Antibiotics can be lifesavers, but misuse has increased the number of drug-resistant germs. See how this affects you and what you can do to help prevent antibiotic resistance.

By Mayo Clinic Staff

Antibiotics are important drugs. It would be difficult to overstate the benefit penicillin and other antibiotics have played in treating bacterial infections, preventing the spread of disease and minimizing serious complications of disease.

But there is also a problem with antibiotic medications. Drugs that used to be standard treatments for bacterial infections are now less effective or don't work at all. When an antibiotic drug no longer has an effect on a certain strain of bacteria, those bacteria are said to be antibiotic resistant.

The overuse and misuse of antibiotics are key factors contributing to antibiotic resistance. The general public, doctors and hospitals all play a role in ensuring proper use of the drugs and minimizing the development of antibiotic resistance.

A bacterium is resistant to a drug when it has changed in some way that either protects it from the action of the drug or neutralizes the drug. Any bacterium that survives an antibiotic treatment can then multiply and pass on its resistant properties. Also, some bacteria can transfer their drug-resistant properties to other bacteria — as if passing along a cheat sheet to help each other survive.

The fact that bacteria develop resistance to a drug is normal and expected. However, the way that drugs are used affects how quickly and to what extent drug resistance occurs.

The overuse of antibiotics — especially taking antibiotics even when they're not the appropriate treatment — promotes antibiotic resistance. Antibiotics treat bacterial infections but not viral infections. For example, an antibiotic is an appropriate treatment for strep throat, which is caused by the bacterium Streptococcus pyogenes. It's not, however, the right treatment for most sore throats, which are caused by viruses.

If you take an antibiotic when you actually have a viral infection, the antibiotic is still attacking bacteria in your body — bacteria that are either beneficial or at least not causing disease. This misdirected treatment can then promote antibiotic-resistant properties in harmless bacteria that can be shared with other bacteria.

Common viral infections that do not benefit from antibiotic treatment include:

  • Cold
  • Flu (influenza)
  • Bronchitis
  • Most coughs
  • Most sore throats
  • Some ear infections
  • Some sinus infections
  • Stomach flu (viral gastroenteritis)

There are likely several factors contributing to overuse. When penicillin and other antibiotics were first introduced, they were perceived as wonder drugs because they worked quickly and with relatively few side effects. They seemed like an answer to all common illnesses.

In spite of a growing awareness of antibiotic resistance in recent years, overuse still occurs for a number of reasons:

  • Doctors may prescribe antibiotics before receiving test results that identify the actual cause of infection.
  • People who want quick relief from symptoms, regardless of the cause of illness, may pressure doctors for antibiotic prescriptions.
  • People may take antibiotics purchased abroad or via the Internet for self-diagnosed illnesses.
  • People may take antibiotics that are leftovers from a previous prescription.

Failure to take an antibiotic as prescribed can contribute to antibiotic resistance. The instructions for an antibiotic tell you how many pills to take and how often you should take them. The prescription is filled so that you have the exact number of drugs you need to complete the course of treatment.

It is tempting to stop taking an antibiotic as soon as you feel better. But the full treatment is necessary to kill the disease-causing bacteria. Failure to do so can result in the need to resume treatment later and may promote the spread of antibiotic-resistant properties among harmful bacteria.

For many years, the introduction of new antibiotics outpaced the development of antibiotic resistance. In recent years, however, the pace of drug resistance has contributed to an increasing number of health care problems.

In the United States, according to a 2013 report by the Centers for Disease Control and Prevention, at least 2 million people annually "acquire serious infections with bacteria that are resistant to one or more of the antibiotics designed to treat those infections." And at least 23,000 people die annually from antibiotic-resistant infections.

The increasing number of drug-resistant infections results in:

  • More-serious illness or disability
  • More deaths from previously treatable illnesses
  • Prolonged recovery
  • More-frequent or longer hospitalization
  • More doctor visits
  • Less effective or more-invasive treatments
  • More-expensive treatments

The appropriate use of antibiotics — often called antibiotic stewardship — can help preserve the effectiveness of current antibiotics, extend their life span and protect the public from antibiotic-resistant infections. Many hospitals and medical associations have implemented new diagnostic and treatment guidelines to ensure effective treatments for bacterial infections and reduce inappropriate use of antibiotics.

The public also plays a role in antibiotic stewardship. You can help reduce the development of antibiotic resistance by taking the following steps:

  • Use antibiotics only as prescribed by your doctor.
  • Take the appropriate daily dosage and complete the entire course of treatment.
  • If you have an antibiotic prescription, ask your doctor what you should do if you forget to take a dose.
  • If for some reason you have leftover antibiotics, throw them away. Never take leftover antibiotics for a later illness. They may not be the correct antibiotic and would not be a full course of treatment.
  • Never take antibiotics prescribed for another person.
  • Don't pressure your doctor to give you an antibiotic prescription. Ask your doctor for advice on how to treat symptoms.
  • Practice good hygiene. Wash your hands regularly with soap and water, especially after using the toilet, before eating, before preparing food and after handling fresh meat. Wash fruits and vegetables thoroughly, and keep kitchen work surfaces clean.
  • Make sure you or your children receive recommended vaccinations. Some recommended vaccines protect against bacterial infections, such as diphtheria and whooping cough (pertussis).
  • If you think you may have penicillin allergy, talk to your doctor about getting an allergy skin test. Research has shown that penicillin or other antibiotic allergies may be overreported. Ruling out an antibiotic allergy can help your doctor prescribe the most appropriate antibiotic when it's needed.
Dec. 12, 2014