Ethambutol can cause serious vision problems or irreversible vision loss. You may not be able to take  ethambutol if you have an eye problem or vision disorder.
Before taking this medicine
You should not use ethambutol if you are allergic to it. You may not be able to take ethambutol if you have an eye condition called optic neuritis (inflammation of nerve fibers behind your eyes). Your doctor will decide if this treatment is right for if you have an eye disorder.
Ethambutol can cause vision problems that may be a sign that you should stop taking the medicine. You may not be able to take ethambutol if you cannot recognize or report any changes in your vision. Young children or debilitated patients may not be able to tell someone about vision problems.
To make sure ethambutol is safe for you, tell your doctor if you have:
inflammatory eye disorders such as uveitis or iritis;
eye problems caused by diabetes;
cataracts;
liver disease;
kidney disease; or
gout.
FDA pregnancy category C. It is not known whether ethambutol will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.
Ethambutol can pass into breast milk and may harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
Ethambutol should not be given to a child younger than 13 years old.
