Why Is Finishing Antibiotics So Important?

If you've ever had a bacterial infection, you've probably been prescribed antibiotics to treat it. You also likely remember your doctor telling you that it's important to take all your pills, even after your symptoms have gone away.

But is there really any harm in not finishing antibiotics once it seems they've done their job? To understand the importance of finishing antibiotics, let's first look at what antibiotics are and what they do.

What Are Antibiotics?

Antibiotics are medicines that treat bacterial infections by either killing the bacteria or making it more difficult for them to grow and multiply. Illnesses that can be treated by antibiotics include respiratory tract infections such as whooping cough and pneumonia, as well as skin infections. While antibiotics don't treat most colds, which come from viral infections, they do treat strep throat, as it's caused by streptococcus bacteria.

There are also differences in what types of bacteria antibiotics treat. Broad-spectrum antibiotics such as amoxicillin affect a wide range of bacteria, while narrow-spectrum antibiotics like penicillin only affect a few different types of bacteria.

When in Doubt, Stick to the Guidelines

So why is it that your doctor recommends finishing your course of antibiotics? It's because taking them regularly until the prescription is complete helps ensure that all of the illness-causing bacteria are killed or prevented from multiplying. Even if your symptoms go away, the bacteria may still be present in your body. If you stop treatment before the antibiotic cycle is over, the remaining bacteria can continue to multiply. If these bacteria become resistant to the antibiotics, they can potentially do even more harm. It may take longer for you to recover from your illness, and your physician may have to prescribe more medication.

But overusing antibiotics can also cause resistance, especially when they're not the correct treatment. For example, if you take an antibiotic for strep throat when you only have a common cold or other viral infection, the antibiotic still attacks bacteria in your body, but not illness-causing bacteria. That's why it's important not to take leftover antibiotics or those that have been prescribed to someone else; they might not be the right treatment for your particular illness.

Talk to Your Doctor

If you're concerned about your ability to finish an antibiotic course, be sure to ask your doctor what will happen if you miss a dose. You may be able to take the forgotten pill as soon as you remember, or you may have to wait until your next dose. Don't double up on pills before checking with your physician.

If you're anxious to stop taking your prescription early, ask your doctor if it's OK -- there may be certain instances when it won't hurt to shorten an antibiotic course. One study found that a two- to four-day course of antibiotics was just as effective as a conventional seven- to 14-day regimen in eradicating a urinary tract infection in children.

It's natural to have concerns about antibiotics, but keeping open lines of communication with your doctor will give you the peace of mind that you're taking the right course of action.