If optic neuritis occurs during ethambutol therapy, what is the recommended management?

• A. Reassess vision and consider stopping ethambutol and adjust regimen
• B. Increase ethambutol dose
• C. Continue unchanged
• D. Switch to pyrazinamide

Answer: (A)

Ethambutol can cause optic neuritis, which shows up as decreased visual acuity and color vision changes and is related to dose and duration. When this happens, the priority is to prevent further damage by reassessing the patient’s vision and stopping ethambutol, then adjusting the TB regimen to keep effective therapy without that drug. Depending on recovery, the clinician may reintroduce ethambutol at a lower dose or substitute another active drug to maintain the regimen. Increasing the dose or continuing without change would risk permanent vision loss, and switching to pyrazinamide alone wouldn’t maintain a proper multidrug TB regimen.