What is Ethambutol

Ethambutol is an antibiotic medication used to treat tuberculosis. In rare cases it can cause visual problems and loss of vision due to eye damage (ocular toxicity).

What are the risks for ocular toxicity?

You have an increased risk of ocular toxicity if you:

  • are on a high dose of Ethambutol (more than 25 mg per day per kilogram of body weight)
  • have kidney disease
  • have poor baseline vision
  • are unable to detect changes in your vision.

What are the symptoms of ocular toxicity?

You may not have any visual symptoms at all. Symptoms can include:

  • decreased or blurred vision
  • areas in the centre of vision missing
  • colours are not as bright as usual.

Why are regular eye exams important?

Damage to the eye through ethambutol toxicity is not treatable and may not be reversible, so it is important to report any changes in your vision early.

You should have a baseline eye exam within two months of starting ocular toxicity treatment with your eye care provider.

If you are at increased risk of toxicity, you will need to have a routine three-monthly exam with your eye care provider until you have stopped taking Ethambutol.

Things to remember

  • Talk to your GP or specialist about your risk of ocular damage from Ethambutol.
  • Know your dose of medication.
  • Have a baseline eye examination within two months of starting the medication and attend regular screening examinations.
  • Contact your eye care provider if you notice any visual symptoms.

Disclaimer This document describes the generally accepted practice at the time of publication only. It is only a summary of clinical knowledge regarding this area. The Royal Victorian Eye and Ear Hospital makes no warranty, express or implied, that the information contained in this document is comprehensive. They accept no responsibility for any consequence arising from inappropriate application of this information.

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  • Ethambutol Ocular Toxicity #229
  • Owner: Ophthalmology
  • Last Reviewed: June 28, 2023
  • Next Review: June 28, 2028