Azithromycin for infection
Zithromax
Peer reviewed by Dr Colin Tidy, MRCGPLast updated by Michael Stewart, MRPharmSLast updated 22 May 2023
Meets Patient’s editorial guidelines
- DownloadDownload
- Share
- Language
- Discussion
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.
The most common side effects of azithromycin are diarrhoea, feeling sick (nausea) and headache.
In this article:
Continue reading below
About azithromycin
Type of medicine | A macrolide antibiotic |
Used for | Bacterial infections |
Also called | Zithromax® |
Available as | Tablets, capsules, oral liquid medicine and eye drops |
What is azithromycin used for?
Azithromycin is a type of antibiotic used to treat acute bacterial infections, such as respiratory infections, ear infections, skin infections and some genital infections.
Azithromycin is also available as an eye drop for the treatment of eye infections.
It works by stopping the bacteria causing the infection from multiplying.
Azithromycin can be taken by adults and children.
Continue reading below
Side effects of azithromycin
Common side effects of azithromycin are:
Diarrhoea.
Feeling sick.
Being sick.
Stomach ache.
Farting (wind).
Headache.
Lack of appetite.
Feeling of deafness.
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.
How to manage azithromycin side effects
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 or being sick, stomach ache, farting | 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.
Continue reading below
Who should not take azithromycin?
Some medicines are not suitable for people with certain conditions. Before starting 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
Read the leaflet in the pack before starting azithromycin. It explains how to take it and lists possible side effects.
Take exactly as your doctor tells you to and always check the label for the correct dose.
It is usually taken once a day as a single dose.
You may be given a course for 3-5 days depending on the reason for taking it.
If prescribed for a child, the dose will depend on the child's weight.
Use the measuring syringe provided and check the label carefully. A drink of juice afterward can help with the bitter taste.
If you're taking capsules, take you dose on an empty stomach. Either one hour before food or two hours after food.
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.
Finish the full course even if you feel better, unless your doctor tells you to stop.
Getting the most from your treatment
Avoid taking antacids within 2 hours before or after azithromycin, as they can slow down how your body absorbs the medicine.
Some people develop thrush (oral or vaginal) 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.
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
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.
Report side effects to a medicine or vaccine
If you experience side effects, you can report them online through the Yellow Card website.
Frequently asked questions
How long does it take for azithromycin to work?
Azithromycin usually starts to improve symptoms within 1-3 days. Full recovery depends on the infection but often takes 5-7 days, even if the antibiotic course has finished.
Why is azithromycin only given for three days?
Azithromycin has a long half-life, so it stays in the body and continues to fight bacteria after the last dose. This allows a short, effective 3-day course for many infections.
Is it safe to take azithromycin during pregnancy?
Azithromycin is generally considered safe in pregnancy when prescribed by a doctor. Your healthcare provider will weigh the benefits and risks before recommending it.
Can you drink alcohol with azithromycin?
Drinking alcohol while taking azithromycin is not usually dangerous, but it can increase the risk of side effects like stomach upset or dizziness. Limiting alcohol can help you recover more comfortably.
Is azithromycin a penicillin?
No, azithromycin is not a penicillin. It belongs to the macrolide class of antibiotics and works differently from penicillin.
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.
Continue reading below
Article history
The information on this page is written and peer reviewed by qualified clinicians.
Next review due: 21 May 2026
22 May 2023 | Latest version

Ask, share, connect.
Browse discussions, ask questions, and share experiences across hundreds of health topics.

Feeling unwell?
Assess your symptoms online for free
Sign up to the Patient newsletter
Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.
By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.