Antibiotics: information for patients and carers


What are antibiotics?

Antibiotics are used to treat and prevent infections caused by bacteria. They work by killing the bacteria or stopping them from increasing in number. They are not effective against viral infections such as common colds or flu.

Different types of antibiotics are used to treat different infections.

How and when to take antibiotics

Antibiotics are given for a specific period of time, normally 5-7 days. You should space the doses evenly during the day. You do not need to wake up especially to take them during the night.

Many antibiotics cannot be taken with certain foods or drinks because they make the antibiotic less effective, reducing the chance of a full recovery. For further details refer to the information leaflet included with your antibiotics.

Even if you start to feel better before the antibiotic course is complete, continue taking them until the course is finished. 

Possible side effects of antibiotics

All medicines can cause side effects, however not everybody gets them. The most common side effects are diarrhoea and feeling/being sick. After treatment with certain antibiotics, you might get a fungal infection such as thrush.

For further details refer to the information leaflet included with your antibiotics.

Allergic reactions

Most antibiotic reactions are side effects, rather than true allergies, e.g. nausea or diarrhoea. Unlike allergies, side effects do not prevent you from having the antibiotics again in the future.

If you are allergic to antibiotics, you may get symptoms such as a rash and itching or, in severe cases difficulty breathing. If you experience difficulty breathing, you should ring for an ambulance straight away.

Antibiotic resistance

Misuse of antibiotics causes bacteria to become resistant to antibiotic treatments meaning that, if you need antibiotics in the future, they may not work. 

The NHS and other health organisations across the world are trying to reduce the inappropriate use of antibiotics to prevent the rise of “superbugs”. A “superbug” is a strain of a bacteria that has developed resistance to many antibiotics such as MRSA.

How you can help prevent antibiotic resistance

Always complete the full course of antibiotics unless your doctor advises you otherwise. Do not ‘save’ antibiotics for the next time you or a family member is sick.

Always ask your pharmacist about how to safely dispose of any remaining antibiotics. 

Interactions with other medicines

Medicines can affect or be affected by other medicines or herbal remedies. Check with your doctor or pharmacist about drug interactions if you have any concerns. 

How to contact us

Medicines Helpline

01709 304337  
9am to 5pm, Monday to Friday


  • follow the instructions and advice on the labels.
  • ask your pharmacist or doctor if in doubt.
  • store medicines out of reach and sight of children. 

Antibiotics: information for patients and carers - patient information leaflet
Produced by Pharmacy August 2018. Revised May 2021. 
Revision due May 2023. Version: 2.0. 
©The Rotherham NHS Foundation Trust 2021. All rights reserved.  

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