Tetracyclines are a class of antibiotics that treat several kinds of bacterial infections. Examples include acne, chlamydia and traveler’s diarrhea. Tetracyclines commonly have gastrointestinal side effects, like upset stomach and nausea.


What are tetracyclines?

Tetracyclines are a type of antibiotic that work on two major kinds of bacteria. Healthcare providers prescribe them to manage and treat various bacterial infections. They work by preventing the growth and spread of bacteria.

Examples of tetracyclines

There are many types of tetracyclines, including:


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What conditions do tetracyclines treat?

Tetracyclines can treat several kinds of bacterial infections. Bacterial infections are any illness or condition caused by bacterial growth. You can get sick from getting harmful bacteria in your skin, gut (gastrointestinal tract), lungs, blood or anywhere else in your body.

Harmful bacteria from the environment, an infected person or animal, a bug bite or something contaminated (like food, water or surfaces) can cause infections. A bacterium that’s not normally harmful but that gets into a place in your body where it shouldn’t be can also cause an infection.

Bacterial infections that tetracycline can treat include (but aren’t limited to):

Healthcare providers may also prescribe tetracyclines to treat certain types of food poisoning and anthrax if you can’t take penicillin.

Other conditions

Healthcare providers sometimes prescribe tetracyclines for conditions that aren’t bacterial infections. These include:

Procedure Details

How do I take a tetracycline?

Most tetracyclines come in pill form. But they also come in the form of topical creams and intramuscular and IV injections. Your healthcare provider will give you specific instructions on how to take the medication. Be sure to follow them.

Some tetracyclines require you to take them on an empty stomach (without eating). This is because food can affect how well they work when they enter your body.

In addition, calcium, aluminum, iron and magnesium negatively affect how tetracyclines work. It’s important to tell your healthcare provider about any other medications or supplements you take. Many multivitamins, antacids and laxatives have high amounts of these substances. Your provider may ask you to stop taking them while taking a tetracycline antibiotic.

How long will I need to take a tetracycline antibiotic?

The length of time you’ll need to take the antibiotic will depend on the reason for taking it and other factors, like your overall health. Your healthcare provider will let you know how long you need to take it.

Be sure to complete your course of antibiotics — even if you start to feel better before you’re finished with them. You need to take the medication regularly until the prescription is complete to make sure it kills all the harmful bacteria or prevents them from multiplying.


Risks / Benefits

What are the benefits of tetracyclines?

Tetracycline antibiotics can treat a broad range of bacterial infections. They’re relatively safe, and healthcare providers commonly prescribe them.

What are the side effects of tetracyclines?

Common side effects of tetracycline antibiotics include gastrointestinal issues, like:

Some people have sun sensitivity (photosensitivity) while taking the medication. This can result in an exaggerated sunburn reaction, like skin blistering. Be sure to use extra sun protection (like sunscreen or wearing long sleeves) when taking tetracyclines.

Rare side effects of tetracyclines include:

Lastly, all antibiotics can contribute to the development of diarrhea related to a Clostridium difficile (C. diff) infection, including tetracyclines.


What are the risks or complications of tetracyclines?

Tetracycline antibiotics are generally safe, but there are some risks to consider, including:

Tooth discoloration

Be sure to tell your healthcare provider if you’re pregnant or think you might be pregnant. Tetracyclines cross the placenta and can affect the bones of a fetus. They can also cause permanent discoloration of the fetus’s teeth.

These antibiotics can also cause tooth discoloration in children under the age of 8. Because of this, providers don’t generally prescribe tetracyclines to children in this age group unless it’s absolutely necessary.

Antibiotic resistance

Researchers and healthcare providers have a growing concern over bacterial strains that are resistant to tetracycline antibiotics.

Antibiotic resistance happens when bacteria change, so antibiotic medicines can’t kill them or stop their growth. As a result, bacterial infections become extremely difficult to treat.

Your body doesn’t develop antibiotic resistance — bacteria do. When antibiotic resistance happens, fewer antibiotics are effective against a particular bacterium. Other antibiotics often help, but it’s important to have as many treatment options available as possible. Your provider will choose the best antibiotic for you and will follow up to make sure it’s working.

It’s important to remember that antibiotics (like tetracyclines) don’t work for the common cold, flu or other viral infections. Using antibiotics when you don’t need them increases your risk of getting an infection later that resists treatment. Only take an antibiotic when your provider prescribes it for you.

When To Call the Doctor

When should I call my healthcare provider?

If you’re taking a tetracycline antibiotic, call your healthcare provider if:

  • You have any questions about taking your medication.
  • You experience unpleasant side effects.
  • Your symptoms from the infection aren’t getting better.

A note from Cleveland Clinic

Tetracyclines are a common and generally safe type of antibiotic that treat many bacterial infections. As with all antibiotics, it’s important to finish your course of the medication. If you have any questions or concerns about the medication, reach out to your healthcare provider or pharmacist. They’re available to help you.

Medically Reviewed

Last reviewed on 08/28/2023.

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