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Overview: Tetracycline is an antibiotic used to treat infections caused by certain bacteria. Common side effects include loss of appetite, nausea, vomiting, diarrhea, and rash. Tetracycline can make your skin more sensitive to light from the sun, sunlamps, and tanning beds. If you need to be in sunlight, wear sunscreen, a hat, and clothing that covers your skin.

Uses

What is tetracycline used for?

Tetracycline is commonly used to treat the following infections caused by certain bacteria. 

  • Infections from tick bites, including Rickettsial diseases
  • Certain sexually transmitted infections (STIs)
  • Respiratory tract infections, such as bronchitis, pneumonia, or sinusitis 
  • Certain eye infections (e.g,. trachoma, inclusion conjunctivitis)
  • Severe acne
  • An infection called plague 
  • An infection called cholera
  • An infection called anthrax
  • Certain infections spread from animals
  • Certain infections when penicillin cannot be used
  • Specific infections caused by parasites

Tetracycline may not be appropriate for some of the infections listed above, depending on which germs are causing the infection. Bacteria in some locations may have developed resistance to tetracycline, which will make it not work as well.

Tetracycline may also be used for other conditions as determined by your healthcare provider.

How does tetracycline work (mechanism of action)?

Tetracycline kills certain types of bacteria by blocking their ability to create proteins. 

How is tetracycline supplied (dosage forms)?

Brands and other names

  • Achromycin V
  • Sumycin
  • Panmycin
  • Tetracyn

Dosage forms and strengths

  • 250 mg, 500 mg oral capsules
  • 250 mg, 500 mg oral tablets

How should I store tetracycline?

Tetracycline should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place. 

Side Effects

What are the most common side effects of tetracycline?

The most common side effects of tetracycline are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Loss of appetite
  • Nausea and vomiting
  • Diarrhea
  • Rash

There may be other side effects of tetracycline that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of tetracycline?

While less common, the most serious side effects of tetracycline are described below, along with what to do if they happen.

Permanent Teeth Discoloration. Tetracycline can cause a permanent change in tooth color to yellow, gray, or brown. It may also affect growth of tooth enamel (also called enamel hypoplasia). These side effects can happen during tooth development in the last half of pregnancy and in children up to age eight years. Tell your healthcare provider if you are or plan to become pregnant. If your child is taking tetracycline and is less than eight years old, call your healthcare provider right away.

Antibiotic-associated Diarrhea. An overgrowth of germs called Clostridioides difficile, or “C. diff,” can happen in your gut with many types of antibiotics, including tetracycline. This can cause a condition known as antibiotic-associated diarrhea and can happen even up to two months after stopping the antibiotic. Call your healthcare provider right away if you have any of the following symptoms of this condition.

  • Watery diarrhea
  • Diarrhea that does not go away
  • Blood in your stool (poop)
  • Severe stomach cramps
  • Fever that starts after you start or finish the medicine

Increased Pressure Around the Brain. Tetracycline can increase the pressure around the brain, a serious condition called pseudotumor cerebri or intracranial hypertension. Stop taking tetracycline and call your healthcare provider right away if you have any of the following symptoms.

  • Dizziness
  • Nausea and vomiting
  • Severe headache
  • Vision changes

Sensitivity to Sunlight. Your skin may be very sensitive to light from the sun and devices that give off similar light, such as sunlamps and tanning beds, while you are taking tetracycline. This is called photosensitivity. Use sunscreen and wear a hat and clothes that cover your skin if you need to be in the sunlight. Exposure to this kind of light, even for a short time, can cause your skin to be severely sunburned, blistered, or swollen. Tell your healthcare provider right away if any of these happen.

Severe Allergic Reactions. Tetracycline may cause allergic reactions, which can be serious. Stop taking tetracycline and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Warnings & Precautions

Who should not use tetracycline?

Allergies to Ingredients. People who are allergic to any of the following should not take tetracycline.

  • Achromycin V
  • Sumycin
  • Panmycin
  • Tetracyn
  • Tetracycline
  • Any other medicine known as a tetracycline
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific tetracycline products they stock.

What should I know about tetracycline before using it?

Do not take tetracycline unless it has been prescribed to you by a healthcare provider. Take it as prescribed. Taking tetracycline in a way other than it was prescribed may increase the chance that bacteria will develop resistance to tetracycline. This may make tetracycline or other antibiotics not work as well in the future. Only take tetracycline for an infection if your healthcare provider has prescribed it for this reason.

Take tetracycline with plenty of fluid. Tetracycline can irritate your throat. Drinking enough fluid to completely swallow the medicine lowers this risk.

Taking antacids or supplements with tetracycline can make it not work as well. Talk with your healthcare provider about the best way to take antacids and supplements while taking tetracycline.

Do not share tetracycline with other people, even if they have the same condition as you. It may harm them.

Keep tetracycline out of the reach of children.

If you are taking this medicine for a long time your healthcare provider may check blood work. This is to monitor for any changes to your blood, kidneys, and liver.

What should I tell my healthcare provider before using tetracycline?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if tetracycline is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Kidney problems
  • Liver problems
  • Diarrhea
  • Vision problems

Other Medicines and Supplements. Tetracycline may interact with other medicines and supplements. Before taking tetracycline, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. Tetracycline may cause harm to an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. If you become pregnant while taking tetracycline, contact your healthcare provider right away.

Breastfeeding. Tetracycline passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should stop breastfeeding or stop tetracycline.

Interactions

Does tetracycline interact with foods or drinks?

Foods and drinks that are high in calcium may decrease the amount of tetracycline that your body absorbs. You should not eat or drink dairy products like milk and yogurt or calcium-fortified products at the same time or near the time that you take tetracycline. 

It is unknown if drinking alcohol will affect tetracycline, but heavy drinking can slow your immune response and make it harder for your body to fight infection.

Does tetracycline interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are taking.

In particular, make sure that you discuss if you are taking any of the following before taking tetracycline.

  • A blood thinner, which is a medicine used to treat or prevent blood clots
  • A penicillin antibiotic, which is a medicine used for certain bacterial infections
  • An antacid or supplement containing calcium, aluminum, or magnesium
  • Iron, which is a medicine used to treat/prevent low iron levels
  • A birth control pill
  • An oral retinoid (isotretinoin, acitretin), which is a medicine used to treat skin conditions, such as acne and psoriasis

This may not be a complete list of medicines that can interact with tetracycline. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much tetracycline?

If you or someone else has used too much tetracycline, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of tetracycline?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses. 

It is important to complete your prescribed course of tetracycline, even if your symptoms get better or go away. This will reduce the risk that future infections are resistant to tetracycline or other similar medicines.