Antibiotics

What are antibiotics?

Antibiotics are medicines used to treat infections caused by bacteria. Two types of germs cause most infections: viruses and bacteria. Antibiotics will not cure infections caused by viruses, such as colds and the flu.

When are they used?

Antibiotics are used to treat illnesses such as strep throat, ear infections, bacterial pneumonia, and urinary tract infections. In special cases, antibiotics may be given to prevent infection.

When are antibiotics not needed?

Taking antibiotics when you do not need them can cause problems when you do need them. Bacteria can change and become able to defend themselves against antibiotics. Those bacteria are called antibiotic resistant. An antibiotic that used to work well may no longer kill the bacteria. Then a stronger antibiotic must be used.

Your health care provider will decide whether antibiotics should be used based on the specific diagnosis. Here are a few examples:

Colds. Antibiotics have no effect on colds.
Cough or bronchitis. Antibiotics are rarely needed for bronchitis.
Ear infections. Some types of ear infections need antibiotics, but mild ones do not.
Sinus infections. Thick or green mucus does not always mean a sinus infection. Antibiotics may be needed for some long lasting or severe cases.
Sore throat. Most sore throats are caused by viruses. Strep throat is treated with antibiotics. Strep throat must be diagnosed by a lab test.

How do they work?

Antibiotics cure infections either by killing bacteria or by stopping their growth. Once growth is stopped, the body's normal defenses can attack the bacteria. There are many types of antibiotics. Each works a little differently on different bacteria.

Antibiotics may come in different forms, such as liquids, pills, shots, drops, lotions, and gels. Your health care provider will choose which medicine will work best for your infection.

What should I watch out for?

Antibiotics are usually very safe and effective if taken correctly. However, they may interact with many other drugs. Tell your health care provider about all medicines, herbs, and vitamins that you take. Make sure you tell your provider and pharmacist about any drug allergies you have, and if you have had side effects from any drugs.

Antibiotics work best if you:

Take them exactly as directed.
Take antibiotics for as long as your health care provider prescribes, even if you feel better. If you stop taking the medicine too soon, you may not kill all the bacteria and you may get sick again.
Take only antibiotics that are prescribed for you. Do not share medicines with other people.
Never use leftover antibiotics.

Many antibiotics have side effects. The most common are upset stomach, diarrhea, and rashes. Ask your pharmacist if you can take the antibiotic with food. Taking medicines with meals may lessen the chance that they will upset your stomach. However, some antibiotics should not be taken with milk or food. If you have side effects, do not stop taking the antibiotic. First call your provider or pharmacist for advice.

When should I call my health care provider?

Call your health care provider if you are taking an antibiotic but:

Your symptoms get worse.
Your symptoms do not improve as soon as your provider told you to expect.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File MED4252F.HTM Release 9.0/2006