Antibiotics are used to treat or prevent some types of bacterial infection. They kill bacteria or prevent them from reproducing and spreading.
Antibiotics may be used to treat bacterial infections that:
Antibiotics are sometimes given as a precaution to prevent an infection. This is known as antibiotic prophylaxis.
Antibiotics may be needed to prevent infection if you:
Antibiotics do not work against viral infections. This includes the common cold, flu, most coughs and sore throats.
Antibiotics are not often prescribed for mild bacterial infections. This is because your immune system can usually clear these on it’s own.
There are different types of antibiotic. Most can be put into 6 different groups. These are:
Tell your healthcare professional if you’re pregnant, breastfeeding, have a health condition, or have ever had an allergic reaction to antibiotics. Some types of antibiotic may not be suitable for you.
Antibiotics can be given in different ways, including:
Your healthcare professional or pharmacist will tell you how to take your antibiotic. You should follow the directions on the label. Read the patient information leaflet that comes with your medicine too. If you have any questions about taking an antibiotic, ask your pharmacist for advice.
You must finish taking your course of antibiotics, even if you feel better. If you stop taking your antibiotics early, bacteria can become resistant to it.
If you forget to take a dose of your antibiotics, take that dose as soon as you remember. You should then continue to take your course of antibiotics as normal.
If it’s almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Don’t take a double dose to make up for a missed one.
There’s an increased risk of side effects if you take 2 doses closer together than recommended.
If you accidentally take 1 extra dose of your antibiotic, it’s unlikely to cause serious harm. But, it will increase your chances of side effects like:
If your GP or pharmacy is closed, phone 111.
Antibiotics can have side effects. These side effects are usually mild and should pass once you finish your course of treatment.
The most common side effects of antibiotics affect the digestive system. Symptoms can include:
If you experience any other side effects, contact your GP or the doctor in charge of your care for advice.
Some people have an allergic reaction to antibiotics, especially penicillin and cephalosporins. In most cases, the allergic reaction is mild to moderate. It can cause:
Mild to moderate allergic reactions can usually be treated by taking antihistamines.
In rare cases, an antibiotic can cause anaphylaxis. This is a severe and potentially life-threatening allergic reaction. Anaphylaxis is a medical emergency and should be treated quickly.
You or someone else has taken antibiotics and has:
Some antibiotics can interact with:
If you want to check that your medicines are safe to take with your antibiotics, ask your GP or local pharmacist.
Antibiotics are no longer routinely used to treat infections. This is because:
The overuse of antibiotics also means they’re becoming less effective. This has led to the emergence of ‘superbugs’. These are strains of bacteria that have developed resistance to many different antibiotics. These types of infections can be serious and challenging to treat.
New strains of bacteria may develop that antibiotics won’t be able to treat.
Last updated:
29 February 2024