Why should I finish my antibiotics when I’m feeling better?

Many uncomplicated bacterial illnesses such as strep throat or ear infections respond quickly after starting treatment with antibiotics. This can lead to people failing to complete the entire course of prescribed treatment. Why then, considering the expense and risk of side effects, should we heed the common medical advice to complete an entire course of prescribed antibiotic treatment? In short, the two primary reasons why an entire course of a prescribed antibiotic should be taken are:

1. Failure to take antibiotics in the proper dosage, or for as long as prescribed, runs the risk that the infection will not be adequately treated, leading to a persistent or recurrent infection.
2. By not taking the entire course of antibiotics, resistant bacteria may develop that no longer respond to common antibiotics. This has the potential to turn easily treatable infections into serious ones.

Inadequate treatment: Taking antibiotics for the full duration prescribed is the best way to assure that harmful bacteria causing the infection are completely eradicated. Shortening the course of treatment may only wipe out the least dangerous bacteria while allowing the less sensitive bacteria to survive. This risks a recurrence of the infection, which can sometimes be even more difficult to treat.

Scientific studies are continuously being conducted to determine the minimal period of time necessary to take antibiotics for various bacterial infections. Doctors use this information in recommending the dosage and length of treatment. While some antibiotics must be taken for 10 days or more, others are approved for a shorter course of treatment. For example, in the case of an uncomplicated urinary tract infection, the antibiotic course may be as short as three days. These recommendations occasionally change based on the development of new antibiotics or on the results of additional research.

Development of resistant organisms: According to the Centers for Disease Control and Prevention (CDC), virtually all significant bacterial infections in the world are becoming resistant to antibiotics. Stopping treatment early is one of the factors responsible for this. With inadequate treatment, bacteria undergo changes in their DNA that makes them no longer susceptible to common antibiotics. This can lead to the need for stronger, more expensive antibiotics, or in some instances, resorting to surgical treatment for what once was an easily treated infection. Other factors contributing to the development of resistant bacteria include prescribing antibiotics for inappropriate reasons, as well as taking antibiotics for a longer period of time than recommended.

Obviously, health care providers have a major responsibility to make sure that antibiotics are prescribed appropriately. Additionally, the CDC recommends that consumers of medical care follow these recommendations in order to improve treatment outcomes and to avoid complications from antibiotic use:

• Take antibiotics exactly as the doctor prescribes. Do not skip doses. Complete the prescribed course of treatment, even when you start feeling better.
• Only take antibiotics prescribed for you; do not share or use leftover antibiotics. Antibiotics treat specific types of infections. Taking the wrong medicine may delay correct treatment and allow bacteria to multiply.
• Do not save antibiotics for the next illness. Discard any leftover medication once the prescribed course of treatment is completed.
• Do not ask for antibiotics when your doctor thinks you do not need them. Remember antibiotics have side effects. When your doctor says you don’t need an antibiotic, taking one might do more harm than good.
• Prevent infections by practicing good hand hygiene and getting recommended vaccines.