How do antibiotics work, and why are they prescribed?

Dr. Hodges discusses how antibiotics work and why they are prescribed. Click play to watch the video or read the transcript.


Antibiotics are strong medicines that fight bacterial infections by killing the bacteria or keeping them from reproducing, according to the National Institutes of Health (NIH).

Antibiotics are prescribed to fight off bacterial infections until your body’s natural defenses are strong enough to take over as you work your way back to health, according to the NIH.

According to the American Academy of Family Physicians (AAFP), some reasons your doctor might prescribe an antibiotic include:

  • Cough or bronchitis – Usually, these illnesses are caused by viruses. When symptoms last a long time, it may be determined that they are caused by bacteria. In those cases, your doctor might decide to prescribe an antibiotic.
  • Sore throat – Sore throats are usually caused by viruses and don’t need antibiotics. Bacteria do, however, cause strep throat. If your doctor thinks you have strep throat, you will be tested to determine whether you need an antibiotic.
  • Ear infections – Antibiotics work to care for some but not all ear infections.
  • Sinus infections – Physicians often prescribe antibiotics to treat sinus infections, but discolored mucus from a runny nose does not necessarily mean you have a sinus infection or need an antibiotic.

For more information about how antibiotics work and why they might be prescribed, talk with your physician.

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