Sounds like 'ay-ZITH-ro-MYE-sin'

Easy-to-read medicine information about azithromycin – what it is, how to take azithromycin safely and possible side effects.

Type of medicine Also called
  • Antibiotic
  • Belongs to a group of antibiotics known as macrolides
  • Zithromax®
  • Apo-Azithromycin®

What is azithromycin?

  • Azithromycin is an antibiotic that is used to treat chest infections such as whooping cough, or infections of the ear, skin or genitals such as gonorrhoea or chlamydia
  • Azithromycin is also used to prevent infections in people with cystic fibrosis
  • It works by killing or stopping the growth of the bugs that cause the infection.
  • Azithromycin is available as tablets and a liquid suspension (for use in children).


  • The dose of azithromycin will be different for different people depending on the type of infection and your age. 
  • Your doctor will advise you how long to take azithromycin for.
  • For genital infections, gonorrhoea and chlamydia, azithromycin is taken a single 1 gram dose (2 x 500 milligram tablets).
  • For other infections, azithromycin is taken as a course for 3 to 5 days.
  • The dose for children will depend on their body weight.
  • Always take your azithromycin exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much to take, how often to take it, and any special instructions.

How to take azithromycin

  • Tablet: swallow your azithromycin tablet with a glass of water.
  • Liquid: measure azithromycin liquid carefully with an oral syringe or measuring spoon. Shake the bottle well before measuring each dose. 
  • Azithromycin is usually taken once a day. Take your dose at about the same time each day.
  • You can take azithromycin with or without food.
  • Keep taking azithromycin until you finish the course, or for as long as your doctor or pharmacist tells you to.
  • Do not stop taking azithromycin, even if you feel better after a few days, unless your doctor tells you to.
  • If you forget to take azithromycin, take it as soon as you remember. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.

Precautions - before starting azithromycin

  • Are you pregnant or breast-feeding?
  • Do you have problems with the way your liver or kidneys work?
  • Do you know if you have an unusual heart rhythm?
  • Are you taking warfarin?
  • Are taking any other medicines? This includes any medicines you are taking which you can buy without a prescription, as well as herbal and complementary medicines.

If so, it’s important that you tell your doctor or pharmacist before you start azithromycin. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Possible side effects

Like all medicines azithromycin can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Stomach upset
  • Feeling bloated, gas in the tummy
  • Tummy ache
  • Take with food
  • Tell your doctor if troublesome
  • Feeling sick, nausea or mild diarrhoea (runny stools)
  • Headache
  • Tell your doctor if troublesome
  • Vaginal itch or discharge (thrush)
  • Small white sores in the mouth (oral thrush)
  • Tell your doctor
  • Fainting or feeling like your heart is beating too fast
  • Signs of problems with your liver such as yellowing of the skin or eyes, dark urine, pain in the tummy
  • Tell your doctor immediately or ring HealthLine 0800 611 116


Azithromycin may interact with some medicines, including warfarin, and herbal supplements, so check with your doctor or pharmacist before you start taking azithromycin.

Learn more

Azithromycin New Zealand Formulary

Azithromycin (for chlamydia) New Zealand Formulary

Zithromax Medsafe Consumer Information Sheet   


  1. azithromycin New Zealand Formulary
  2. Check INR after starting roxithromycin for patients on warfarin Medsafe 2015
  3. Upfront: Azithromycin: use it wisely BPAC, April 2014
  4. News and updates: Update on azithromycin BPAC, November 2012
Credits: Sandra Ponen, Pharmacist. Last reviewed: 12 Jan 2018