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Using medication: Using antibiotics correctly and avoiding resistance

Created: ; Last Update: December 18, 2013; Next update: 2020.

The development of antibiotics was one of the great discoveries in modern medicine. They fight bacteria and can cure life-threatening infectious diseases such as pneumonia, for which there was previously no effective treatment. But the improper use of antibiotics means that more and more bacteria are becoming resistant to this kind of medication. So it is especially important to use them correctly.

Antibiotics can save lives, but they also relieve symptoms of bacterial infections and help us recover faster. But treatment with antibiotics also has side effects. Nausea or diarrhea are common, for example.

Antibiotics are also used far too often, and improper use is widespread. This has caused many different types of bacteria to become resistant (unresponsive) to antibiotics. Because resistance has become more common, many diseases cannot be treated as well as they could in the past.

When using antibiotics, it's important to know the following things to prevent resistance and side effects:

  • Antibiotics only work against bacteria. Many infections are caused by viruses and can't be treated using antibiotics – examples include respiratory illnesses such as a cough, stuffy nose, bronchitis or the flu.
  • Excessive and improper use of antibiotics causes side effects, and in the long term reduces their effectiveness.

What is antibiotic resistance?

In medicine, bacteria and other germs are said to be resistant if they are especially able to withstand exposure to external influences. For example, most germs that enter the stomach with food will be killed by stomach (gastric) acid. But some bacteria are covered with a mucous coating that protects them from the acid. They are resistant to gastric acid.

Resistance to antibiotics works on a similar principle: The bacteria have acquired a new property that protects them from the antibiotic. Some types of bacteria can produce a substance that makes certain antibiotics ineffective, for example. Bacteria that can protect themselves from several different antibiotics are referred to as "multiresistant."

What causes resistance?

Many of the bacteria that are now resistant used to be sensitive to antibiotics. There are a few developments that played a role in this. To put it briefly, one kind of antibiotic could originally neutralize a certain type of bacteria and then effectively stop the infection. But the genetic material of bacteria can change by chance, sometimes creating new properties. If they protect the bacteria from an antibiotic, then the bacteria have become resistant. These kinds of properties can also transfer from one type of bacteria to another.

If antibiotics are used very often, resistant bacteria are better able to reproduce because the other non-resistant strains of bacteria are stopped. Antibiotics then no longer help against infections caused by resistant bacteria.

Which bacteria are resistant to antibiotics and why are they dangerous?

Strains of Streptococcus and Staphylococcus bacteria are often resistant to antibiotics. One example is called “methicillin-resistant Staphylococcus aureus” (MRSA). Staphylococci can be found on skin and mucous membranes and may cause infection – for example if they get into open wounds.

Resistant strains have now developed in other types of bacteria, such as Escherichia coli, Klebsiella and pseudomonads.

What is being done about antibiotic resistance?

In Germany, antibiotics are prescription-only. This means that doctors are first and foremost responsible for careful and appropriate use. They are to first see whether someone actually has a bacterial infection. If they do, then it's important that the antibiotic is prescribed at the right dose and for long enough, and that the right antibiotic is selected that will most effectively fight the bacteria.

There are also hygiene regulations to keep resistant bacteria from spreading further and preventable infections from occurring. These measures are especially important inside of a hospital. Antibiotics are used there relatively frequently, so resistant germs can develop quite quickly. If you come into contact with someone who has an infection of resistant bacteria, it can help to wear disposable gloves, a mask and coat, and to use a hand disinfectant to stop the spread of the germs.

Antibiotics are also used in veterinary medicine and in agriculture. Veterinarians also have to comply with the rules for handling antibiotics properly.

What can I do to prevent antibiotic resistance?

Being cautious when taking antibiotics can help prevent both antibiotic resistance and side effects.

The most important thing is to not overestimate what antibiotics can do: Patients often expect antibiotics to be prescribed to treat medical conditions for which they are not suitable.

Antibiotics are needed to treat serious bacterial infections like lung infections or meningitis (inflammation of the membranes lining the brain and spinal cord). This is not the case when, for example, people who are otherwise healthy have respiratory infections caused by viruses, such as a cold or influenza (“the flu”). Antibiotics will usually be of no help because they only fight bacteria. Antibiotics also have side effects including allergic reactions, stomach and bowel problems, nausea and fungal infections. Because of these associated risks, it's important to carefully consider the advantages and disadvantages of taking antibiotics.

What's important to consider when taking antibiotics?

Antibiotics should be taken for as long as the doctor has prescribed them. Just because the symptoms of the illness subside, it doesn't mean that all of the germs have been killed. Remaining bacteria may cause the illness to start up again.

If there are some tablets left over, they should not be kept for later use or given to other people. Leftover medication can be disposed of in the normal garbage or dropped off at some pharmacies. Pharmacies are not obligated to accept opened medicine though. It is important not to dispose of the medication by pouring it down the drain or flushing it down the toilet. That is bad for the environment and also contributes to bacterial resistance.

Medications can only work properly if they are used correctly. It's important to know the following things when taking antibiotics:

  • Can the tablets be broken into smaller pieces to make them easier to swallow? Doing this can stop some medications from working properly.
  • What food can you take antibiotics with? Antibiotics are usually taken with water because taking them together with fruit juices, dairy products or alcohol can affect how the body absorbs some drugs. Dairy products include milk as well as butter, yogurt, and cheese. After taking an antibiotic you may need to wait for up to three hours before eating or drinking any dairy products. Grapefruit juice and dietary supplements containing minerals like calcium may also work dampen the effect of antibiotics.
  • When should you take antibiotics? Some antibiotics are always meant to be taken at the same time of day, others are meant to be taken before, with or after a meal. If you are supposed to take the medicine three times a day, for example, it usually needs to be taken at set times so that the effect is spread out evenly over the course of the day. You could remember the regular times of 6 a.m., 2 p.m. and 10 p.m. for an antibiotic that needs to be taken every 8 hours, for example.
  • Can you take antibiotics together with other medications? Because antibiotics can interact with other medications, it's important to tell your doctor if you take other medications too. Antibiotics might interact with some blood thinners and antacids, for example. Some antibiotics can make birth control pills less effective.

You can find detailed information on the use of a specific antibiotic in the package insert. If you're not sure about what is important to consider when taking the antibiotic, you can ask your doctor or pharmacist.


  • Bundesministerium für Gesundheit (BMG), Bundesministerium für Ernährung und Landwirtschaft (BMEL), Bundesministerium für Bildung und Forschung (BMBF). DART 2020. Zwischenbericht anlässlich der WHA 2016. May 2016.
  • Centers for Disease Control and Prevention (CDC). Antibiotic / Antimicrobial Resistance. June 12, 2017.
  • Deutsche Gesellschaft für Infektiologie e.V. (DGI). S3-Leitlinie: Strategien zur Sicherung rationaler Antibiotika-Anwendung im Krankenhaus. AWMF-Register-Nr.: 092-001. December 15, 2013.
  • Kayser FH, Böttger EC, Deplazes P, Haller O, Roers A. Taschenlehrbuch Medizinische Mikrobiologie. Stuttgart: Thieme; 2014.
  • Weltgesundheitsorganisation (WHO). Antimicrobial resistance. October 2016.
  • IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

    Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. We do not offer individual consultations.

    Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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