhea


  • Vaginitis
  • Dysuria
  • Metrorrhagia
  • Testicular disorder


  • Decreased neutrophils 
  • Decreased lymphocyte count, decreased hematocrit, decreased hemoglobin
  • Leukopenia, neutropenia, eosinophilia
  • Anemia


  • Hepatitis
  • Abnormal liver function tests
  • Cholestatic jaundice
  • Hepatic failure


  • Hypersensitivity
  • Anaphylactic reaction 


  • Anorexia
  • Decreased blood glucose
  • Increased blood glucose
  • Dehydration


  • Arthralgia 
  • Osteoarthritis
  • Myalgia
  • Back pain

Nervous system

  • Headache
  • Dizziness
  • Paresthesia
  • Tinnitus
  • Vertigo


  • Visual impairment
  • Conjunctivitis


  • Nervousness
  • Insomnia
  • Depersonalization
  • Anxiety


  • Increased blood urea/BUN
  • Increased blood creatinine


  • Dyspnea
  • Pneumonia
  • Pharyngitis
  • Rhinitis

Some side effects may disappear during treatment as your body acclimatizes to the medicine. 

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Use in Specific Population

Azithromycin can work in specific populations, but dosages adjustment is necessary, or caution may be required when using the medication in these groups:

  1. Children: You can use Azithromycin for children, and it often treats ear infections, strep throat, and other bacterial infections in pediatric patients. However, dosage adjustment is necessary based on the child’s weight and age, and healthcare providers may monitor children for potential side effects.
  2. Pregnant women: Azithromycin is safe to use during pregnancy, and doctors sometimes prescribe it to treat bacterial infections in pregnant women. However, healthcare providers may carefully weigh the potential benefits and risks of using the medication during pregnancy.
  3. Breastfeeding women: Azithromycin is excreted into breast milk, but it is generally safe for breastfeeding. However, healthcare providers may advise breastfeeding women to monitor their infants for potential side effects.
  4. Elderly patients: Elderly patients may be more likely to experience side effects from Azithromycin, such as liver problems and cardiac arrhythmias. Healthcare providers may adjust dosages or closely monitor elderly patients when using the medication.


Do not take this antibiotic without your doctor’s prescription. Don’t take Azithromycin if you have had a history of allergic reactions to macrolides and ketolides.

This medicine can also increase the risk of many heart problems. Contact your healthcare provider if you have blurred vision, shortness of breath, or arrhythmia. Do not take other medicines, such as prescription or nonprescription, botanical products, or vitamin supplements, unless discussed with your healthcare provider.

  • Tell your healthcare provider if you have ever had jaundice or other liver problems while taking this antibiotic. Your doctor will most probably suggest you stop taking Azithromycin.
  • Tell your healthcare provider and pharmacist if you are allergic to Azithromycin, clarithromycin, dirithromycin, erythromycin, telithromycin, any other drug, or any of the ingredients used in azithromycin tablets or suspension (liquid). These antibiotics are made up of various ingredients, which you can ask your doctor.

Doctors should not prescribe medicine for the treatment of Pneumonia if a person has the following:

  • Cystic fibrosis
  • A hospital-acquired infection
  • Bacteremia
  • Is debilitated
  • Has immune system problems

Individuals should not rely on this antibiotic to treat syphilis.

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In Case of an Emergency or Overdose

If you overdose on Azithromycin, you could have dangerous drug levels that may cause liver damage and irregular heart rhythm. Call your doctor or local poison control center if you’ve taken too much of this antibiotic. Call 911 or go to the nearest emergency room in case of severe symptoms.

What to do if you Miss a Dose of Azithromycin?

If you have missed an azithromycin dose, take it as soon as possible. If the following amount is almost due, skip the missed one and resume your regular regimen. Do not take double doses to make up for the missed one.

What Should you avoid when you are taking Azithromycin?

Some medicines do not mix well with Azithromycin.

You should tell your healthcare provider if you are taking any of the following medicines before; the next is the answer to what not to take with Azithromycin:

  • Antacids for indigestion
  • Ergotamine or dihydroergotamine – for migraine
  • Warfarin to help prevent blood clots
  • Colchicine, a drug used for gout and some other inflammatory conditions
  • Beta-blockers for some heart issues
  • Nelfinavir, a medicine for HIV
  • A statin medicine to lower the cholesterol level.

Azithromycin can affect your heartbeat, so it is better not to take it with other medicines.

Tell your healthcare provider if you’re taking antibiotics that can affect your heartbeat, including:

  • Arrhythmia
  • Antidepressants such as dapoxetine
  • Antipsychotics used to treat mental health conditions
  • Some anti-sickness medications, such as metoclopramide

Drug Interactions

Azithromycin does not have as many interactions as some other antibacterials. But it still can interact with several drugs. For instance, using Azithromycin while taking colchicine (a drug used for gout and other inflammatory conditions) can be life-threatening or fatal.

Some other drugs that may interact with Azithromycin are:

  • Digoxin, a heart medication
  • Nelfinavir, medication for the treatment of HIV
  • Phenytoin, a seizure medication
  • Antacids that contain magnesium or aluminum


Azithromycin is generally a safe macrolide antibiotic with a statin, but the combination can sometimes increase the rhabdomyolysis risk. Ask your doctor how to manage this drug interaction best. Depending on your risk factors, they may suggest you temporarily lower or stop your statin dose. 


These are medications that treat heartburn. Not all antacids interact with Azithromycin. But some antacids can affect other medicines’ absorption, making them less effective.

You should watch for antacids containing aluminum, magnesium, or calcium salts. 

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It is a blood thinner that helps prevent blood clots. However, it is a sensitive medication. Having too much warfarin can increase the risk of easy bleeding or bruising.

Research has shown mixed results on the interaction between these two antibiotics. One small study found that taking Azithromycin with warfarin may increase bleeding risk.

Before taking Azithromycin, you should tell your healthcare provider about all your current medications, supplements, and remedies. Always speak to your doctor before stopping taking any medicines.

When to Consult a Doctor?

Tell your healthcare provider if you do not feel any better after taking Azithromycin for four days to treat an infection. When taking this medicine, tell your doctor if you experience any complications or feel worse than before. Does Azithromycin make you tired? What are the most common side effects of Azithromycin? Consult our online doctor to find out more!

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FAQs about Azithromycin Answered by Your Doctors Online Team

Is Azithromycin a powerful antibiotic?

It is a powerful antibiotic as it can fight many bacteria. It can also stop the growth of harmful bacteria, but it will not work for viral infections such as colds or flu.

When is Azithromycin best taken?

It is usually taken once a day. You can take at least 1 hour before or after eating your food, same time every day.

Is Azithromycin used for cough and cold?

It can only treat infections caused by certain bacteria and can not work for the common cold, flu, or other viral infections.

How quickly does Azithromycin work?

Azithromycin starts to work as soon as you take the first dose. Oral Azithromycin usually takes 2 to 3 hours to reach its total concentration in your body, but the effects might not be immediately noticeable and take 3-10 days.

Is Azithromycin penicillin?

Azithromycin is not penicillin. It is a type of antibiotic known as macrolide that kills bacteria. Both antibiotics work in different ways and have some differences, such as their drug interactions.

Does Azithromycin treat UTI?

Azithromycin is effective against many bacterial infections such as sinus, ear, urinary tract, cervix, or genital infections. Still, it is not recommended for UTI treatment because it reaches a low urine concentration.

Is Azithromycin stronger than Amoxicillin?

Azithromycin works against a large number of bacterial infections. Amoxicillin is the first-line drug against bacterial infections, but Azithromycin is now more effective due to less bacterial resistance.

How long does Azithromycin stay in your body?

Azithromycin can stay in your system for 14-15 days after taking your last dose.
It has an extended half-life of 68 hours or so.

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