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.
This content is reviewed periodically and is subject to
change as new health information becomes available. The
information is intended to inform and educate and is not a
replacement for medical evaluation, advice, diagnosis or
treatment by a healthcare professional.
Copyright © 2005 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.