Antibiotics - Uses 

Uses of antibiotics 

Antibiotics are no longer routinely used to treat infections for a number of important reasons:

  • many infections are caused by viruses so antibiotics are not effective
  • even if the infection is bacterial, the use of antibiotics is unlikely to have much benefit in terms of speeding up the healing process and can cause unpleasant side effects
  • the more antibiotics are used to treat trivial conditions the more likely they are to become ineffective in treating more serious conditions because of antibiotic resistance

For example, antibiotics are now no longer routinely used to treat chest infections, ear infections in children and sore throats.

Your GP will only prescribe antibiotics to treat:

  • conditions that are not especially serious but are unlikely to clear up without the use of antibiotics, such as moderately severe acne
  • conditions that are not especially serious but could spread to other people if not promptly treated, such as the skin infection impetigo or the sexually transmitted infection chlamydia
  • conditions where there is evidence that using antibiotics would significantly speed up the recovery time, such as a kidney infection
  • conditions that carry a risk of causing more serious complications, such as cellulitis (an infection of the deeper layer of the skin) or pneumonia (lung infection)

Antibiotics may also be recommended for people who are more vulnerable to the harmful effects of infection. This may include:

  • people aged over 75 years
  • people with heart failure
  • people who have to take insulin to control their diabetes
  • people with a weakened immune system – either due to an underlying health condition such as HIV or as a side effect of certain treatments such as chemotherapy

Intravenous antibiotics

Intravenous antibiotics (injections or infusions of antibiotics directly into the blood or, less commonly, the muscles) are usually only required to treat more serious bacterial infections, such as:

Antibiotics to prevent infection

There are several circumstances in which you may be given antibiotics as a precaution to prevent, rather than treat, an infection. This is known as antibiotic prophylaxis.

For example, antibiotic prophylaxis is normally recommended if you are having surgery on a certain part of the body that is known to carry a high risk of infection or that could lead to devastating effects if it were to become accidentally infected.

For example, it may be used if you are going to have:

Your surgical team will be able to tell you if you require antibiotic prophylaxis.

Antibiotic prophylaxis may also be recommended if you have a bite or wound that has a high chance of becoming infected, for example because it has come into contact with soil or faeces.  

There are also several medical conditions that make people particularly vulnerable to infection, meaning antibiotic prophylaxis is necessary. For example, people with the blood disorder sickle cell anaemia often have to take antibiotics for the rest of their lives as their spleen does not work properly. (The spleen plays an important role in filtering out harmful bacteria from the blood.)  

Page last reviewed: 07/03/2012

Next review due: 07/03/2014


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Antibiotic resistance

Antibiotics cannot treat colds, most coughs and sore throats. Get the facts about antibiotics and learn more about the annual European Antibiotic Awareness Day (EAAD)