Azithromycin: A Practical Guide to the Macrolide Antibiotic

What azithromycin is

Azithromycin is a macrolide antibiotic. Like other antibiotics in this class, it works by stopping bacteria from making the proteins they need to grow and multiply, which allows your immune system to clear the infection. It is a prescription-only medicine in the UK and across the EU, so a doctor or prescribing pharmacist will decide whether it is right for you.

One practical feature of azithromycin is that it stays in body tissues for a relatively long time. This is why courses are often shorter than for some other antibiotics. Even so, you should always follow the exact instructions on your label rather than guessing.

What it is used for

Doctors may prescribe azithromycin for a range of bacterial infections, including:

• Some chest and respiratory infections
• Certain ear, throat and sinus infections
• Some skin and soft-tissue infections
• Particular sexually transmitted infections

It is important to understand that azithromycin treats bacterial infections only. It will do nothing for viral illnesses such as colds, flu or most sore throats. Taking an antibiotic for a virus offers no benefit and contributes to antibiotic resistance explained. If you want to understand the difference, see bacterial infections explained.

How to take it safely

Follow the dosing schedule your prescriber gives you and read the patient information leaflet that comes in the pack. A few general principles apply:

• Finish the full course. Even if you feel better after a day or two, stopping early can leave surviving bacteria to regrow and may encourage resistance.
• Take it consistently. Try to take each dose at around the same time each day.
• Tell your prescriber about other medicines. Azithromycin can interact with several drugs, including some that affect heart rhythm.

If you miss a dose, the leaflet will explain what to do. Never double up to make up for a forgotten dose unless specifically advised.

Possible side effects

Most people tolerate azithromycin well, but side effects can happen. Common ones include nausea, stomach upset and diarrhoea. These are usually mild. Less commonly, macrolides can affect heart rhythm, so your doctor should know if you have a heart condition or take other heart-related medicines.

Seek urgent medical help if you notice signs of a serious allergic reaction, such as a rash, swelling of the face or throat, or difficulty breathing. An allergy to one macrolide may mean you should avoid others, so always report previous reactions.

Alcohol, contraception and other practical questions

Azithromycin is not in the small group of antibiotics that strongly interact with alcohol, but heavy drinking can worsen stomach side effects and slow recovery, so moderation is sensible. If you take the combined or progestogen-only pill, vomiting or severe diarrhoea during any antibiotic course can reduce how well it is absorbed; ask your pharmacist whether extra precautions are needed.

When to see a doctor

Contact your prescriber if your symptoms do not improve within a few days, get worse, or come back after finishing the course. You should also speak to a healthcare professional before starting treatment if you are pregnant, breastfeeding, have liver or kidney problems, or take regular medication. You can browse our wider antibiotics range or read the related Amoxicillin guide to compare options, and shop all for general health products.

Used correctly and only when genuinely needed, azithromycin is a useful and well-established antibiotic. The single most important thing you can do is take it exactly as directed and complete the course.

General information only — not medical advice. Always read the patient information leaflet and consult a doctor or pharmacist before starting any medication.