Azithromycin is a macrolide antibiotic. It can be taken by people who are allergic to penicillin.
It is important to complete the prescribed course (unless you are told to stop). Otherwise your infection could come back.
Any side-effects are usually mild. The most common are diarrhoea, feeling sick (nausea) and headache.
|Type of medicine||A macrolide antibiotic|
|Used for||Bacterial infections|
|Available as||Tablets, capsules, oral liquid medicine and eye drops|
Azithromycin is prescribed to treat acute bacterial infections, such as respiratory infections, ear infections, skin infections and some genital infections. It can be taken by adults and children. It works by stopping the bacteria causing the infection from multiplying.
Azithromycin is also available as an eye drop for the treatment of eye infections. For more information on this use, see the leaflet Azithromycin eye drops.
Before taking azithromycin
Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking azithromycin it is important that your doctor or pharmacist knows:
- If you are pregnant or breastfeeding.
- If you have any problems with the way your liver works or the way your kidneys work.
- If you know you have an unusual heart rhythm.
- If you have a muscle disorder called myasthenia gravis.
- If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
- If you have ever had an allergic reaction to a medicine.
How to take azithromycin
- Before you start taking the antibiotic, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about azithromycin and provide a full list of the side-effects which you may experience from taking it.
- Take azithromycin exactly as your doctor tells you to. It is taken once a day. Depending upon the reason why you are taking it, you may only need to take a single dose or you may be given a course for 3-5 days. Your doctor or pharmacist will tell you which is right for you. The directions will also be on the label of the pack to remind you.
- When azithromycin is prescribed for a child, the dose will depend upon the child's weight. Make sure you read the label carefully so that you measure out the correct amount of medicine. For younger children, you will be given an oral dosing syringe to measure out the medicine - if you are not sure how to use this, ask your pharmacist to show you. It is a good idea to offer your child a drink of fruit juice after taking azithromycin, as the medicine can have a slightly bitter aftertaste.
- If you are taking azithromycin capsules, you should take your doses when your stomach is empty. This means taking them one hour before any food, or waiting until two hours afterwards. If you are taking tablets or liquid medicine, these can be taken either before or after food.
- If you forget to take a dose, take it as soon as you remember but do not take two doses at the same time.
- Even if you feel your infection has cleared up, keep taking the antibiotic until the course is finished (unless your doctor tells you otherwise). This is to prevent the infection from coming back and being more difficult to treat.
Getting the most from your treatment
- If you are also taking an antacid for indigestion, it can increase the time it takes for azithromycin to be absorbed by your body. Because of this, it is recommended that you do not take indigestion remedies during the two hours before or during the two hours after you take a dose of azithromycin.
- Some people develop thrush (redness and itchiness in the mouth or vagina) after taking a course of antibiotics. If this happens to you, speak with your doctor or pharmacist for advice.
- This antibiotic may stop the oral typhoid vaccine from working. If you are having any vaccinations, make sure the person treating you knows that you are taking this medicine.
- If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking azithromycin.
- If you buy any medicines, check with a pharmacist that they are suitable to take with this antibiotic.
- If you still feel unwell after completing your course of the antibiotic, make another appointment to see your doctor.
Can azithromycin cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with azithromycin. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.
|Common azithromycin side-effects ||What can I do if I experience this?|
|Diarrhoea||Drink plenty of water to replace lost fluids. If the diarrhoea continues or is severe, speak with your doctor as soon as possible|
|Feeling sick (nausea) or being sick (vomiting), stomach ache, wind (flatulence)||Stick to simple meals - avoid rich or spicy food|
|Headache||Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, let your doctor know|
|Lack of appetite, a feeling of deafness||If troublesome, speak with your doctor|
If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.
How to store azithromycin
- Keep all medicines out of the reach and sight of children.
- Store in a cool, dry place, away from direct heat and light.
- If you have been given liquid medicine, it will have been made up by the pharmacy and it lasts for a limited number of days only. Check the expiry date on the bottle and do not use it after this date.
Important information about all medicines
Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.
This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
If you are having an operation or any dental treatment, tell the person carrying out the treatment which medicines you are taking.
Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
If you have any questions about this medicine ask your pharmacist.
Further reading and references
Manufacturer's PIL, Zithromax® 250 mg Capsules; Pfizer Limited, The electronic Medicines Compendium. Dated March 2022.
Manufacturer's PIL, Zithromax® Powder for Oral Suspension; Pfizer Limited, The electronic Medicines Compendium. Dated March 2022.
Medicines Complete BNF 86th Edition; British Medical Association and Royal Pharmaceutical Society of Great Britain, London.