What are antibiotics and how do they work?
Antibiotics are powerful medicines used to treat harmful bacteria — tiny germs that cause disease. One example of a bacterial infection is strep throat. Germs are not all the same. Other types of germs — viruses — cause most colds, sore throats, coughs, and runny noses. Antibiotics do not work against viruses, so you have to let viral infections run their course. Taking an antibiotic for a viral illness may do more harm than good. Each time you take an antibiotic, it kills bacteria. The bacteria that die are called “sensitive.” Some bacteria don’t die; they are called “resistant.” When sensitive bacteria are killed off, it is easier for resistant bacteria to grow and multiply. Illnesses from resistant bacteria can be very serious because they are harder to treat. People infected with resistant bacteria may need to take expensive medicines. Often these drugs are given by vein (IV) in the hospital. A few resistant bacteria can no longer be treated with any antibiotic.
