

Information from Your Family Doctor

Antibiotics: When They Can and Can't Help




Am Fam Physician. 2004 Jan 15;69(2):375-376.

What are antibiotics?

Antibiotics are strong medicines that can stop some infections and save lives. But antibiotics can cause 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 shouldn't.

Do antibiotics work against all infections?

No. Antibiotics only work against infections caused by bacteria. They don't work against any infections caused by viruses. Viruses cause colds, the flu, and most coughs and sore throats.

What is “antibiotic resistance”?

When bacteria are repeatedly exposed to the same antibiotics, the antibiotic can't fight the germs anymore. Being exposed to the same antibiotic for a long time can make some germs change. And 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. Then these germs are said to be “resistant” to this antibiotic.

Antibiotic resistance is becoming a common problem in many parts of the United States. Resistant bacteria develop faster when antibiotics are used too often or are not used correctly.

Resistant bacteria sometimes can be treated with antibiotics to which the bacteria have not yet become resistant. These medicines may have to be given intravenously (through a vein) in a hospital. A few kinds of resistant bacteria are untreatable.

Why should I worry about antibiotic resistance?

If you take antibiotics that can't 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 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 they might also get infections that are hard to cure.

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 do I know when I need antibiotics?

The answer depends on what is causing your infection. The following are some basic guidelines:

  • Colds and flu. Viruses cause these illnesses. They can't be cured with antibiotics.

  • Cough or bronchitis. Viruses almost always cause these. However, if you have a problem with your lungs or an illness that lasts a long time, bacteria may be the cause. Your doctor may decide to try using an antibiotic.

  • Sore throat. Most sore throats are caused by viruses and don't need antibiotics. However, strep throat is caused by bacteria. A throat swab and a lab test are usually needed before your doctor will prescribe an antibiotic for strep throat.

  • Ear infections. There are several types of ear infections. Antibiotics are used for some, but not all of them.

  • Sinus infections. Antibiotics are often used to treat sinus infections. A runny nose and yellow or green mucus do not necessarily mean you need 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 the antibiotic. Don't 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 during the daytime 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?

Your doctor.

Centers for Disease Control and Prevention



Alliance for the Prudent Use of Antibiotics





Copyright © 2004 by the American Academy of Family Physicians.

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