Please note: This information was current at the time of publication but now may be out of date. This handout provides a general overview and may not apply to everyone. 

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Am Fam Physician. 2004;70(7):1345-1346

What are antibiotics?

Antibiotics (say: “ant-eye-by-ah-tiks”) are medicines that can stop some infections and can even save lives. But antibiotics can do more harm than good if they are not used the right way. You can protect yourself and your family by knowing when you should use antibiotics and when you should not.

Do antibiotics work against all infections?

No. Antibiotics only work against infections caused by germs. They do not work against infections caused by viruses. Viruses cause colds, the flu, and most coughs and sore throats.

What is “antibiotic resistance”?

When germs are exposed to the same antibiotic again and again, the antibiotic stops working. Being exposed to the same antibiotic for a long time can make some germs change. These changes make the germs so strong that they can fight back against antibiotics. Then these germs are said to be “resistant” to this antibiotic.

Antibiotic resistance is becoming a problem in many parts of the United States. Resistant germs grow faster when antibiotics are used too often or are not used the right way.

Resistant germs sometimes can be treated with different antibiotics. You might have to go to a hospital to get these medicines through a needle in your vein. Some kinds of resistant germs cannot be treated.

Why should I worry about antibiotic resistance?

If you take antibiotics that cannot fight the germs they are supposed to kill, your infection can last longer. Instead of getting better, your infection might get worse. You might have to make several visits to your doctor’s office. You might have to take different medicines or go to a hospital for stronger antibiotics.

Your family members or other people you come in contact with may catch the resistant germs that you have. Then they could get infections that are hard to cure.

Every time you take antibiotics when you do not really need them, you increase the chance that you will get an illness that is caused by germs that are resistant to antibiotics.

How do I know if I need to take antibiotics?

It depends on what is causing your infection. These are some basic guidelines:

  • Colds and flu are caused by viruses. They cannot be cured with antibiotics.

  • Cough and bronchitis are almost always caused by viruses. But if these problems do not go away, germs may be the cause. Your doctor may want you to take an antibiotic.

  • A sore throat is usually caused by a virus and cannot be cured with an antibiotic. But strep throat is caused by germs. Your doctor will do a lab test before prescribing an antibiotic for strep throat.

  • Ear infections can be caused by viruses or germs. Antibiotics sometimes are used for ear infections, but they are not always needed. Antibiotics do not work for infections caused by viruses.

  • Sinus infections can be caused by viruses or germs. Antibiotics sometimes are used to treat sinus infections. But a runny nose with yellow or green mucus does not always mean you need to take an antibiotic.

How should I take the antibiotics that my doctor prescribes?

Follow your doctor’s directions carefully. Your doctor will tell you to take all of your antibiotic. Never save some of the medicine for the next time you are sick.

What else can I do to reduce the risk of antibiotic resistance?

Wash your hands with soap and water before you eat and after you use the bathroom. Regular handwashing will help keep you healthy and keep you from spreading germs.

Ask your doctor if you have all the shots you need to help keep you from getting sick.

Where can I get more information?

Your doctor.

Centers for Disease Control and Prevention

Alliance for the Prudent Use of Antibiotics

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