Ethambutol

Brand Name: Etibi

Prescription Needed: Yes

What is this drug used for?

Ethambutol is used to treat tuberculosis. It is generally prescribed in combination with other anti-tuberculosis drugs. Combining different anti-tuberculosis drugs helps improve the effect of the medication(s) and reduces the risk of the infection becoming resistant to the drug. Ethambutol may be used for other infections. Check with your doctor or pharmacist.

Is there any reason not to take this drug?

You should not take this drug if you are allergic to ethambutol or have a condition called optic neuritis (inflammation of the eye nerve). Tell your doctor if you have or have ever had:

  • cataracts
  • problems with your vision
  • eye nerve damage
  • gout
  • problems with your kidney

What about possible side effects?

The most common side effects are:

  • nausea
  • stomach upset (may be taken with food)
  • blurred vision
  • swelling or irritation of the joints
  • increased uric acid causing gout

Some of these side effects are usually related to dose the use of other medications and other factors (e.g. older age other medical conditions). As well some of these side effects may go away with time. Talk to your doctor or pharmacist about whether you have any risk factors that may make you more sensitive to these side effects. Contact your doctor if these symptoms continue or become worse.

Other side effects:

  • eye pain blurred vision color vision loss; unable to see colors red and green - call your doctor right away

Other less common and possibly severe side effects include:

  • fever chills
  • itching
  • numbness of the hands or feet
  • rash
  • jaundice - yellowing of skin or eyes (rare)
  • headache confusion (rare)
  • thrombocytopenia (rare) - call your doctor immediately if you experience any increase in bruising or bleeding.

This is not a complete list of side effects. If you are concerned about these or other unusual symptoms while taking this medication ask your doctor and/or pharmacist for more information and advice.

What if I am taking other drugs?

Always provide your doctor with a list of all other drugs you are taking (including over-the-counter medications and herbal/natural products) as they may interact with and/or may change the safety or effectiveness of either drug. Tell your doctor specifically if you are taking any of these drugs as these are the most common interactions and he/she may need to make changes or monitor you more closely:

  • antacids containing aluminum - may reduce the effect of ethambutol; take ethambutol at least 1 hour before or 2 hours after antacids
  • certain anticancer medications - may increase the chance of affecting the eye nerves

This is not a complete list of drug interactions. Ask your doctor or pharmacist to review your list of medications.

Other information

To help clear up your tuberculosis infection completely you must keep taking this medicine for the full time of treatment even if you begin to feel better.

Laboratory tests: Ethambutol is a drug that has few side effects. With long-term use or at very high dose it may result in optic neuritis which can lead to blurring and fading of vision. A full examination of the eyes should be undertaken prior to starting treatment and your doctor will likely recommend that periodic eye tests be carried out. Vision problems are usually reversible when ethambutol is discontinued.

Your doctor may perform other blood tests to make sure the drug works properly and to decrease your chances of having side effects.

Children: Ethambutol has been tested for children age 13 years or over. It may be prescribed in certain situations when other medications cannot be used. Young children may not be able to tell if they are having side effects affecting their eyes. Talk to your doctor.

Seniors: Are more sensitive to side effects

Pregnant women: Risks and benefits should be discussed with your doctor.

Women who are nursing: This drug passes into breast milk. Talk to your doctor.

People who drive or operate machinery: Should not do so until they know how this drug affects them personally as this medication may affect your vision.

Alcohol: May increase the chance of dizziness or other side effects.

Overdose: If you experience any unusual reactions or if you seriously exceed the recommended dosage call your doctor or 911.

Stopping the drug: Talk to your doctor before you stop taking this drug. Stopping before the full course is taken may not clear up the infection. If the drug needs to be stopped your doctor will likely prescribe another medication in its place.

If you miss a dose: Take as soon as you remember. However if it is almost time for your next scheduled dose skip the missed dose and go back to your regular dosing schedule. Do not take a double dose.

Storage conditions: Closed container; cool dry location away from excess moisture (not in the bathroom) and light; always out of reach of children.

Dietary precautions: None unless prescribed by your doctor.