Antibiotics: When you need them—and when you don’t

Now that winter—and cold and flu season—have arrived, you may find yourself at the doctor’s office looking for some relief. But if your illness is caused by a virus, taking antibiotics will do more harm than good.

By Cristela Tello 

That’s because antibiotics don’t work against illnesses caused by viruses (like colds and flu) – they’re only effective against bacterial infections.

“Antibiotics work in many different ways,” says Dr. Janine McCready, infectious diseases physician at Michael Garron Hospital, “but they all interfere with bacterial growth to prevent them from causing infection.”

Antibiotics can help our bodies fight something as simple as strep throat or more complex infections like meningitis or tuberculosis. They are also used before surgeries to prevent an infection afterwards.

Overuse is leading to antibiotic resistance

But Dr. McCready warns that patients should tread cautiously, because while antibiotics can be life-saving, they can also produce a number of unwanted side effects, including antibiotic resistance.

“Antibiotic resistance happens when the bacteria learn to outsmart the drugs, and then those antibiotics don’t work anymore,” says Dr. McCready. “In these cases, physicians need to prescribe even stronger antibiotics and sometimes, bacteria are resistant to every kind of antibiotic.”

Antibiotic resistance is a product of overprescribing antibiotics. According to the CDC at least 30% of antibiotics in the out-patient setting are unnecessary. If this trend continues, estimates are that by 2050 more people will die from causes directly related to antimicrobial resistance than from cancer.

Think twice, get advice 

If you think you have an infection, Dr. McCready recommends considering the following before you start antibiotics:

  • Understand why you’re taking antibiotics.  There should be a clear indication for the antibiotics and not “just in case” of bacterial infection.  
  • Be aware of the side effects.  Not all antibiotics are the same and some are more likely to cause side effects than others.
  • If you have recurring infections, such as a urinary tract infection, ask your doctor to try to figure out why and treat the underlying cause instead of taking multiple courses of antibiotics.
  • If your doctor thinks your infection is due to a virus and not bacteria, don’t insist on antibiotics as there will be no benefit, and they won’t help you get better.
  • If you have a penicillin allergy, ask to be tested.  The majority of penicillin allergies resolve with time.