Antibiotics: When You Need Them and When You Don’t

You don’t feel well. You’re not sure if you have a cold or strep throat—and you’re not sure how to treat it.

Do you need an antibiotic, or just rest and an over-the-counter pain reliever? The answer depends on whether a virus or a bacteria has caused your illness.

Antibiotics should only be used to treat illnesses caused by bacteria.

“Antibiotics are used to treat or prevent illnesses caused by a bacteria that your body will not be able to clear on its own,” says Mavis A. Agyeiwaah, MD, a family medicine doctor at Valley Health Winchester Family Practice. “Antibiotics kill bacteria or prevent them from growing and spreading. Antibiotics cannot help with infections that are not caused by a bacteria, such as viruses that cause a cold.”

Common illnesses treated by antibiotics, according to the Centers for Disease Control and Prevention, include:

• Strep throat
• Urinary tract infection
• Some skin infections, like cellulitis

Antibiotics DO NOT work on viruses, such as those that cause:

• Colds and runny noses, even if the mucus is thick, yellow, or green
• Most sore throats (except strep throat)
• Flu
• Most cases of chest colds (bronchitis)

Antibiotics also ARE NOT needed for some common bacterial infections, including:

• Many sinus infections
• Some ear infections (Some ear infections, such as middle ear infections, need antibiotic treatment, but many can get better without antibiotics.)

So what happens if I take an antibiotic when I don’t need it?

“If you take an antibiotic when you don't need it, it can make you feel worse,” says Dr. Agyeiwaah. “It can even make your illness last longer. Also, antibiotics have many side effects and can cause you to develop problems you did not have before, such as diarrhea, nausea and rashes on your skin.”

Taking an antibiotic when you don’t need it can also make your body resistant to antibiotics.

“This means that the next time you really need antibiotics to fight a bacterial infection, they may not work as well to cure you,” says Dr. Agyeiwaah.

It is very important to talk to your medical provider before taking any antibiotic.

If your doctor decides an antibiotic is the best treatment when you’re sick:

• Take them exactly as your doctor tells you
• Do not share your antibiotics with others
• Do not save them for later
• Do not take antibiotics prescribed for someone else