Antibiotics kill only bacteria. They don’t work against viruses. Most common colds and sore throats are caused by viruses. Sometimes when you take an antibiotic, the bacteria may be resistant or become resistant. Resistant bacteria aren't killed by the antibiotic. They continue to cause infection. You should take antibiotics only when you need to. Each time you take an antibiotic when you don’t need to, you raise your chances of having drug-resistant bacteria. This can happen if you take an antibiotic for a viral infection. It can also happen if you don’t take all of your antibiotic prescription. Resistant bacteria have made certain infectious diseases harder to treat. These diseases include tuberculosis, pneumonia, and meningitis. Once a certain type of bacteria is resistant to a medicine, it can pass on that resistance to other types of bacteria.

Viruses cause most colds and the flu. They also cause most coughs and most sore throats. Antibiotics can’t kill viruses. But certain antiviral medicines can work for the flu. Taking an antibiotic for a cold or the flu will not help you get better faster. It may also make some bacteria resistant. This also can happen in children. Children often play together and can easily pass resistant bacteria onto others. This makes the problem worse. Your healthcare provider will probably prescribe an antibiotic if you have an ear infection, a chronic sinus infection, strep throat, or a urinary tract infection. Many of these infections are caused by bacteria.

These antibiotics are called narrow-spectrum antibiotics. The other category of antibiotics is broad-spectrum. Broad-spectrum antibiotics are used to treat a broader number of bacteria types. They are also used if the bacteria causing the infection are unknown. Unfortunately, more and more healthcare providers prescribe the broad-spectrum antibiotics for less serious infections. Experts worry that using these broad-spectrum antibiotics too often will cause more bacterial resistance. These broad-spectrum antibiotics may also cost more than narrow-spectrum antibiotics.

It's important to take all of the medicine prescribed for your illness. If you stop taking the medicine before you have finished it all, some of the bacteria that caused your illness may still be in your body. If the bacteria are exposed to only a small dose of an antibiotic or if an antibiotic is not given enough time to kill the bacteria, the remaining bacteria may develop resistance to the antibiotic. The smaller amount of bacteria that remain may also replicate and cause symptoms all over again. Resistant bacteria can also pass from person to person. This makes infections increasingly harder to treat.

You should not take antibiotics left over from an earlier illness. These antibiotics may not be the correct choice for your current infection. Even if they are correct, they would likely make up only a part of a treatment course. This would not be enough to completely fight off a bacterial infection and could create bacterial resistance. Antibiotics also may not work if they are old, because they go bad after a time. The antibiotic you stored on your shelf may have expired. More important, your current illness may not be caused by bacteria, but by a virus. This would make the antibiotics useless. Never share antibiotics with others. The medicine is meant only for you and for the very specific infection it is treating. Always check with your healthcare provider before taking any antibiotic.

That's why taking an antibiotic can cause symptoms that mean you don’t have enough good bacteria. These symptoms include diarrhea, vaginal yeast infections, oral thrush, and an inflammation of the small intestine and colon (C. difficile enterocolitis). If you have any of these side effects, be sure to tell your healthcare provider.

Using antibiotics when you don’t need them helps bacteria become resistant. It may also expose you to unnecessary side effects. Many of the prescriptions written each year aren’t needed. That’s because they are prescribed for the common cold and other viral infections. Ask your healthcare provider why an antibiotic was not prescribed for your illness, but don't demand one. Your provider is the best source of information on using antibiotics.

Many antibiotics are safe to take if you are pregnant or breastfeeding. But some are not. Some of these medicines can affect your growing fetus. Your healthcare provider will make the correct choice of medicine for you. Be sure to tell your healthcare provider if you are breastfeeding.

Although hospitals and other medical facilities use antibacterial soaps, they follow strict guidelines for their use. Some health experts worry that using antibacterial soaps at home can make bacteria resistant to these soaps. Studies have not proved that these soaps work any better than ordinary soaps to get rid of bacteria. In fact, they may be harmful to health. Most of the soaps containing antibacterial chemicals are now being removed from the market. Good ways to prevent infections include washing your hands often and staying up to date on vaccines.

Many people believe this, but it's not true. People don't become resistant to bacteria. It is the bacteria themselves that become resistant to antibiotics.