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Overview: Ethambutol is used to treat tuberculosis. Common side effects include vision changes, joint pain, nausea, and vomiting. Contact your health care provider right away if you have vision changes. It is important to complete your prescribed course of ethambutol, even if your symptoms get better or go away. This will reduce the risk that future infections are resistant to ethambutol or other similar medicines.

Uses

What is ethambutol used for?

Ethambutol is commonly used to treat tuberculosis (along with other medicine).

Ethambutol may also be used for other conditions as determined by your health care provider.

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

How does ethambutol work (mechanism of action)?

Ethambutol helps stop the tuberculosis bacteria from multiplying in your body. This makes it easier for your body to fight off the infection and get rid of the bacteria.

How is ethambutol supplied (dosage forms)?

Brands and other names

  • Myambutol

Dosage forms and strengths

  • 100 mg oral tablets
  • 400 mg oral tablets

How should I store ethambutol?

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

Side Effects

What are the most common side effects of ethambutol?

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

  • Vision problems (see below)
  • Joint pain
  • Nausea or vomiting
  • Stomach discomfort or pain
  • Fever
  • General feeling of being unwell, tired, or not having your usual energy
  • Headache
  • Dizziness
  • Confusion
  • ​​Seeing or hearing things that others do not see or hear, also called hallucinations

There may be other side effects of ethambutol that are not listed here. Contact your health care 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 (800-332-1088). 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 ethambutol?

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

Vision Problems. Ethambutol can cause vision problems, like trouble seeing clearly, color blindness, or even, in rare cases, permanent vision loss. Keep any appointments to have your vision checked while you are taking ethambutol. If you notice any changes in your vision while taking ethambutol, contact your health care provider right away.

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking ethambutol. This can sometimes lead to death. Keep all appointments, including appointments for lab work, while you are taking ethambutol. Call your health care provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Severe Allergic Reactions. Ethambutol may cause allergic reactions, which can be serious. Stop taking ethambutol 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 ethambutol?

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

  • Myambutol
  • Ethambutol
  • Any of the ingredients in the specific product dispensed

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

Eye Problem. Ethambutol should not be used by people with optic neuritis, a condition that causes vision changes or loss.

Unable to Report Vision Changes. Ethambutol should not be used by people who are not able to notice or report changes in their vision. 

What should I know about ethambutol before using it?

Do not take ethambutol unless it has been prescribed to you by a health care provider. Take it as prescribed.

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

Taking antacids with ethambutol can make it not work as well. Talk with your health care provider about the best way to take antacids while taking ethambutol.

Keep ethambutol out of the reach of children.

It is important to keep all appointments with your health care providers before starting and while taking ethambutol. You may need vision tests and bloodwork to check on the health of your liver, kidneys, and blood. Ask your health care provider if you are not sure what tests or bloodwork you need before starting or while taking ethambutol.

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

What should I tell my health care provider before using ethambutol?

Tell your health care 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 know if ethambutol is right for you.

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

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

  • History of taking medicine to treat tuberculosis
  • Liver problems
  • Kidney problems
  • Blood disorders
  • History of gout

Other Medicines and Supplements. Ethambutol may interact with other medicines and supplements. Before taking ethambutol, tell your health care 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. It is not known if or how ethambutol could affect pregnancy or harm an unborn baby. Tell your health care provider if you are pregnant or plan to become pregnant. Your health care provider will let you know if you should take ethambutol while you are pregnant or trying to get pregnant.

Breastfeeding. Ethambutol passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should take ethambutol while breastfeeding.

Interactions

Does ethambutol interact with foods or drinks?

There are no known interactions between ethambutol and foods or drinks.

It is unknown if drinking alcohol will affect ethambutol. The risk of dizziness may be increased if you drink alcohol while taking ethambutol.

Does ethambutol interact with other medicines (drug interactions)?

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

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

  • An antacid containing aluminum
  • Probenecid, allopurinol, or febuxostat, which is a medicine used for gout 

This may not be a complete list of medicines that can interact with ethambutol. Always check with your health care 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 ethambutol?

If you or someone else has used too much ethambutol, 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 ethambutol?

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 ethambutol, even if your symptoms get better or go away. This will reduce the risk that future infections are resistant to ethambutol or other similar medicines.