Antibiotics are medicines used to kill bacteria that cause infections.
A doctor will choose an antibiotic to treat an illness based on:
- Whether taking an antibiotic will reduce the length or severity of the illness.
- Whether the person is allergic to any antibiotics.
- How likely it is that a certain antibiotic will kill the bacteria believed to be causing the symptoms.
- The symptoms and the severity of the illness.
- Other medical problems that the person has.
- The person's age. (For example, some antibiotics are not safe for children.)
- Whether a woman is pregnant.