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Information from Your Family Doctor

Avoiding Resistance to Antibiotics—When Do I Need an Antibiotic?


Am Fam Physician. 2001 Mar 15;63(6):1097-1098.

What are antibiotics?

Antibiotics are medicines that fight (or prevent) infections that are caused by bacteria. Bacteria are also called germs. If the infection is caused by a virus, antibiotics can't fight the virus.

What is antibiotic resistance?

When bacteria are exposed to the same antibiotics, after a while the antibiotic can't fight the germs anymore. Being exposed to the same antibiotic for a long time can make some germs change. Sometimes germs just change by themselves. Some of the changes make the germs so strong, they can fight back against antibiotics and win the fight. These strong germs can live and multiply, even while you are taking antibiotics. These germs are said to be “resistant” to this antibiotic. Germs can even become resistant to many antibiotics. Antibiotic resistance is becoming a common problem in many parts of the United States.

Do I need to worry about antibiotic resistance?

If your infection is resistant to the antibiotic you are taking, 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 antibiotics given in your veins.

At the same time, your family members or other people you come in contact with may catch the resistant germs that you have. Then these people might also get infections that are hard to cure.

So when is it OK for me to take antibiotics?

Your doctor will want to prescribe antibiotics only for illnesses that are caused by germs. These illnesses include infections such as strep throat, urinary tract infections and ear infections. People sometimes ask their doctor for antibiotics when they have a viral illness, such as a cold, the flu (influenza) or mononucleosis (mono). Antibiotics cannot cure these illnesses.

You should not push your doctor to give you or your children antibiotics for a viral illness. Instead, ask your doctor for things you can do to make you feel better. Every time you take antibiotics when you don't really need them, you increase the chance that you will get an illness someday that is caused by germs that are resistant to antibiotics.

How should I take the antibiotics that my doctor prescribes?

Follow your doctor's directions carefully. Your doctor will tell you to take all the antibiotic. Don't stop taking your antibiotic just because you feel better. Taking less of an antibiotic when you need it will not help prevent antibiotic resistance.

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 hand washing will help keep you healthy and prevent the spread of germs.

Ask your doctor if you have all the vaccinations (shots) you need to protect yourself from illness.

Where can I get more information about antibiotic resistance?

You can get more information about antibiotic resistance from the following places:

Centers for Disease Control and Prevention

Web address:

Alliance for the Prudent Use of Antibiotics

Web address:

This handout is provided to you by your family doctor and the American Academy of Family Physicians. Other health-related information is available from the AAFP online at

This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.


Copyright © 2001 by the American Academy of Family Physicians.
This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP. Contact for copyright questions and/or permission requests.

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