Azithromycin is an antibiotic medicine.
It's used to treat infections including:
- chest infections such as pneumonia
- ear, nose and throat and nose infections such as sinus infection (sinusitis)
- skin infections
- Lyme disease
- some sexually transmitted infections (STIs)
It can also be used long-term to prevent chest infections in people who keep getting them.
Azithromycin is from a group of medicines called macrolide antibiotics. Macrolide antibiotics work by killing the bacteria that cause the infection.
Azithromycin is available on prescription as capsules, tablets and a liquid that you swallow. It can also be given by injection, but this is usually only done in hospital.
Who can take azithromycin
Most adults and children can take azithromycin.
Azithromycin is not suitable for some people. To make sure it's safe for you, tell your doctor if you have:
- ever had an allergic reaction to azithromycin or any other medicine
- liver or kidney problems
- heart problems, including irregular heartbeats (arrhythmia)
- ever had diarrhoea when you have taken antibiotics before
- myasthenia gravis – azithromycin can make the symptoms of this muscle-weakening condition worse
- diabetes – azithromycin liquid contains sugar
Dosage and strength
Azithromycin tablets come as either 250mg or 500mg strengths. The capsules are 250mg. The liquid comes as 200mg in 5ml.
The usual dose is 500mg a day for 3 to 10 days depending on the infection being treated.
For some infections, you'll be given a one-off higher dose of 1g or 2g.
The dose may be lower for children or if you have liver or kidney problems.
Azithromycin is sometimes prescribed long-term to prevent chest infections if you keep getting them. In this case you will usually need to take it 3 times a week, often on a Monday, Wednesday and Friday.
Carry on taking this medicine until the course is completed, even if you feel better. If you stop your treatment early, your infection could come back.
You'll usually take azithromycin once a day. Try to take your medicine at the same time each day.
Swallow tablets and capsules whole with a drink of water. If you are taking azithromycin capsules, take them at least 1 hour before food or 2 hours after eating. If you have tablets or liquid, you can take them with or without food.
The liquid can have a bitter aftertaste, so it can be a good idea to offer children a drink of fruit juice afterwards.
Do not take medicines for indigestion 2 hours before or after you take this medicine.
Azithromycin liquid is available for children and people who find it difficult to swallow tablets.
If you, or your child, are taking azithromycin as a liquid, your pharmacist will usually make it up for you. The medicine will come with a syringe or spoon to help you measure the right amount. If you do not have one, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.
If you forget to take it
If you forget to take a dose, take it as soon as you remember, unless it's nearly time for your next one. In this case, just leave out the missed dose and take your next dose at the usual time.
Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for other ways to help you remember to take your medicine.
If you take too much
Taking an extra dose of azithromycin is unlikely to harm you or your child. It may, however, increase the chance of temporary side effects, such as feeling or being sick or diarrhoea.
Talk to your pharmacist or doctor if you're worried, or if you or your child take more than 1 extra dose.
Like all medicines, azithromycin can cause side effects, although not everyone gets them.
Common side effects
These common side effects of azithromycin happen in more than 1 in 100 people. There are things you can do to help cope with them:
Keep taking the medicine, but talk to your doctor or pharmacist if these side effects bother you or do not go away.
Serious side effects are rare and happen in less than 1 in 1,000 people.
Call a doctor or contact 111 now if:
- you have a faster or irregular heartbeat (arrhythmia)
- the whites of your eyes turn yellow, or your skin turns yellow (this may be less noticeable on brown or black skin), or you have pale poo with dark pee – these can be signs of liver or gallbladder problems
- you get ringing in your ears (tinnitus), temporary hearing loss, or you feel unsteady on your feet (vertigo)
- you have severe pain in your stomach or back – this can be a sign of inflammation of the pancreas (pancreatitis)
- you have diarrhoea (perhaps with muscle cramps) that contains blood or mucus – if you have severe diarrhoea without blood or mucus for more than 4 days you should also speak to a doctor
- you have chest pain – this could be a sign of heart attack
In rare cases it's possible to have a serious allergic reaction (anaphylaxis) to azithromycin.
These are not all the side effects of azithromycin. For a full list see the leaflet inside your medicines packet.
Azithromycin and pregnancy
Azithromycin is generally thought to be OK to take during pregnancy if you have an infection that needs treatment. However, other antibiotics may be more suitable for you, depending on your type of infection.
Talk to your doctor about taking azithromycin as it should only be taken if the benefits outweigh the possible risks.
If your doctor or health visitor says that your baby is healthy, it's OK to take azithromycin while breastfeeding.
Azithromycin passes into breast milk in small amounts. It has not been known to cause any side effects in breastfed babies.
Talk to your health visitor, midwife, pharmacist, or doctor as soon as possible if:
- your baby is not feeding as well as usual or has an upset stomach
- your baby has a rash or oral thrush (a fungal infection in their mouth)
- you have any other concerns about your baby
Azithromycin and fertility
There's no clear evidence to suggest that taking azithromycin reduces fertility in either men or women.
Cautions with other medicines
There are some medicines that do not mix well with azithromycin.
Tell your doctor if you're taking any of these medicines before you start azithromycin:
- antacids for indigestion
- ergotamine or dihydroergotamine – for migraine
- warfarin, to help prevent blood clots
- ciclosporin or tacrolimus – medicines to stop your immune system overreacting
- colchicine, a medicine used for gout and some other inflammatory conditions
- digoxin for some heart problems
- rifabutin, an antibiotic
- nelfinavir, a medicine for HIV
- a statin medicine to lower your cholesterol, such as simvastatin or atorvastatin
Azithromycin can affect your heartbeat, so it's best not to take it with other medicines that have the same side effect.
Tell your doctor if you're taking medicines that can affect your heartbeat, including:
- any medicines for an irregular heartbeat (arrhythmia), such as amiodarone or sotalol
- antidepressants such as citalopram
- antipsychotics used to treat mental health conditions
- some anti-sickness medicines, such as dimperidone
- some antibiotics, such as moxifloxacin
Check the leaflets that come with your medicines and talk to a pharmacist or your doctor if you are worried.
There's not enough information to say that complementary medicines and herbal remedies are safe to take with azithromycin. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.
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